Getting Frustrated

idaho_88

New Member
Dec 1, 2005
15
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Boise,Idaho
I'm getting frustrated... My 88 GT is a 5-speed and has a weird problem. Whenever I am coming to a stop and get ready to shift from 2nd to 1st, and brake, my car dies. It doesn't die every time, just occasionally. I just got it back from the shop, which told me my brake booster was bad. They changed it and also bumped the timing up a little. I had a charging system check a couple weeks ago and everything was good. What else could be wrong? I just bought this and just want it to run smoothly. Thanks for any help.
 
Check the IAC. Various sources show that the no-load warm idle adjustment for SD cars requires IAC to function and flow properly (different than MAF).

How is the cold idle and loaded idle? Is your VSS hooked up?

Absent other ancillary info, I would clean the IAC for starters.

Good luck.
 
Not that it apply's to you but and don't laugh my dads 86 diesel jetta would't stop the engine when the key turned off. but when you touched the brakes when the key was off it would kill the engine. turns out a ground in the rear brake light assemble was loose and it was causing the problems. In your case i would say IAC. You can remove it and clean it up. Perhaps when you are comming off the gas the computer is not getting the Throttle postion correctly. You can check to make sure you have about .96 volts on that sensor. no more the 1.00 volts and no less then .8 i believe.
 
Thanks Hissin

Thank you for the quick response. I will try out the IAC tommorrow, as far as cleaning it. Should I go back and get my money back for a new brake booster? The article you recommended is awesome. I let you know what happens.
 
I cant say on the booster. If the old one was really leaking, it needed replacement for safety's sake. Normally the brake pedal will get hard or feel like you really have to push hard to slow the car (like how it feels if you coast to a stop with the car off).

If you are still SD (the assumption for now), the vacuum signal is critical for the engine management (one reason to replace a leaky booster). So before if there was a leak, the computer thinks you have the throttle pressed down when you dont (while at idle). And ironically, a vac leak would have raised your idle up, and allowed the idle to hang high upon coming off the throttle. So this might have masked the underlying issue which you are now dealing with.

If you want to check your vacuum, a stockish motor should read about 18-20" hg at idle.

We should also have noted that retrieving the trouble codes is always a good place to start. A SD stang does not have a functional CEL (even though there is an outline for one). A very wise man in here named Jrichker very often posts links and info on retrieving the trouble codes.

Good luck bud.