02 GRAND AM HELP!Car jerks during acceleration

I need help my car keeps jerking while im accelerating. I just tried changing the plugs and wires to see if that would help. It didnt. I dont know what else to do. anyone got any suggestions about what it might be

No idea if this will help, but fuel injector cleaner and a new fuel filter are what I'm going to try to get a more uniform acceleration. My car just rolled over 170k and it hasn't gotten a new fuel filter since at least 123k, if ever.

Listen to xeroinfinity and others tho because they know a lot more than I do :)

What engine do you have?

Check for codes and or look for vacuum leaks.



2002 Grand AM SE with 3.4

Your engine size would help........

Could be fuel related, I would try changing the fuel filter if it hasnt been chenged the last 10-12k miles.

Using a fuel injection cleaner regularly will help keep your fuel system cleaner. The injectors in these cars are bad about getting clogged/dirty and causing misfires.

The injector wires are also known to get breaks in them up on the intake. IMO its caused by carelessness when changing the lower intake gaskets, so if you hav had LI work done migth check those.

sorry, its a six clinder. I put some fuel injector cleaner in a few days ago, Ill wait a little longer to see if it helps. If not Ill try changing the fuel filter. Ill let you know. Thanks.

Still having problems! I changed my fuel filter and still no luck. Any other ideas of what might be my problem?

IF the plugs and wires are good, I'd say its still your injectors.
You can buy or rent a Noid light to test the injectors to make sure they are pulsing correctly.

Give the injector cleanr a while to work, it doesnt work over night.

Aslo Check for vacum leaks , around the intake manifold and air intake tube.

I had this problem with 2001 while it was still in warrenty. The dealer said that there was a service bulletin on this and the software needed to be updated. It helped a lot, but wasn't 100%.

It could be your MAF. Mine was starting to act up. Your engine light my not even be on and it still could be the MAF. It helped a lot, but its still doing it. I'm going to replace the IAC next. I have 98 Am GT 3.1 Liter. i thought for sure it would solve the problems...but it didn't. I wish the service engine light would turn on, it would make diagnosing the problem that much easier. I hope this helps a little. I'm still trying to figure mine out. :) But I love my car and it better not crap out. I still have 43 payments left LOL

It could be your MAF. Mine was starting to act up. Your engine light my not even be on and it still could be the MAF. It helped a lot, but its still doing it. I'm going to replace the IAC next. I have 98 Am GT 3.1 Liter. i thought for sure it would solve the problems...but it didn't. I wish the service engine light would turn on, it would make diagnosing the problem that much easier. I hope this helps a little. I'm still trying to figure mine out. :) But I love my car and it better not crap out. I still have 43 payments left LOL

SO you are saying you just replaced the MAF and did test it first ? :disappoin

The MAF for an 01' run around $350

Cleaning the IAC's port it resides in can help idle, but not really acceleration . It can be tested too.
The IAC on an 01' Runs high also, around $100

Why waste money on things that are not bad :shakehead

Even though thiers No SES light on doesnt mean thiers no codes stored for your troubles, get it scanned!

Good Luck

I have found over the years that when the engine starts getting a little stumbly or jerky to just take it out on a quiet road and stand on it a bit and blow the carbon out. Is worth a try and wont cost anything as long as John Law isnt hiding in the bushes.........

I have found over the years that when the engine starts getting a little stumbly or jerky to just take it out on a quiet road and stand on it a bit and blow the carbon out. Is worth a try and wont cost anything as long as John Law isnt hiding in the bushes.........

Some times,
with some premium fuel and some good injector cleaner in the tank, it can help loosen clogged injectors and blow out some of the cobwebs.

SO you are saying you just replaced the MAF and did test it first ? :disappoin

The MAF for an 01' run around $350

Cleaning the IAC's port it resides in can help idle, but not really acceleration . It can be tested too.
The IAC on an 01' Runs high also, around $100

Why waste money on things that are not bad :shakehead

Even though thiers No SES light on doesnt mean thiers no codes stored for your troubles, get it scanned!

Good Luck



Well yeah I went out and bought one for my 98 GA GT and it was a remanufactured one from Cardone and it was 98 bux, however, it didnt fix the problem, and I replaced the IAC and it still didnt fix the problem. I'll accelarte and it like sounds like its gonna die and it doesnt want to go...you push the gas and it just revs at the same speed and its really annoying...it jerks horrbile sometimes when it has its problem and then it eventually clears up and amazing power comes back to her... but it does it way more now then it ever did so im still clueless...my dad said it must be an injector...everything else with the car is fine just this little hickup. Any thoughts anyone.

