Is this a common problem with the 94 Grand AM?

[svasica]

I just bought a 1994 Grand AM 3.1L, and it does some WEIRD stuff! When I'm cruising along on the highway, all of a sudden the engine will start studdering, like it's missfiring, and shake. I replaced the ignition wires, the coil packs, and had the ignition module that is underneath the coil packs replaced. Under heavy acceleration, you can feel something like the car is misfiring, but also does it VERY bad when just cruising along, not accelerating. What could this be? Is it a common problem?

[Haunz]

It's a sensor problem... for sure...

which sensor is the question...?

[svasica]

Well, the TPS has been replaced, so it can't be that.

[live4ball]

a friend of mine had the same problem with a 2000 Elantra. It would be fine while it was accelerating, but when it was idleing or cruising it would shake and vibrate horribly. It turned out that it was the engine mounts. He's getting them fixed tomorrow. I'll tell you how it turns out...

[Jason Lesbirel]

An engine stutter feels quite different from an engine mount failing......and the engine mounts for the 3100 are significantly larger and stronger than one syou'll find on a four-cylinder vehicle.
Plus an engine mount won't cause acceleration problems - unless it's just dropped the motor on the ground...... :lol:

I occasionally experience a similar problem, and as it turns out the fuel filter can cause a variety of things to go funny.

Have you had it changed recently? It's a regular maintenance piece, and really should be done every year and a half or so, depending on how often you drive.

While you're at it, check the air filter - severely clogged air filters have been known to cause driveability problems.

There's another possibility - the 'puter's going off. The only way to find out if it's dieing is to get a diagnostic test done at the dealership.

Try the filters first.

[svasica]

Thats interesting you should mention the fuel filter, because it was changed by the former owner, but it was rusted into place so it had to be cut out, and then the new one had to be put back in place with a rubber house....can this possibly be the problem? The engine will do this strange studdering when cruising along.....when accelerating hard, the engine will do something similar, but not as badly, kinda feels like the engine is just "giving up".

[John95GA]

'Sounds like the same thing I've been dealing with on my 95. I didn't see you mention changing the spark plugs? Have you tried that? That is the next thing I am going to try, plus changing the coil packs. My mechanic change my wires and that seemed like it brought it back to normal, but I still get that problem you're describing occasionally. Also, how old is your battery and alternator?

[454SuperSport]

i am glad someone else has this problem. my girlfriends 94 grand am 3.1 is doing the same thing. it does it really bad sometimes but not all the time. we have changed the fuel filter, plugs, wires, air filter, cat. converter, muffler, tps, and map sensor and it is still doing it. it feels like the engine dies for a second and catches back over and over. it also shuts off when coming to a stop every now and then. anybody got a fix for this yet?? please let me know

[John95GA]

Could it also be the O2 sensor? I don't know why that might cause it, but maybe someone could explain how that could possibly be the problem (?).

[slam2316]

that has happened to me a couple of times intermittenly, then one day I pulled off the egr and the throttle body to clean out the carbon buildup between the two and when everything was put back together it did that really bad and it took a while for it to go away, i drove it for about ten miles and on and off i would floor it and it would shake and shudder and when i let go the speedo would go 70-35 really quick then go back up to 70 and it wouldnt accelerate when floored. It would accelerate gradually. One thing to mention is when everything was taken apart only the egr gasket was changed since i couldnt find the throttle body gasket anywhere in town, it had to be special ordered. but after that drive i parked it and just let it run for about 15 minutes and it smoothed it out. when i got back home i broke out the haynes and looked in the troubleshooting section. under stumbles on acceleration is states one of the causes as a vacuum leak in the intake manifold (the old throttle body gasket) but my guess is it sealed itself back up. hope someone can take what i said and maybe improve upon it or figure something else out. It still does the same thing occasionally and i am waiting for a chance to get the throttle body back off and get the gasket changed to see if that helps. let me know what you think...