# idle surge (cold), dies when put in reverse (sometimes)



## de-nagorg (Feb 23, 2014)

Now if this was an old Carburetored engine, I would tell you that your automatic choke spring was weak. 

But these are controlled electronically now.

Have you checked the air filter for dirty?

These are sensitive to a restricted air flow, and a dirty air cleaner will cause it to run poorly, because the sensors test the exhaust for the proper mix, and if not present it adjusts looking for where to run best.

Sounds Complicated? It is because the computer ain't programmed with everything that can occur, just the average things.

Air filter is my first thing to check.


ED


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## Bigplanz (Apr 10, 2009)

Air filter, less than two months old.


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## Windows on Wash (Aug 30, 2011)

Carbon in the intact track and a dirty IAC.

Start by running a top end cleaning. Should reset the trims on the IAC and see how it runs after that.


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## Bigplanz (Apr 10, 2009)

Windows on Wash said:


> Carbon in the intact track and a dirty IAC.
> 
> Start by running a top end cleaning. Should reset the trims on the IAC and see how it runs after that.


What is this? "top end cleaning"?


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## Windows on Wash (Aug 30, 2011)

If you are going to do it yourself, you don't have access to some of the chemicals and tools that are run for top end cleaners (i.e. BG for example).

There are some DIY options.


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## de-nagorg (Feb 23, 2014)

Bigplanz said:


> Air filter, less than two months old.


Time is not a good measure of weather the filter has clogged or not, Depending on the environment in which the car was ran in , the filter can clog in a week, but you are not in a coal mine. 

So maybe it has developed some deposits in the injectors, and intake system. 

So like WOW suggested a top end cleaning might help.


ED


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## lenaitch (Feb 10, 2014)

Windows on Wash said:


> If you are going to do it yourself, you don't have access to some of the chemicals and tools that are run for top end cleaners (i.e. BG for example).
> 
> There are some DIY options. https://www.youtube.com/watch?v=O5N_Z1W6mho


WoW(or anybody else) - have you used the Seafoam spray top cleaner and found it effective? I have not seen Barryman's up here although it is on Amazon. Some YouTube clips praise one over the other but as always, we don't know how unbiased they are. Tnx


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## carmusic (Oct 11, 2011)

on my old car i had to remove the throttle assembly to clean it, it was very dirty and caused poor idling.


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## Windows on Wash (Aug 30, 2011)

lenaitch said:


> WoW(or anybody else) - have you used the Seafoam spray top cleaner and found it effective? I have not seen Barryman's up here although it is on Amazon. Some YouTube clips praise one over the other but as always, we don't know how unbiased they are. Tnx


I have used some of the "top end" foam cleaners with some measured success. I now use a BG induction system cleaner that seems to do the trick.


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## Brainbucket (Mar 30, 2015)

Check engine light on? BG stuff is real good. So it AC Delco 66 or 66X. I use MotorVac. I just dip an old tooth brush in the bottle and scrub the throttle body and plate, (butterfly). If you don't have a throttle cable, it's drive by wire so turn the key on a have someone step on the gas peddle to open the throttle. I then spray the intake with a tool I got from BG. If that doesn't work, IAC ( Idle Air Control ) is prolly to blame if you don't have vacuum leak when cold. If you have vacuum leak when cold, intake gaskets.:vs_cool:


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## papereater (Sep 16, 2016)

Not intending to hurt anyone's feelings, but Seafoam is clearly just another snake oil remedy- so many on the market.


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## papereater (Sep 16, 2016)

Windows on Wash said:


> I have used some of the "top end" foam cleaners with some measured success. I now use a BG induction system cleaner that seems to do the trick.


Win, what is a "BG" cleaner? Any brands you can tell us about?


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## papereater (Sep 16, 2016)

No need to search, Win, just found whats in there:

1-Methyl-2-Pyrrolidinone 872-50-4 15 - 40
Xylene 1330-20-7 10 - 30
Distillates (petroleum), hydrotreated light 64742-47-8 5 - 10
2-Propanol 67-63-0 5 - 10
Acetone 67-64-1 5 - 10
Ethylbenzene 100-41-4 1 - 5
Composition/information on ingredients

Interesting. Solvents, some of which are already in our gasoline as as additives to keep our engines clean......Still, might have its merits ........


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## Windows on Wash (Aug 30, 2011)

Depending on the nature of the malfunction, there is nothing "snake oil" about Seafoam. If the nature of the hesitation is a carbon track IAC pintle or passage, Seafoam could easily clean that up just as any number of other cleaners. 

Don't look for it to be miracle in a can, but it isn't in the Slick 50 family of products.


