Why would a car sputter when you accelerate and idle rough?

Answer 1

Nobody ever mentions an egr valve replacement..this is common in gmc vehicles...Rough idle,stalling, ignition starting trouble all relate to the egr valve sticking...

Your problem is a misfire. You need to do a misfire diagnosis and then correct the cause of the misfire. If you have allowed the misfire to continue for too long, engine damage may have occurred, but otherwise correcting the cause of the misfire should set everything right.

AnswerUnfortunately it could be a number of things causing rough idle and hesitation. It sounds like the engine might be confused about how much gas and air it is getting which might mean it needs a new oxygen sensor (EMISSION) or throttle position sensor. Start with the easy maintenance items like spark plug wires, air filter, and fuel filter if they have not been replaced recently. A bad spark plug wire may only occasionally short out and cause these problems. Try looking under the hood in the dark with the engine running and see if you see any electrical arcing around the spark plug wires or just go ahead and replace them if they are old. www.RockAuto.com AnswerIt might just be a clogged fuel line/injector/ or pump, try to put some fuel cleaner in tank the next time you fill it up and see if that helps. AnswerThere are about a million and a half things that can cause this some minor, and some quite serious. First off I would have to agree with both of the previous answers but I would also have to check out a couple more things such as the MAP censor,and the o2 censor. Also adding a can of "Sea-foam" to your gas really couldn't hurt either. Good luck AnswerCan low idle speed cause this too? AnswerMy car idled rough onced and shook horribly through the whole car when I accelerated or was just pressing the gas. When I let go it would go away for a sec then come back. I put fuel system cleaners in a few times and that didn't help. After I had replaced my spark plugs it still was rough.

I found later that there was a mis-alignment(TWO PIPES WERE NOT CONNECTED) in my exhaust pipes and the flow of exhaust was interrupted. Which was the cause of the shaking.

So check you exhaust for a funny noise that could be an interruption in the exhaust system. In my case some of the exhaust was leaving toward the engine with a powerful force and shook the car where the engine roughly is, which lead me to think it was the engine.

Answerspark plug fouled or coil pack bad AnswerAcura integra ls 1994. my problem was the spark plug wires they looked ok, but were wore out.

Answer

could be coil pack, head gasket, fuel pump, or bad injector

RockAuto gave the most extensive answer, sorry, but you have to start with the basic's. A good way to check your EGR : start the enging, stick your finger under the EGR; you should be able to feel the diaphragm. Tap the throttle a few times. If the diaphragm moves, it's probably good. Secondly, nobody mentioned vaccum. Fill a spray bottle with water and spray all around the intake. If the engine idle changes, the problem is an intake gasket. Your idle will be rough, then smooth out. Check all your vaccum lines too! These are all things you can check without doing anything to the motor.

You may consider buying a scanner and pulling your codes. This will tell you the circuit your problems are in.

If you pull the o2 sensor, sometimes they are clogged and you can clean it and put it back in. But for the trouble of raising the hood, replace it while you are there!

Answer

I have a '99 Hond a Civic LX and my car was also idling rough and 'sputtering'. The mechanic used some 'Seafoam' on it and that helped a tiny bit. Then he said it might be the a/c compressor clutch. But compressors usually last a long time. I also noticed it only sputtered when my A/C was on. So the problem was with the A/C. I tried adding a little freon thinking it was low since it had never been recharged in 115k miles. This did little to nothing. I added some PAG oil and this helped more. The A/C would get cold for a few minutes and then heat up and go back to sputtering. So I had a free A/C check done on it and it was the condenser fan assembly. Apparently the motors go bad after awhile. It was getting stuck and not kicking on and that was what the sputtering was from. So they hit it with a hammer and it kicked right on and now it is super cold. So whenever the motor on the condenser fan is completely shot I will buy a new one but for now it is fine and working. By the way, you should never try to add freon or PAG oil yourself because then the levels are off and might put too much pressure on the A/C system. My next step is to have it evacuated and recharged and I'm good to go!