# Car "stumbles"



## noquacks (Jun 5, 2010)

Hi People, again,

Well, another of my cars, an 80's sunbird, TBI, has many new parts, and I DO keep it up. But, Ive ben living with this for say, 7-8 years now- You start the car , reverse slowly to back out of garage by letting out clutch normally, then, as the car reaches the point where you push in the clutch and prepare to brake (before puting into 1st to take off), the engine almost dies!

Its like, one would expect the engine to even rev up especially since the clutch has been disengaged, and less load on engine, but , noooooo, it gets even worse by almost stalling!

Happens worse when cold. It behoves me as to why the engine gets stalling when one would depress clutch and lessen load on engine. Vacuum leak? I checked for that sooo many times. new AIC valve, new TPS, Oh well, just taking a chance here. Tips/feedback always appreciated.


----------



## reelangler (Nov 18, 2011)

You said 80's so im guessing you have a carb if so it sounds like a normal engine warming up. Does this only happen after car has sat overnight or a long period of time?


----------



## noquacks (Jun 5, 2010)

Actually, 88, and I mentioned TBI. I dont remember car doing this when new. Thanks!


----------



## housegsx (Oct 21, 2010)

Does it have an IAC (Idle Air Control) valve? It could be stuck or broken not allowing air to bypass the throttle plate. Reason it stays running when in gear is because of the vacuum while in gear.


----------



## noquacks (Jun 5, 2010)

housegsx said:


> Does it have an IAC (Idle Air Control) valve? It could be stuck or broken not allowing air to bypass the throttle plate. Reason it stays running when in gear is because of the vacuum while in gear.


Yes, has an AIC.....NEW. And the old one wasnt even broke! It was a gamble, you know, before I knew how to test them. 

I still have a hunch its vac related, just havnt ben able to identify it yet. Its hard!!


----------



## reelangler (Nov 18, 2011)

noquacks said:


> Actually, 88, and I mentioned TBI. I dont remember car doing this when new. Thanks!


Oh ok i missed that try cleaning and re gapping your plugs


----------



## johnniebravo (Oct 4, 2011)

With that setup I would also suspect vacuum lines. what us the condition of the pcv valve?


----------



## noquacks (Jun 5, 2010)

well, thanks guys, but new/gapped plugs periodically (recently, a few mionths ago, after which, no change), and pcv valve tested OK, but you know, heck- I have a new one sitting around, maybe I'll put it on (duhhhhhhh)
(still, I strongly am pessimistic, too easy)

I will advise on this asap!


----------



## noquacks (Jun 5, 2010)

Oh, I should say, the EGR valve has been yanked years ago- car ran way worse with it than with the EGR tube removed and stoppered with wood dowel.....LOL


----------



## AnErin (Nov 24, 2011)

so when you pulled the EGR, you plugged the vacuum line (if it isn't an electrical EGR) and the passages for the EGR yes?
Also what engine are you running?


----------



## noquacks (Jun 5, 2010)

AnErin said:


> so when you pulled the EGR, you plugged the vacuum line (if it isn't an electrical EGR) and the passages for the EGR yes?
> Also what engine are you running?


Right, Erin, I plugged the line. Now, coincidentallly, this morning, I popped in my new PCV, and car runns better, does not stumble nearly as bad. Im happy for now. Thats to the above member who suggested that!

BTW, why does my car run worse with the EGR connected?


----------



## Marty1Mc (Mar 19, 2011)

It's probably because the EGR valve was partially open. It is only suppose to open at certain conditions. But, if it sticks open (they do get clogged), it will feed back exhaust gas all the time. It will cause the car to stumble and sometime die.


----------



## noquacks (Jun 5, 2010)

thanks, makes sense, but egr was new when I installe dit. Its a mystery to me. I know about the diaphragm in that valve, btw. Its closed/tight. And, theyre so expensive too!


----------



## Marty1Mc (Mar 19, 2011)

Next time, pull the vacuum from the EGR solenoid and plug it, then see if it makes a difference. A leaky solenoid will do the same thing.


----------



## AnErin (Nov 24, 2011)

is there any chance that at some point in repairs, vacuum hoses could have been swapped? I once did that on a ford I used to own cause there were 3 vacuum lines real close and easy to swap by mistake. Check the vacuum diagram if there is one, of course on my stupid car I didn't have nor could find one on the web and had to look at a junkyard car and make my own.


----------



## rusty baker (Feb 13, 2009)

Could be choke.


----------



## noquacks (Jun 5, 2010)

Marty1Mc said:


> Next time, pull the vacuum from the EGR solenoid and plug it, then see if it makes a difference. A leaky solenoid will do the same thing.


