So on my way home from school just now, I came to a stoplight and noticed the idle was VERY rough for some reason. It might be me, but there seems to be a little bit of lag when I accelerate. When you get on the throttle, there's black smoke coming from the tailpipes, and I smell some fuel in the air, though nothing's visibly dripping to the ground. Like I said, the car has trouble starting even when I crank it a good deal. A friend told me I should get my spark plugs checked. (They're the originals on my '94 Z28 with a little over 60,000 miles now.) Anyone else have an educated guess as to what might be wrong?

 

as for the idle and lack of power i'd think that your sparkies and even wires could use a changing, however i'm not sure about the black smoke. Either way you should change your sparks, one of them might be shot even, depends on how you drive it and if your like me you definetly should change it.

 

How much of black smoke are we talking about here? Like a james bond smoke screen? So what's your driving style and what else have you noticed along with the smoke? Any knocking sounds? As of right now...is it still idling crappy & smoking? I had a dodge that did the same you described and it was from bad Cats..

 

The black smoke comes out in gobs if you rev the engine. Sitting in place at idle, it builds a cloud behind my car after about half a minute. Accelerating from one of the stoplights, the engine almost died on me before I started moving! I should also add, it takes about 5-10 cranks to get the engine started now. I've taken the car to the track for about 30 passes total, but that's the only time I go WOT. The oil level's good, no leaks, and the engine temp is right below 200. The exhaust sounds VERY choppy at idle, and even a little bit while I'm getting the car up to speed.

 

Sounds like either a bad blug or a bad wire (IE: one cylinder not firing)

 

This is where I invested in a few testing equipment on my $$ eating 96. I would probably go to an Autopart store and buy a cylinder pressure tester. This should be about $15-30 bucks. Check each cylinder and follow the directions. Thought that may be an option, good investment actually.

 

I'm trying to narrow down the list, so can I rule out a bad cat? I'm figuring that probably wouldn't cause the starting problems, but please correct me if I'm wrong.

 

anyone?

 

Change plugs and wires. Best bet. If you are not sure, pull any plug (which is easiest) and inspect it - I think you'll decide to change them after it