hey guys, I have a problem with my truck in the sig. ill be driving and my go pedal is very sensitive all of a sudden, the truck will pick up speed and then lose it. its very touchy when i accelerate from a stop, almost spins the tires.. very annoying when theres a cop behind ya. any ideas on what it might be? checked for codes, gonna take the superchip out tom. to see if it helps. what do you think?

 

Sounds like it could be the gas pedal assembly itself. There is a small variable resistor on the pedal that sends pedal position to the PCM via a varying voltage. It is known to fail. I don't think they are available any more from Ford. Others will probably chime in with a test procedure which I can't find. If that is your problem you might find one in a junk yard. Not sure if they are fixable/rebuildable.

 

I wonder if the Idle validation switch is sticking. Does it do mainly coming off idle? Could also be a bad spot in the TPS. I do have a pedal assembly I would like to sell if you figure out that is what is wrong with it.

 

oops double post!

 

yes it acts up taking off mostly and a little while driving. any way to test? tps is on the pedal too right? took out my programmer and she still does it. i called ford a while back for my brothers truck(thought he needed a pedal and seen your sig tj) and they said the 95 wouldnt work on a 97 but then again they do hire the handicapped. is it a good time to try the hot pedal?

 

I have looked my (97) pedal compared to this 95 (even plugged it in and used it) and it worked fine. I am not sure why they list a different pedal for the 95 and older and the huge price difference.

To test the TPS you can use and ohm meter with the connector unhooked or a voltmeter with the connector hooked up and the key on. its hard to test with a meter as the sample rate is just too slow some times but if you can get a graphing meter or osciliscope its best. You are just looking for nice even change in the voltage/resistance.

To test the IVS its either open or closed so any sticking or bad connection will render it useless. The way the whole deal works is that the PCM will not look at the TPS voltage until the IVS completes the circuit (or is it opens the circuit?). So it you push the pedal to half throttle and the IVS doesn't do its thing then pops open/closed you will go from 0 to 50% throttle in an instant. Some times the IVS just needs to be cleaned and lubed with WD40 or some thing like it.

 

TJ, I agree with everything you said except the part at the end about using WD 40 as a cleaner/lube. I've found that when the propellant evaporates it leave the sticky lube that just attracts dust and makes the problem as bad it as was originally. I like the electronic contact cleaner from Radio Shack but even plain old brake cleaner works.

 

Stay away from brake cleaner on electrical parts.
One time i grabbed the wrong can to clean up some contacts
on a marine application and it melted in front of my eyes.

My vote is for the electrical cleaner.
Some of the brake cleaners are sensor safe, but i donot take the chance anymore.

Bill

 

so should i take the ivs off and spray the button that gets pushed in by the pedal? thanks for the replies fellas

 

Yes! And once you get the switch out you can remove the little rubber boot that goes around the plunger, that'll give you better access to the interior of the switch. I had a dead spot on my pedal and cleaned it with the Radio Shack cleaner and haven't had a problem with it since. Yesterday I was at Walmart and saw that they sell sensor safe electronics cleaner. I think it was made by CRC

 

well took off the ivs and cleaned it and shes good as new! real happy with the advice you guys rock. i dont know know much longer i could stand it.

 

CRC the stuff in the red can will melt plastic connectors. Had it happen on my F250.

 

X2 yeah i found that out the hard way too my friend. i should have known better!! but i made sure the can said electronic cleaner for that priceless piece of gold on the go pedal