Thnaks, Mart, but I dont believe my TBI Sunbird has a solrnoid......


----------



## noquacks (Jun 5, 2010)

AnErin said:


> is there any chance that at some point in repairs, vacuum hoses could have been swapped? I once did that on a ford I used to own cause there were 3 vacuum lines real close and easy to swap by mistake. Check the vacuum diagram if there is one, of course on my stupid car I didn't have nor could find one on the web and had to look at a junkyard car and make my own.


Doubt it- Im the original owner, and have been meticulous about that stuff. But, hey, it was an idea/though.


----------



## noquacks (Jun 5, 2010)

After driving it now for about a week since I put in that new pcv, runs much better. Im convinced that was needed badly. 

Still, the EGR bugs me. People, I know youve been trying, but Im about to give up on this EGR. Im kinda used to now, after about 9 yrs, driving with the egr off, and while its a doggone mystery to me, I may have to accept it. Gotta be thankful- heck, who has an 87 GT non turbo still as a daily driver WITH working ac and original clutch?????? LOL


----------



## AnErin (Nov 24, 2011)

you might be able to scout the junk yards for an EGR price ranges from like $10 to $30. 
Or $55 at autozone. That is assuming you have a non-turbo
If it is electronic, you might be able to take it apart enough to clean the passages and make sure the solenoids are not hanging up. 

If you get a vacuum one at a junkyard, they are easy to test - put a section of hose on the thing and just suck air and see if the plunger moves like it should. You should be able to draw air thru it but that should stop real quick once the plunger bottoms out. The only things that can go wrong with a vacuum EGR itself are the diaphragm ripping or the plunger sticking. IS there vacuum at the line for the EGR?

Also, you do know how to pull the codes on older cars yes? If the check engine light is on, I believe there is a plug under the dash and you turn off the car, put a jumper between two of the contacts, turn the key on but don't start the engine, you may hear the engine fan kick in, and the check engine light flashes... code 12 means the test is starting, code 55 means it is done...
all other codes you will have to look up. here is how it would look.
Say you had a code 44 (JUST for sake of demo here)
One flash for the "1", brief pause, two quick flashes for the "2", then a bit longer pause, 
four quick flashes, brief pause, four quick flashes, a bit longer pause, 5 quick flashes, brief pause, 5 more quick flashes. that would mean it has the codes 12, 44, 55 stored. It will flash 12 and 55 even if no other codes are there.

Also, sometimes the codes can be misleading if something else is giving a bad reading to a sensor. Example, say a car had a blocked exhaust. Well, I know from experience that this will make the computer thing there is a problem with the TPS and the MAP sensors, even if there isn't. 

So, kind of take the codes with a grain of salt but it can give a starting point. BTW I don't thing a vacuum EGR system that old will have a way of knowing if it is bad, unlike the electronic EGR.

All that aside, for now just concentrate on the EGR and making sure it is good, and don't forget a new gasket.


----------



## noquacks (Jun 5, 2010)

AnErin said:


> you might be able to scout the junk yards for an EGR price ranges from like $10 to $30.
> Or $55 at autozone. That is assuming you have a non-turbo
> If it is electronic, you might be able to take it apart enough to clean the passages and make sure the solenoids are not hanging up.
> 
> ...


EGR is brand new from AZ from years ago, of course. But, yes, maybe I should test it to be sure and rule it out. Its non electronic, so wouldnt set a code specificallly for it. Also, no codes as "check engine light" is not on. I know all about codes and the Diagnostic Connector under dash.

Now, I should follow up on your idea of making sure my vac line for the egr IS pulling a vac- I believe I did this yrs ago (cant remember everything) but can do again. Any idea of how much vac is should pull in inches of mercury?


----------



## noquacks (Jun 5, 2010)

Geez- AnErir was right! Just tested the egr vac line from the intake, and there is NO vacuum!! Zero! Man, now I gotta dig deeper to find out why- will ba removing the air cleaner, etc, and see if theres a plug somewhere . Could be that tiny black plastic/rubber vacuum line is rrotted/bad. Gimme an hour or so, guys..........


----------



## noquacks (Jun 5, 2010)

OK, that was quick- I found out there is NO vacuum on the EGR port at the TBI itself! Also, no vac on the port at the TBI for the port that goes to the vapor canister! Geez, no wonder. But, there IS vacuum on the MAP sensor line/port. What could be causing that? I also inserted a piece of steel wire down the port serrated fitting/tip ruight under the tbi to "feel" if there was a plug/crud obstructing it but nothing- wire went in and out so easy, without any junk to push through. 

Any ideas as to whats going on?

Thanks!


