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

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

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Darrell with DieselBenz.info - 10 Nov 2005 12:43 GMT

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.

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ds549@webtv.net - 10 Nov 2005 15:14 GMT

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

http://www.minibite.com/america/malone.htm

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=AB Paul =BB - 11 Nov 2005 01:21 GMT

> 93 Grand Prix 3.1L SE - Engine coughs - Bad mileage
>
[quoted text clipped - 11 lines]
> 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.

Bad plug wires.

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Tantor - 22 Nov 2005 17:22 GMT

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

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