mako350Z28

Just like the title says. It idles a bit rough and under any acceleration, which the car isn't doing so well at right now, the car shakes like crazy.

Besides plugs, wires, ect. what could the problem be?

aklim

Distributor cap and rotor. Ignition coil. Ignition module.

Take an inductive timing light and hook it onto each of the wires and see if the RPM it reads is constant. It should be or that low one is bad.

BTW, you could also have a bad cylinder.

IROCBeerBeer

broken motor mount/

mako350Z28

Checked those. The problem was a bad sparkplug wire on the driver's side. Sucks but at least it was something cheap and easy.

mako350Z28

Drove to work today after I replaced the wire and it started doing it again about 5 miles down the road.

Just out of curiosity, wouldn't a bad coil affect all of the cylinders instead of just one?

aklim

Of course it would but if it gives a weak spark, some cylinder might seem to miss. Check the quality of the spark at night. Must be a strong blue spark.

mako350Z28

Well, I changed the coil this morning after checking it last night but that still wasn't it even though I can feel a bit of improvement. I am taking off from work tomorrow and a freind of mine is coming over with a scanner and we are going to work on it together.

I think that I an going to do a few other things to it while I am at it.

Marc 85Z28

A scanner will not diagnose ignition problems on that car. And it sounds like you have an ignition problem. Normally I don't suggest throwing parts at a car. But with a misfire on an older SBC your best bet is to do a full ignition tune up. Cap, rotor, plugs, wires, coil (if questionable), and set timing. Its cheap and easy preventative maintenance.

Ville H. Valo

I had the EXACT same problem less than a week ago, i changed all of the plugs, wires, dis cap and rotor and my car runs like a champ again. you describe the shakeyness, i had the same thing, the higher the speed/rpm the worse. take a look at your bat. gauge and see if it fluxs at all during idle.