----------



## noquacks (Jun 5, 2010)

more info: regarding vapor canister ports- there are 2 it looks like- one narrower than the other. There is suction on the narrow port/line, but not the wider port/line. Shouldnt BOTH posts connected to the canister be sucking in from the canister and have vacuum?


----------



## noquacks (Jun 5, 2010)

After 2 days of testing, EGR tests out OK with vacuum of 6" mercury at 2000 rpm (like manual says). So, if egr is OK, what else could be the culprit causing rough performance/idle? Well, the vapor canister tested out as a FAIL. Upon applying 15" Hg vac, and closed the tap, the vac dropped to zero within 3 seconds (manual says should hold to 20 seconds).

So, canister Vacuum diaphragm internally is shot. I dont care if some vapors go unburnt (cant be that much), but question: could a bad/shot canister cause rough idling/interfere with egr performance?

can I just detach the 2 tubes going to the canister from the 2 ports in back of the TBI? (kinda "tie" them together)?

Thanks!


----------



## cjm94 (Sep 25, 2011)

Hook a vacuum gauge to direct manifold vacuum and check vacuum. Is the vacuum steady our does the needle bounce? If it bounces you could have burnt valves that would cause poor idle but run ok down the road.


----------



## noquacks (Jun 5, 2010)

Thanks, CJM. I actually noticed that as I was doing the vacuum work at that time, and kinda pay attention to that stuff- so, yes, the vac guage showed about 20-22" Hg, but not say, bouncing around, but more like fluctuating (slowly undulating back/forth between the 20-22 marks, Id say every 2 seconds it would reach say, 22, then in 2 seconds it would arrive to 20, then repeat. I heard this is called a "hunting" idle. 

Any ideas? Could burnt valves (the exhaust?) cause hunting? Just to note- I have pretty good compression, so could one have say 145psi with burnt valves??


----------



## cjm94 (Sep 25, 2011)

Slow fluctuation isn't always bad. Burnt valves should be fairly fast if bad enough to run bad. You can show normal cranking compression with burnt valves. Is that still distributor in 88? If it is how is the distributor shaft is it tight. At that age I have seen loose shafts cause rough idle. What is the state of the ignition system.


----------



## noquacks (Jun 5, 2010)

CJ, big thanks for your continued support/advice. 

Yes, has a distributor cap. OK, so lets rule out it has burnt valves as vac guage is definitely not "jittery". Dist cap is new, plus rotor. Now, car does have 180,000 miles on it, and yes, dist (shaft) is original. I did a head gasket on it in 2002 (112,000 miles), and didnt notice then a loose shaft. Also, valves looked acceptable. But, I did not reseat them with valve paste (if it matters). Still, if bad valve seat, shouldnt that show as bad compresion?

Rest if ignit system: new plugs about 6 months ago, wires- kinda new (lifetime). coil new. new ignit module too. Car starts every time. Dang- why cant I get a handle on this rough engine with EGR connected..........
If you and me cant figure this out, I may disconnect it again and run it without as I had been for years. Just was , with renewed hope, wanting to revisit this again, as it happens time to time when one want to challenge prioblems again.

thanks


----------



## noquacks (Jun 5, 2010)

Oh, to be technical, shop manual , in the egr section testing, says: engine vac at 2000 rpm in the egr line should be less than 6" Hg. I got about 3". Guess that means its good/correct vacuum and good egr.........Oh well.

And why do they call it exhaust gas recirculation when it is mounted on the INTAKE, not exhaust manifold??????? How can the egr resuck exhaust from the intake if exhaust goes out the other side????????


----------



## housegsx (Oct 21, 2010)

It pumps the exhaust gas into the intake system. Not the other way around.


----------



## noquacks (Jun 5, 2010)

housegsx said:


> It pumps the exhaust gas into the intake system. Not the other way around.


Thaks, House, but still- how can it pump exhaust gas if its mounted on the imntake manifold? I dont get it.


----------



## housegsx (Oct 21, 2010)

It's mounted on the intake manifold, but there should still be some type of EGR tube coming from the exhaust system. When the EGR valve opens the vacuum and pressure from the exhaust pumps the spent gases back into the intake.


----------



## noquacks (Jun 5, 2010)

housegsx said:


> It's mounted on the intake manifold, but there should still be some type of EGR tube coming from the exhaust system. When the EGR valve opens the vacuum and pressure from the exhaust pumps the spent gases back into the intake.


LOL....Hey man, I know youre trying to help me understand this,. but there is NO "some type of EGR tube coming from the exhaust system", period. 

Unless, perhaps you mean to say that somehow, the exhaust kinda blows back into the cylinder and makes its way through the intake valves BACK out to the egr??