Should not have skimped out on the IAC. :nono:

The remanufactured one probly isnt the best;
or you didnt adjust it properly;
or the passages that pull air in/out are clogged.

If its something electrical, you can ALWAYS test those parts to make sure they are bad, instead of wasting money .

But from what you discribe mlasnoski, you could have other issues.
Water in the fuel, clogged fuel filter, and as you said injector(s).

BTW- Just because you dont see any engine lights on, doesnt mean that thiers not any codes. AS if the light is ignored long enough the bulb can burn out and you wouldnt know untill you checked.

It is recomended that your fuel filter be changed every 30-40k miles, and GM recomends you get the fuel sys. cleaned also. ALso get the fuel pressure checked.

I'll second Xero on the fuel pressure. Since you said that sometimes the power comes back I would tend to believe the injectors are clean. A buddy had a '98 Buick with the 3.8 and his FP was intermittant and acted similar to what you describe.

Thanks for the help. Yeah it spits and sputters and just chokes up to speed and then after a little bit of run time or after it does its thing its fine. I can smash on it and it has the balls i expect it to have. The one morning I thought i wasnt even gonna get anywhere she was choking so bad. My grand prix had the exact same engine and I never once had a problem with that. How do I go about checking the fuel pressure? Ive been running fuel injector cleaner in it a lot still has this issue. I buy the expensive fuel injector cleaner. A guy from my church said it could be a gas temperature sensor on the engine block? is there such a thing and could that be possible. I also notice that I get horrible gas mileage its the 3.1 liter i get about 18 mpg i do live in the city but still i should get at least 22 mpg jeepers. I still owe 4,000 bux on her i really dont want to be throwing tons of money away already. She only has 85,000 miles. Thanks for the help....

I've never heard of a "gas temperature" sensor. On the fuel rail you'll find a schader valve like the one on your wheel, you can hook a fuel pressure gauge up to this and monitor the pressure.

what should the pressure be at? if and once i find this schader valve. :) if the pressure is down what then do I diagnoise to fix the pressure problem. I already had the spark plugs changed, there's a new fuel filter in since october. not sure what to do once i find the pressure thingy.

The shradder valve is located on the pass side of your enigne.
Between the alternator and power steering pump.

Fuel pressure should be 40-47 PSI.
Most parts stores rent or sell fuel testing gauges relativly cheap.

Also GM does recomend that the fuel system be cleaned once in a while.

You can buy the Tool/device but they are pricey!
Around $300-450 with the cleaner.
It attaches to the Shrader valve and cleans the rails and injectors very well.
These injectors are prone to clog/fail :grinyes:

Well because I'm no mechanic i sucked it up and brought it in to get looked at. They hooked the fuel pressure gague up to it and they only got it to make it in the shop act up a few times but the gague he said showed 20 psi for fuel pressure...he said that was way below specs. although he said it was holding steady at the right psi for the most part. He wants to keep it over night and check it in the morning with a cold start. He's thinking its the fuel pump...great i looked on Advance Auto Parts website to see how much one is...those suckers aren't cheap $277 bux for a decent one :eek: .. so i'm probably looking at a 400 repair bill. :banghead: hopefully i'll get better gas mileage...rather then 18mpg. he said labor would probably be 165 bux. I have this awesome loaner car :screwy: ...it sucks. I will keep you posted on what it ends up being and how much :grinyes: thanks so much to all you mechanically inclined people. I dont know much.

Well with 20psi on the FP , they should have been able to tell Right then if it was the fuel pressure regulator or the fuel pump :shakehead

Good Luck!

He said it wasn't the fuel pressure regulator...he said he took the vaccum hose off and it went back up to 40 psi..but he wasn't positive he wanted to some more testing with the gague tomorrow morning.

Well it def was the fuel pump...they got it to act up today. But the bad news it was def a little pricer than I anticipated. The total job is going to set me back $520 bux. :shakehead there goes my tax refund. but i guess i should make up for it in the gas mileage I lost haha. I only ever got 18 mpg.! Thanks to everyone that gave me thoughts on why it was doing it. Everything that I replaced could have been the problem. Without that Service Engine Soon Light...its hard to even determine what is wrong. Thanks again everyone! You all are very helpful.