96 Gt 3.1L Surging Problem

Whenever the car is cold , it surges heavily and stalls but after about 5-10 min it runs perfect. Its a 96 GT 3.1L auto w about 111,000 km or about 70,000 miles... I just bought the car last week.....

It sounds like you may have a vacuum problem of some sort. Or a problem with the air intake. I will send a private message to one of the other guys on the forum that may be able to help you out. Watch the forum for more responses.

First of all steeler, do you have any check engine lights / service vehicle soon lights?

There's several possibilities of what could be causing this that come into my mind. One, like Hoags said, would be a vaccuum leak. To detect a vaccuum leak, here's a few things you can try: Take a section of hose, put one end up to your ear, and then move the other end around the engine, if you suddenly hear an increase in noise through the hose, that's most likely your leak. Another way is too take something like ether or starting fluid and spray it on the vaccuum hoses while the engine is running. If you hear a sudden increase in idle RPM, then there's where your leak is (the engine's sucking in ether = more power = increased revving).

Next, I would try checking your TPS (throttle position sensor). It's located on the side of your throttle body. It may have a leak and be taking in condensation or water, giving it a bad signal, resulting in erratic idle. But then when your engine heats up, it dries out the TPS, and it gets a proper signal = no more bad idle. So I would deffinately consider just replacing the TPS (it'll be like 30 $) - but it's worth replacing, even if the TPS doesn't neccesarily "look" bad, it may be.

Another thing to check would be your IAC (Idle Air control) motor. It is in the top of your throttle body. Here's what you should do. Buy a can of Throttle Body Cleaner spray. Pull off your whole intake all the way to the throttle body. Remove your IAC motor. Spray the hell out of the IAC cavity in the TB, and the TB itself, and throttle plate several times. Just essentially use the whole freakin can on the throttle body and IAC cavity - clean the motor itself too. But when you clean the motor, only clean the spindle end - don't shoot any TB cleaner into the motor itself. But essentially clean the hell out of the throttle plate, throttle body, pivot hinges, IAC cavity, and the IAC motor. Cleaning the throttle body good should also help with rough idle.

Another thing would be your EGR valve. It may be stuck open or shut or have some other missfucntion - and it may not throw a code. But you can pull it off, shoot it full off "break away pentrating-oil", and then carb-cleaner, and let it dry - this should fix it if it's sticking in one position. Then reinstall it.

Beyond those things, pull a few of your spark plugs and check to see if they're fouled. Here's a chart to help you determine if they're fouled or not. If they are fouled, (which they shouldn't be) you can either buy anti-foulers, or buy different plugs.
http://img96.exs.cx/img96/7487/charttempfiringend6um.gif

Also, check your wires for burns, cracks, or breaks. This could be a contributing factor. One last thing would also be to have your coil packs tested - but I'm guessing this would be a very much lower possibility compared to the other possiblities.

Oh, almost forgot, it's not a bad idea to run some cleaner through your engine. High mileage engines usually have major carbon build-up, which could be contributing to your problems. Buy 1 can of "Seafoam" cleaner, dump 1/2 of it in your oil pan, and dump the other 1/2 of it in your gas tank. Buy 1 bottle of Fuel-Injector cleaner too, and pour all of it into your gas tank.

Good luck steeler - shoot back with some questions if you have any.
Good luck.

By the way, welcome to AF

O hey almost forgot - it could also possibly be related to a bad MAF or a bad IAT sensor. But try that other stuff first (which it is much more likely to be), and then we'll go from there.

thanx guys I'll see if i can't figure it out tomorrow....


I'll let u know how it goes.....