Thanks again, house.


----------



## housegsx (Oct 21, 2010)

I don't know what your system looks like but perhaps there is an internal exhaust port through the intake manifold and head.


----------



## noquacks (Jun 5, 2010)

OK, I get ya now. maybe. Guess if I want I can look up the drawing in the shop manual- maybe theres something in there that may show the port innards. But, thanks for the persistence in helping me understand, house!


----------



## noquacks (Jun 5, 2010)

OK, after searching /rresearching more, Ive concluded the only thing it could be is its a defective/off spec EGR valve. It IS aftermarket, and Ive learned lots of people warn of this- too late for me to return it- bought it 9 yrs ago. For now, Im gonna unplug the vac hose and stopper it up. I also have not noticed any pinging/knocking as a result. Whats the harm, right?


----------



## housegsx (Oct 21, 2010)

No harm. They are not open during idle or WOT I believe. Only cruising at partial throttle. Just emmisions junk.


----------



## noquacks (Jun 5, 2010)

housegsx said:


> No harm. They are not open during idle or WOT I believe. Only cruising at partial throttle. Just emmisions junk.


Right , house, no egr on both idle and WOT (I learnt this in all my research...LOL). You do need to be aware of pinging though- can be serious. If pinging is that "ticking" noise when one cruises/accelerates (timing too advanced), I dont have it (although, I understand, the ECM does correct for it if it happens). 

Thanks, Man!

(on to my honda civic ac comp project.......other thread)


----------



## MecGen (Mar 26, 2011)

Oh Boy 

I don't think this is a type of problem for a DIYer. You had a very good reply about checking codes, did you? It has nothing to do with your check engine lite, also in these years GM has what called a "data stream" which is a valuable tool for a competent technician. The fact that you unplugged your EGR for years can lead to problem of carbon caking giving other symptom exactly of what you are describing. Yes there is an internal exhaust port and an vacume port in the Intake manifold. EGR is MUCH more then an anti pollution device, in the 80s when computerized engine controls came mainstream, lots of old school techs and backyard mechanics blew them off as "anti-pollution". False.

My suggestion would be research intake valve deposits, problematic TB gasket and TB warpage, GM data stream and pid values.

Sorry to be so vague on the reply but rough idle problem are rarely an easy fix.

Good luck


----------



## noquacks (Jun 5, 2010)

MecGen said:


> Oh Boy
> 
> I don't think this is a type of problem for a DIYer. You had a very good reply about checking codes, did you? It has nothing to do with your check engine lite, also in these years GM has what called a "data stream" which is a valuable tool for a competent technician. The fact that you unplugged your EGR for years can lead to problem of carbon caking giving other symptom exactly of what you are describing. Yes there is an internal exhaust port and an vacume port in the Intake manifold. EGR is MUCH more then an anti pollution device, in the 80s when computerized engine controls came mainstream, lots of old school techs and backyard mechanics blew them off as "anti-pollution". False.
> 
> ...


Thnaks. No "check engine light " on. But, do you mean a Scan Tool? I could buy one if it comes up for sale on ebay. If you think that would help. Now, to you, running without the rge could show up as pinging. If YOU would not hear any pinging or clickety clackety (or tick-tick-tick) in the engine while running, would you conclude you are running the engine timing as safe? isnt the ECM for 87 GM suppose to compensate for pinging should it happen?

Thanks


----------



## MecGen (Mar 26, 2011)

Ok I'll try to answer these


noquacks said:


> Thnaks. No "check engine light " on. But, do you mean a Scan Tool? I could buy one if it comes up for sale on ebay. If you think that would help.


In all OBD systems there are priority to the codes, not all will give a "CE" (check engine) on dash, some are secondary faults that won't lite the dash but will give you a indication on whats going on. Did the unplugged EGR give a CE lite? I don't remember, its been a while since I worked on an older GM here in the salt belt they are long gone. Buying a scanner with a the capabilities of reading a data stream could be useful altho depending on your skill level could be overwelming as well. Mid to late 80's car were a piss off to diagnose, the first generation OBD systems where unreliable and not vary precise to say the least.



noquacks said:


> Now, to you, running without the rge could show up as pinging. If YOU would not hear any pinging or clickety clackety (or tick-tick-tick) in the engine while running, would you conclude you are running the engine timing as safe?


No, if you hear ping things are already going way bad, knock sensors pick up small frequency noises and are often problematic of of being over sensitive.



noquacks said:


> isnt the ECM for 87 GM suppose to compensate for pinging should it happen?