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## Brainbucket (Mar 30, 2015)

Seafoam is ok. But it's not as strong as BG, 66 or 66X or motorvac. Now on the crap that is in intakes now-a-days. Before ethanol, intakes hardly ever 'coked' up meaning deposits in the intake area. Now it's bad. I believe it's the ethanol in the gas. We didn't see it until ethanol was added to fuel. Remember the 'white' tailpipe of yesteryear? That was the lead in the fuel and when you seen the white tailpipe, you car was tuned correctly. Wasn't running rich. Now a days it's a black tailpipe because lead was takin away. Since ethanol was added, deposits are everywhere in the intake system. To remedy this is to 'flush' the intake system. I like every 50,000 miles or every tune up some of which is 100,000 miles. At 100,000 miles stuff is collected and rock hard. 50,000 miles it catches it while it is still somewhat soft and is easily removed with the flush. Now this post is just my opinion from 39 years working in this field so I have seen it change from no coking of the intake to stalagtights (sp) and stalagmites in the intake system. Now on to the 5.4 engine. Clean the throttle body first. If that doesn't work, smoke your intake system while the engine is cold. You will then find your intake leak. Check your PCV hose back by the throttle body. The "T" hose collapses and a vacuum leak will be there and you won't hear it. ( I just thought of that):vs_cool:


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## Bigplanz (Apr 10, 2009)

A short vid of the cold idle issue.


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## Brainbucket (Mar 30, 2015)

That looks like a vacuum leak or a bad IAC. Clean throttle body first.:vs_cool:


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## Windows on Wash (Aug 30, 2011)

Yep. Get you and old toothbrush and some cleaner. 

Just unbolt and the IAC and clean all the passages.


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## Bigplanz (Apr 10, 2009)

it hasn't thrown a code, btw. Somebody asked.


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## Brainbucket (Mar 30, 2015)

I asked. That means no lean codes to direct you. I wonder what your fuel trim reads. You will need a scanner to read them. That will tell you if your lean on start up then reads ok warmed to operating temp. Intake gaskets. If your not and the fuel trim stays ok, then IAC. I have found the IAC reading are ok but the IAC is not doing right. Change it and all's well. Fords are bad about that. Clean the throttle body. Look in it and if you seen black stuff, it needs cleaning.:vs_cool:


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## Bigplanz (Apr 10, 2009)

I'll check it out this w/e. Supposed to be sunny and in the 70's.


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## Bigplanz (Apr 10, 2009)

Fully warmed up, it will run fine but still die when I put it in reverse. Fortunately, the IAC valve is right on top of the engine, no access problems at all. I will test it first, though.


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## Bigplanz (Apr 10, 2009)

Follow-up question: The haynes manual says "do not attempt to clean the interior of the throttle body as it is coated with a special sludge resistant material.' I have CRC throttle body and air intake cleaner, which I have seen widely used on the Internet and in practice. Just spray it in? Rubbing on the interior with even a soft tooth brush would seem potentially damaging to the Throttle body coating.


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## Brainbucket (Mar 30, 2015)

I've seen that but cleaned them anyway. Works fine. They said that years ago. They also said you can't clean/flush the cal-tech fuel injectors on older Chevys as it will strip it of the protective coating and kill the injector. Well the injector needed to be replaced so I cleaned it. Worked fine. I'm suspecting that your IAC is bad. Fords are real bad about that. If the throttle body is coked up and they said don't clean, it will have to be replaced. Clean it anyway. It will be fine. Done hundreds of them and not one failed.:vs_cool:


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## de-nagorg (Feb 23, 2014)

I'm thinking that the "coating" would be a ceramic , and should be OK to scrub with a nylon brush, just not any metal brush, or scraper. 

But wait until others have a chance to confirm or repute this idea.


ED


edit: Brain Bucket posted while I was composing my answer.


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## Brainbucket (Mar 30, 2015)

Never metal brush or scraper. I use a old tooth brush with MotorVac. Works like a charm. After you clean it, it will be hard to start. Once it starts, just rev it a few times and it will clear out. When Ford started the 'coating', it was said that it was the same stuff that was on the inside of tv tubes. I don't know. But I never had a problem after cleaning them. It always ran fine.:vs_cool:


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## Bigplanz (Apr 10, 2009)

I used an old toothbrush and some throttle body cleaner and cleaner out the throttle body today. Idles better, much better. Still dies when I put it in reverse or come to an sudden stop.


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## Windows on Wash (Aug 30, 2011)

Did you clean the IAC? They take a while to reset the IAC tables when they are cleaned.


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## Bigplanz (Apr 10, 2009)

How do you clean it (IACV)? Just spray cleaner in it (after you take it off the car, or course)? Spray in the two holes? Do you tooth brush it too?


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## Brainbucket (Mar 30, 2015)

The way the idle is acting, it a bad IAC. I have cleaned them but it hardly ever worked. Like I said, it will look good on the scanner but it isn't as that is false. The computer tells it to be in this position and it will show that it's in that position, but it's not because the 'gears' are stripped.:vs_cool:


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## Bigplanz (Apr 10, 2009)

I will swap out the IAC next time I get paid. From the vid, you can see it is right on top of the engine and easy to get on and off. Cleaning the throttle body helped the over all idle of the car. Idle is smooth, performance seems a bit more peppy. Put it in reverse though, and it dies. One out of every 20 stops at stop lights, just dies. Starts right back up.


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## TheMechanic (Dec 16, 2016)

Vacuum leak. Check pcv elbows and check the rubber 45* elbow behind throttle body area. Spray around plastic intake gaskets. The leak probably seals up a little when it warms up. If you have a scanner you can tell if it is a vacuum leak by short term fuel trim data.


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