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93 Grand Prix 3.1L SE - Engine coughs - 10 MPG - Gutless - Run rough

93 Grand Prix 3.1L SE - Engine coughs - Bad mileage

When the car is idling, and you step on the gas, it is REALLY rough, and and hesitates, and then once you press harder and get more RPM it goes up, still a bit rough, and then all of the sudden, it surges as if it's getting no fuel. then keeps revving, then surges again and again. The entire car runs very very rough, and gets about 10 MPG, though it just super gutless. We just got it inspected and it passed emissions, to our surprise. This happened just a while ago, and sometimes, it could instantly click back to normal, run smooth again, and I'd have about 70% more power for a small period of time, then just as quick, it would go back into the above mode.

Any thoughts? I replaced the EKG Gasket, because the inspection guy said it was not sealing correctly, and was letting air in, but that did nothing.

Reply to
Darrell with DieselBenz.info
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if you can get the computer codes,that may help. but a common problem like this is caused by temp sensor. it tells computer how hot/cold engine is.and the oxegen sensor is another culprit that causes this problem. you can get at parts house to see what it looks like. auto zone can pull the codes for you for free ,that may help. lucas

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Reply to
ds549

Bad plug wires.

Reply to
=?x-user-defined?Q?=AB?= Paul

Hi there Darrell,

Looks like we are experiencing the same problems. I presently own a 98' Grand Prix SE with a 3.1L engine too... and I've been trying to figure this problem out for the past few months.

This is what I've done, (1) changed the spark plugs and the wires, (2) checked the Mass Air flow sensor, (3) even changed one of the ignition coils since I managed to figure out that it is the middle cylinder in the rear block that was causing the problem, but the ignition coils were not the source of the problem, it came back again, (4) and I'm presently running some injector cleaner in my fuel tanks... hoping that it's clogged injectors that are the source of the problem. The injector cleaner helps to ease the jerking a bit... but the problem is still there. I'm really stumped by this issue... so if anyone got a solution to this, I'm sure glad to find out.

I'll try to looking up on the forums on how to determine a faulty O2 sensor... and I think it the source of the problem is a sensor... since it's so erratic.... like you said, one time is goes crazy, and the next... it's running smoothly.

I've checked most forums.. and your present situation is the closest that is to mine.

Cheers, Tantor

Reply to
Tantor

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