Yes

Two different things here, static and calculated (computed) timing
The job of an egr has nothing directly to do with ping, ping is a symptom not a fault. Ping = Pre ignition. The job of an EGR is to lower the temperature of the combustion chamber, reducing certain pollutants, (true high combustion temp can cause ping among other things), thus giving the ECM a easier time to adjust other perimeters that effect performance, fuel economy, and anti-pollution. An ECM (brain) thinks in 3D, its usually called strategies. This is way too complicated for me post, I type real slow  but basically unplugging an egr shift many calculation to the left a bit effecting mostly fine tuning, like a car with a funny stumble or whatnot. Unplugged whatever puts your car into a limp mode, not optimal for anything.

What I think is going on with your car, -put a "without looking at it" disclaimer here - unplugging the EGR for so long causing #1 combustion temperatures to run too hot, in turn causing carbon deposits on the intake valves outside of combustion chamber #2 in turn playing with fuel mixture #3 ECM is trying to adjust timing #4 ECM is trying to adjust fuel mixture #5 normal wear and tear of motor after 25 years These cars are known for a bad TB gasket and sometimes the TB warping. All these symptoms altho nothing is majorly f-ed up, show up as poor performance between hot and cold. Again very difficult to diagnose even for a licensed tech.
What I would do in your shoes, check for a vacum leak around the base of the TB, take it to a shop and pay a one hour diagnosis, it might cost you less in the long run.

I am sorry if my posts come off as arrogant, its not meant to be so, its just on forums I have a hard time expressing my demeanor. Sorry if I missed something.

Good luck


----------



## housegsx (Oct 21, 2010)

Yes, GM tries using EGR to compensate from running water temps WAY too hot. I learned this from working on C4 Corvettes. If you do block off the EGR, I'd recommend keeping an eye on water temps and possible putting in a lower temp T-stat and a fan switch.


----------



## noquacks (Jun 5, 2010)

Sorry for delay- ben busy putting together my civic ac (other thread). But, thanks, Mac and house. Guess some history is in order:

My egr is not elec, but just vac type, so wouldnt give "feedback" to the ecm. Still, when unplugged, no check engine light. Yes, I know unplugging it is bad, but man, the car runs so sloppy with it connected (cruise only), and soooooo smooth without. Funny you brought up the hotter radiator/engine, and I did install a simple toggele switch a year ago for the fan!! 

Mac, I did spend some $$ on this years ago- got me nowhere. They just done get excited on working on sunbirds. The dealer told me I needed a new cat, AND FI. They were grasping at straws. I still have the same cat. Bought myself a new FI and was for nothing. Dealers......

I dunno- I always heard an egr is responsible to lower temps in combustion , higher temps which can cause detonation (or pre ignition?), oh well, whatever- can never get them 2 straight- either of whioch is not good for engine, thats the point. You say its just for lowering NO3/NO2, (by allowing for lower temps, without which the no3/no2 gasses would be worse. )

So, where to go from here. I will be osting a link to a youtube soon- think t will help? Its showing the vac gauge at idle. Maybe its a shot, eh?


----------



## noquacks (Jun 5, 2010)

OK, here it is- not sure if it is relevant to my egr problem, but this is what I have on my car:

http://www.youtube.com/watch?v=Zs4QTWqPTOQ&feature=youtu.be

undulating vacuum at idle, fluctuating about 1-2 " mercury. Any ideas? This I believe may be even unrelated to my egr running roght at cruise speed. Still, if I can fix this bad vac, its a win.


----------



## MecGen (Mar 26, 2011)

Hi
The thing is your vacum is pretty good, the idle sounds to be going up and down so that is why your vacum gauge follows. I really hate the fact that the garage can't get you a strait answer, kudos for doing what you thought was right and refusing the work. Did you check for a vacum leak at the base of the TB? this can be done with a spray bottle and plain water, or a hose...beleive it or not if you have a vacum leak it will suck the water into the intake causing it to run like crap. Have you made a block off plate for the egr? If the cat is partially plugged it can push the EGR pintle off his seat and carbonizing it partially open, this has nothing to do with unplugging the vacum line. At this point I would need to see your O2 voltage (still plugged) and your Map sensor output. 

X-mas is coming I'll try to help as much as I can.

Regards


----------



## noquacks (Jun 5, 2010)

MecGen said:


> Hi
> The thing is your vacum is pretty good, the idle sounds to be going up and down so that is why your vacum gauge follows. I really hate the fact that the garage can't get you a strait answer, kudos for doing what you thought was right and refusing the work. Did you check for a vacum leak at the base of the TB? this can be done with a spray bottle and plain water, or a hose...beleive it or not if you have a vacum leak it will suck the water into the intake causing it to run like crap. Have you made a block off plate for the egr? If the cat is partially plugged it can push the EGR pintle off his seat and carbonizing it partially open, this has nothing to do with unplugging the vacum line. At this point I would need to see your O2 voltage (still plugged) and your Map sensor output.
> 
> X-mas is coming I'll try to help as much as I can.
> ...


