So I have a 95 z28 convertible. Now my problems is this: when I bought the car, it ran kinda sluggish and it couldn't do a burnout for the life of it. I checked the plugs and saw they weren't the factory brand and they weren't properly gapped. So I buy new plugs and wires and install them with the proper gap. Now right when I started it up after that it seemed to have a rough idle. It would run and then start jumping when the engine warmed. I've noticed it jumps in a pattern, after a little while. Kinda like a small misfire, and when it does, the lights in the car dim a little, and the batter gauge, oil pressure and Rpm's bounce around a little bit and the car shakes. Not violently but noticeable enough to be annoying. It doesent jump or surge when you accelerate or have higher Rpm's. It struggles a bit at first when you push the pedal but not much. I have a new fuel pump, MAF sensor, fuel filter, pcv valve, checked the tps and the IAC valve. And it still does it. This was almost 13000 miles ago and it has only gotten a little worse. It drives and runs well, I seafoamed the car recently and bench cleaned the throttle body and it has more horses but still idles funny. I'm lost. Could it be the optispark? I'd think it would get worse the more I drove it. Can I test that? Or is it as simple as bad wires or a mis-gapped plug?

 

The alternator, ICM and coil all tested out fine as well, and the check winging light comes on for a few seconds every once in a while when I'm driving.

 

What year is it? If it is 96-97 then you should be able to pull codes from the memory to determine why the light comes on and off. This kinda to me sounds like a plugged cat, if the car was 96+ the computer would tell you if the cat was bad but the older ones dont. Sluggish and a slight miss but no direct codes from the ignition system or fuel system sounds like Cat, could also be clogged injectors but that usually pulls up a system too lean code.

Massey

 

It's a 95

 

Defidently look at the Cats

Massey

 

Nope, checked the cat. It's fine. Any other ideas people?

 

how did you "check" the cats???

 

if its effecting the lights then start checking wires for damage, corrosion or looseness. like the alternator wires. also you have three main grounds on the engine one on the side of the block by the starter, one at the front of the motor on the passenger side of the block under the belt tensioner, one at the front of the motor on the driver side of the block under the coil bracket. check all these grounds for damage and or corrosion and for looseness. take your battery cables lose and wire brush the battery terminals and the cable ends. take the wires lose in the power junction box (small red plastic box on passenger side fenderwell) and clean them as well. there is also a ground junction there, clean them too and check for damage or corrosion. theres a main ground inside the car too and im tryin to remember where, im thinkin its on the steering column,,,, at least in that area under the dash. ill have to look in my book. best investment you can make is picking up a factory service manual for your yr camaro. on a darker note,,, how old is the opti and what kind is it?

 

I'm relatively sure it's factory....sigh. But I'll start with the wiring and give an update

 

Inside the car there are 2 grounds under the dash. Both grounds are behind the kick panels one on each side of the car.

Massey