# 94 chevy sliverado 4x4



## Sean Lay (Aug 21, 2010)

My truck loses power sometimes going down the road, then cuts
back on. And sometimes you have to pat the gas to get it to start.
What could the problem be.


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## TJ_in_IL (Aug 24, 2009)

Neutral Safety Switch? Had this happen on my 97 Mercury. Just a thought. TJ


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## Billy_Bob (Sep 11, 2008)

Best to do a bit of testing to at least find out what the problem is "not'!

Otherwise if you just start replacing parts, it can get to be quite expensive...

If this problem is like you took your foot off the accelerator suddenly, then if you have a timing light, rig it up to one of the spark plug wires and tape the trigger on. Then tape it sticking out from under the hood so you can see the light flashing while driving.

Then test drive. When the problem occurs, see if the light is still flashing (still getting spark). If yes, then spark is not the problem!

Next I would get a factory service manual set of 4 books and test the following fuel related sensors with a multimeter per the instructions...

Throttle Position Sensor - More fuel
Coolant temperature sensor - Lean/rich
Oxygen sensor - Lean/rich
Atmospheric (barometric) pressure - Lean/rich
Manifold Absolute Pressure - More fuel
(Mass Air Flow Sensor)

If those sensors check OK, then next I would test the wiring and connectors to those sensors for loose connections or intermittent shorts to ground. You can do that with a recording multimeter and a "giggle test", or with "live data" computer software like this...
(And an assistant to drive while you look at the computer of course!)
http://winaldl.joby.se


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