Big thanks, Mac. Yes, I did check for vac leak under the TBI- madderafac, I checked for vac leak EVERYWHERE....LOL

I did use the "stethescope" method, as I find it is the most useful, and no flammables hazard. No vac leaks anywhere. Dang.

At a time, I did block of the EGR base. I also did some known cat tests in the past- forget exactly what they were, but they indicated no blockage. 

O2 sensor was put in 2 yrs ago- check engine lt went on cuz of a bad O2 sensor, and upon installing new one, no problem. MAP I believe was tested based on Haynes manual test. Its ok. Also, no codes for it. I know "no codes" may not always prove its not at fault. 

I was thinking (hard to do these days with internet distractions), maybe a leakdown test? I heard a 1-2-3 " fluctuation in n vac can indicate leaky valves?? What do you think, Mac?


----------



## MecGen (Mar 26, 2011)

Quick reply 

Bad valves bounce a vacum gauge. Needle moves really sharply, not what I saw on Youtbe.

Regards


----------



## noquacks (Jun 5, 2010)

MecGen said:


> Quick reply
> 
> Bad valves bounce a vacum gauge. Needle moves really sharply, not what I saw on Youtbe.
> 
> Regards


Hmmm, ok, good observation. Guess no need to chase that leak down test. ya know, its nice weather out right now (actually, its nice here almost all yrear- LOL), so lemme do that spray water mist at the base of the TBI and confirm. Then we can go to the next thing............(engine still hot from geting home early from work- its the early release program today cuz of the Christmas weekend....)


----------



## noquacks (Jun 5, 2010)

OK, that didnt take long. Water spray all over TBI base, and vac lines all around. Even sprayed the spark plug wires/dist cap, rotor, etc. No change in engine rpm's. Then I even lit up 2 insense sticks (got them from the wife- she had strawberry flavored ones), and they smoked up some, ran the sticks of smoke all around the vac lines.tbi base. No suctioning of that smoke. No detectable leaks anywhere. man, we gotta be looking elsewhere. 

OR, we can call it quits. Geez. Hate to have yoou guys here chasing a ghost and all. Heck, lived with it for 9 yrs now. Running out of idea.


----------



## Bigplanz (Apr 10, 2009)

Maybe check the distributor gear and shaft for wear. Highly unlikely to be the cause but if you checked everything else it's worth a check.


----------



## frenchelectrican (Apr 12, 2006)

I know I am late in here however I did not get a chance to see what engine you have in your car if you have timming chain it can streched and can screw up the timming and valves.

A quick tip to tell if you have streched timming chain is use the timming light and timed at #1 hole or #1 sparkplug and read it then move the pick up sensor 180 degrees around if you have 4 banger you should do that on #3 hole ( IIRC they are at 1-4-3-2 ) but for 6 bangers they will varies a little so do at #1 then go 180 degrees and read it again you should have the timming marks line up straight if got off then you know the answer.

The other thing is check your catatic converter konck on them it should sound soild if rattle then you know it shot but few case it can get plugged as well ( you will catch this pretty fast at mid speed range but idle the vac will fall down pretty steady pace ) 

Merci,
Marc


----------



## noquacks (Jun 5, 2010)

Merci', monsewer. Now, Its a 2.0L non turbo sunbird GT 1988. 4 cylinder. It has a timing belt, not chain. Now, I understand that once you line up the timing marks/notches , and you place the belt on, if youre off 2-3 mm, it makes no difference as the ECM will compensate for that (not to mention sometimes, with a new belt, its impossible to even get the timing marks perfect as the belt "teeth" will never accomodate that. ) I tried to put the belt on the next notch, and its worse, so one doesnt have much choice but to "minimize" the difference and settle for the closest notch/timing marks one can get.

I will try your idea on the timing light and the 180 degree thing...........


----------



## noquacks (Jun 5, 2010)

believe it or not, these Brazilian engines dont even have a timing scale to time with- I understand these engines done need it as it doesnt matter. I scratched my head over this for a year or so a while back- timing is all controlled by the ECM- aint no matter ifn the dist cap is rotated a bit one way or the other.


----------



## frenchelectrican (Apr 12, 2006)

noquacks said:


> believe it or not, these Brazilian engines dont even have a timing scale to time with- I understand these engines done need it as it doesnt matter. I scratched my head over this for a year or so a while back- timing is all controlled by the ECM- aint no matter ifn the dist cap is rotated a bit one way or the other.


