Shuttering at acceleration

[needalotofhelp]

Hi I've read a lot of the post and have seen some similiar problems as mine,but not quite the same. Here's my problem:

When driving down the road as I press on the gas, my car shutters something terrible. If I let off the gas for a second or put more pressure on the gas peddle the shuttering stops. You can feel and hear something rumbling under the gas peddle on the front underside of the car. When it acts this way while idling it runs really rough like its not running on all cylinders. On my way to work this morning, it was 40 degrees out and I had to be off the gas on the gas the whole way to work, when I stopped at a stop light the engine was running rough, almost like it was going to stall. At lunchtime, I went out to drive it around so I could describe how it runs...well, it ran smooth as silk. No shuttering going down the road and at stop signs it purred like a kitten. The only thing I noticed was when I first started it and stopped at a stop sign, the engine kinda hiccupped, just once and then it was fine. It is now 75 degrees out, and I've never associated the problem with the temperature but the problem, but It will run awful for a while and then seem to work itself out, much like today.

Anyone else having this problem? If anyone has any ideas as to what could be causing this, I would greatly appreciate some insight.

[richtazz]

Try a tune-up first if it's been a while. Use quality plugs like AC-Delco or Autolite, and avoid Bosch, they are junk. Same with wires, don't go cheapo. Check and change if necessary, the PCV valve, air and fuel filters. Let us know if this helps.

[needalotofhelp]

Got a tune up, replaced all the plugs, wires, air filter, fuel filter..checked the vacume hoses...still have the same problem..what are your thoughts on the Catalytic converter?

[richtazz]

What year is your car and what engine?

[needalotofhelp]

92 3.1 v6

[needalotofhelp]

I was wrong about the temperature too...I did the same thing yesterday drove to work with the car running really rough, parked it went out at lunchtime drove it around (it was 75 here) and it was still running really rough, didn't smooth out this time. It's very intermittent....

[richtazz]

You'll have to do a back pressure test to rule out the catalytic converter or an exhaust restriction. What brand of plugs and wires did you use? Just because they are new, doesn't mean they're good, especially if they are off-brand cheapo stuff. If I had a dollar for everytime I've heard, "It can't be that, I just replaced it", I could retire. It could also be a fuel injector or two going south on you. They will act up intermittently when they first start to go.

[millerwl71]

CV joint? Mine does the same thing.

[needalotofhelp]

Well, I did have a ball joint break, it also busted the axle and we had all that fixed on the front end and it didn't make a difference...not sure if the cv joint was replaced when we did all that work but I'll find out

[Supergumby]

If you can get it to do it at an idle, let it sit there for a few minutes 'doing it'.

Now shut off the engine, let it cool a bit, and pull the front three plugs. One of them should be uglier than the other two. Which ever one it is, replace that coil.

The cylinders across the front are (from left to right) 2, 4, & 6. The three coils are (from left to right, looking at the front of the motor) 1-4, 3-6, and 2-5.

If the center plug is ugly (wet, dark, furry), that is cylinder number 4, so then replace the left coil.

Clear as mud?

[needalotofhelp]

Sounds good to me...I'll pass this on to my husband and see if he can do it....thanks!