Car running rough at low rpm
 

Im having a problem with my Z28 that just started this morning. Its like it runs real jerky, like the whole car shakes at low rpm's. It feels like a car thats starting to die,where the car starts shaking. The rpm gauge is reading fine. It's not fluxuating at all,no service engine lights,and oil pressure reads fine. It does it just when im coming to a stop. I tryed to explain the best i could. Can anyone help? Forgot to mention, i have a small oil leak from the valve cover ont the passenger side. Is it possible when my dad put some oil in,he put in too much? Would that cause the problem?

Have you driven through any large puddles lately or changed your waterpump or thermostat? Can you hear any arcing? You could have an intermittent misfire condition, it would show the same symptoms you are describing. Also, you have a 94, which means non-vented opti-spark. Try making some WOT runs and see if the car jerks at all or missed during acceleration. You could have a burned or just old spark plug wire that likes to arc in high humidity.

sounds like your down a cylinder. What I would check is your while the car is running disconnect one at a time each injector to see which cylinder is not firing, if the engine doesn't change its idle you know then its that cylinder. then all you have to rule out is either spark or fuel issue

It runs fine when i give it some throttle. If it was misfiring wouldn't i get a service engine light? The plugs and wires were just changed about 5000 miles ago. It doesnt seem to have a power loss associated with being down a cylinder. I know the exhaust doesnt sound right either. It isnt a smooth sounding rumble like it was. Its the wierdest thing.

well if the exhaust sounds different then mabe its the catalytic converter.

The OBD-I cars did not have misfire detection, so you wouldn't get an SES light if that was the case. You said the exhaust doesn't sound the same... are you sure there aren't any exhaust leaks, especially any before the 02 sensors?

It almost feels like one of the wires is fried but if that was the case wouldnt my car stall out? And it definetly is down on power.

Your missing on a cylinder..

wouldnt it be stalling out if i was down a cylinder?

On a v8 losing 1 cylinder? not likely, you still have 7 other cylinders firing just fine.

Nope. I had one plug wire not on a spark plug once and the engine ran fine idling, as soon as i got on it a bit though it was easily noticable something was wrong.

Sorry to bring up an old thread but i got my car fixed. It was a fried #6 plug wire. Pep-Boys did my plugs and wires last time and left it too close to the exhaust manifold. It cost me 270 dollars to get it fixed. I just wanted to replace the #6 wire since i just had them changed 6 month's ago. I guess he didnt hear me and i got taxed. But it runs as good as ever now.

Re: Car running rough at low rpm
 

I have a 92 RS with the 3.1 v6 and it is doing the same thing, right around 15 rpms is is really rough and shakes the whole car. It does almost feel and sound like im missing a cylinder, but at a higher rpm it sounds just fine. Im hoping its just plugs and wires but i havn't checked if its something more serious id really like to know