There is few other ways you can get the timming mark set up depending on what you like to do with this engine and I can list few here real quick

First one and this is genrally my favour methold is get a penical or long wood stick and slowly bar the engine over ( do not use the electrique starter ) while your helper hold the wood stick or penical and when the pistion is top dead centre ( TDC ) then take a blowgun and lightly blow in the plug hole and listen or feel which way the air going out if none then you nail it right if you hear air leaking either intake or exhaust or some case both then you have to bar the engine 360 degrees or a full turn over then it will line up correct.
NOTE: Becarefull with this you can bar the engine real fast with air build up in the cylinder and it will not take much to bar it over quick so don't use too much pressure.

Second methold is flywheel timming same techine as I mention above and some engine will have a notched flywheel so you can use them to indentcating where it the TDC { most larger diesel engine are done this way } I know old Dodge engine with van verison they are marked in this manner cuz you can run the timming light at the flywheel housing. 

Few automotives engines are done this methold so that is the other spot you have to take a look.( mine VW diesel engine is done this way by look at flywheel )

Other methold I used from time to time is camshaft timming this is little more trickier but I will explain later if you are instering to hear how I done this.

Merci.
Marc


----------



## noquacks (Jun 5, 2010)

Well, yes, there is a notch cut- but into the crankshaft pulley (not the same as a flywheel, right?). I wonder why they instaled a pulley with a notch and yet with no timing scale. Sheesh.

A few yrs ago, I took a shot at this- I guessed that timing should be at point about 11:30 position (from axial view, from the perspective of viewing the front of the engine from the crankshaft end/side)) using flashing timing light. I kinda guessed. I ran engine at idle, pointed the light at the pulley, and turned the dist cap counter clockwise and got it timed with slight advance. I was afraid though, to advance it too much for fear of overheated piston. I retarded it some and reduced the pinging, which can destroy your engine even if affording a more powerful acceleration. 

better safe than sorry. Thats why in part, I still have a reliable 2.0L after 180,00 miles........


----------



## frenchelectrican (Apr 12, 2006)

noquacks said:


> Well, yes, there is a notch cut- but into the crankshaft pulley (not the same as a flywheel, right?). I wonder why they instaled a pulley with a notch and yet with no timing scale. Sheesh.


There is a reason for notched pulley is some of the timming devices can use the magatic probe to pick up the marking and go from there.

That how most modern gaz engine are timmed and few diesel engines done same manner.

Merci,
Marc


----------



## CATliftTech (Nov 20, 2011)

After reading the original post, and the posts since, I wonder why the clutch isn't suspect. The clutch is the original equipment installed at the factory. This vehicle is 23 years old, the clutch is the same one? I'm not familiar with an 88 Sunbird, does it have a hydraulic actuator? My guess, and it's only a guess, is, your problem is there in the components of the clutch, not the engine control systems. The pilot bearing could easily be hanging up on the input shaft, in which the transmission isn't disengaging from the engine, even if the clutch does.


----------



## noquacks (Jun 5, 2010)

CATliftTech said:


> After reading the original post, and the posts since, I wonder why the clutch isn't suspect. The clutch is the original equipment installed at the factory. This vehicle is 23 years old, the clutch is the same one? I'm not familiar with an 88 Sunbird, does it have a hydraulic actuator? My guess, and it's only a guess, is, your problem is there in the components of the clutch, not the engine control systems. The pilot bearing could easily be hanging up on the input shaft, in which the transmission isn't disengaging from the engine, even if the clutch does.


Sorry for late reply, but clutch is original, and madderafac, I have had this rough idle problem for about 9 yrs now, no I doubt it is clutch, if we should blame the clutch for being now, 23-34 yrs old.

I have no reason to suspect transmission- I have always babied it. I have no "crawl" with clutch pushed in with gear say, in 1st. I just done see how that could be, but hey, thanks for posting- you never know. 

Any feedback apPRECIATED


----------



## CATliftTech (Nov 20, 2011)

I think that's "matter-of-fact". Your original post stated you had a problem with the vehicle almost stalling when backing up and pushing the clutch in. That's what I was addressing. I'll study the posts again for rough idle.


----------



## noquacks (Jun 5, 2010)

CATliftTech said:


> I think that's "matter-of-fact". Your original post stated you had a problem with the vehicle almost stalling when backing up and pushing the clutch in. That's what I was addressing. I'll study the posts again for rough idle.


Right, Cat- I think the thread morphed to the rough idle now, and yes, a member here actually hit it right on the nose sugesting the pcv valve. With a new one, the car does not stumble anymore, and Im very happy. I hope I did not also confuse anyone else here with this- yes, I still have that annoying rough idle, but the car stumbling as I reverse and release clutch is gone!! 

So, any tips appreciated.( have not had any luck playing with the timing light/timing pulley mark, etc. Seems to not have had any change)


----------



## noquacks (Jun 5, 2010)

This may help- when I floor the pedal with hot engine, of course, accelerate, and shift going to 5000 rps, the car accelerates excellently!! No stumbling.roughness. I had not mentioned that before, I think. Its just at idle.....


----------



## noquacks (Jun 5, 2010)

After 60+ posts here, and after 9 years of living with the "stumbling idle", I thinbk I might have fount it, people!!!!!! Youre not gonna believe it- I decided this past weekend to tackle my timing belt/serpentine/and wile I was at it, the water pump. Cripe- I noticed that timing belt was slack/loose!!! Man, thats got to hace a bad effect on idle, right? Then, upon studying how to remove the water pump to get to the timing belt, it hit me- I never tightened the water pump back in 2003 when I did a head gasket (the pump is on a "cam" style design where turning it will tighten the belt). 
\

Boy, did I miss this step way back in 2003!!! Ran for 9 years!! But, lets not celebrate yet- lets wait til I actuially DO put on the belt, and line up the cut notches, and tighten the belt the right way!!!

I cant wait! (while Im at it, Im putting on a new crank seal, and cam seal...)


----------



## Marty1Mc (Mar 19, 2011)

noquacks said:


> After 60+ posts here, and after 9 years of living with the "stumbling idle", I thinbk I might have fount it, people!!!!!! Youre not gonna believe it- I decided this past weekend to tackle my timing belt/serpentine/and wile I was at it, the water pump. Cripe- I noticed that timing belt was slack/loose!!! Man, thats got to hace a bad effect on idle, right? Then, upon studying how to remove the water pump to get to the timing belt, it hit me- I never tightened the water pump back in 2003 when I did a head gasket (the pump is on a "cam" style design where turning it will tighten the belt).
> \
> 
> Boy, did I miss this step way back in 2003!!! Ran for 9 years!! But, lets not celebrate yet- lets wait til I actuially DO put on the belt, and line up the cut notches, and tighten the belt the right way!!!
> ...



So, is there an update???


----------



## noquacks (Jun 5, 2010)

Marty1Mc said:


> So, is there an update???


Sooooory Marty, for LATE update- but beter late than never- after all the work, , which needed to be done, all seals worked well, and no more leaks. BUT, as a bonus, I was expecting the timing to be better, and no change. Oh well, even after tightening the belt nicely, eliminating slop, no change. Mystery continues. 

At least, I wont hav to worry about getting stuck on HWY on account of the oil pump. Its perfectly fine. 

A new pcv valve did improve the stumbling, I believe I reported that already......


----------



## Carkid0007 (Jan 24, 2012)

johnnyfreud786 said:


> Hi, nice thread. I am looking for an auto body expert for my Nissan car near my down town. It has compression as well as suspension problem. Some work of auto glass also needed to give it a new look. Any recommendation.
> 
> Auto Body


What's it doing ? Or not doing ?


----------



## noquacks (Jun 5, 2010)

Carkid0007 said:


> What's it doing ? Or not doing ?


OK, carkid- it "stumbles" but only at idle. Now, at th advice of a fellow member here (probably burried in this thread a while ago) I did replace the PCV valve and that got rid of the problem of the car almost dying when say, I back up a few yards then push clutch in to prepare to shift to 1st, right there, the car almost dies. That was corrected by the new PCV valve- cheap easy fix.

But, still, at idle, the car runs rough/a litle spitting/stumbling. Now, let me warn you- Ive been chasing this for TEN years. No luck. Changed just about everything. 

Whew- well now you know the rest of the story. I , a few months ago, changed the tiiming belt, as you know from thread above. I thought maybe because the old one had some slop in it that may have ben the cause, but no such luck. Dang........


----------



## Carkid0007 (Jan 24, 2012)

Iacv been changed as well ?


----------



## noquacks (Jun 5, 2010)

Carkid0007 said:


> Iacv been changed as well ?


Whats that? Idle air control valve? Yes, new (and old one was still good, learned afterward by testing it). See what I mean! Everything new. Everything new , Sheesh.......


----------



## Carkid0007 (Jan 24, 2012)

Coolant temp sensor ?


----------



## Autobell (Jul 14, 2011)

*Stumble*

Does your car have power brakes? You might look at the check valve attached to the booster , it will have a rubber vacuum hose from the manifold going to the booster, take plastic check valve could be defective, very cheap to replace.


----------

