My 85 IROC is running rough when I first start it up. After running for a few minutes, it smooths out. I can even feel it through the gas pedal. It seems like it's running on 7 cylinders. Any suggestions on what might be going on?

 

maybe it's running on 7 cylinders since you said that's what it acts like. have you tried trouble shooting to see if you do have a dead hole? WAG but i think i'd look at the choke.

 

I think it could be associated with the choke, it seems like it could also be something dealing with fuel delivery. When my car was just a month old, it fouled a couple of the injectors and utlimately they all had to be replaced. The symptoms it has now are somewhat similar to how it was performing with a fouled injector. The one difference here is that the problem goes away as the engine reaches normal operating temps.

How do I troubleshoot the choke to try and rule that out?

 

The tuned port injection setup doesn't use a choke.

Maybe CTS related?

 

Does it only stumble around only when you first start it up?


I had leaky fuel injectors and when id start the car, it would stumble for the first 10 seconds until it cleaned itself out.

 

Okay, I'm not sure what CTS is. Could you decipher that for me?

Secondly, sometimes it stumbles for just a few seconds, other times, it runs like that for a few miles before straightening itself out.

 

CTS = Coolant temperature sensor.

https://www.thirdgen.org/techbb2/att...postid=2036300

 

Well I pulled the plugs and they all looked normal with the exception of the #1 cylinder. It was wet and smelled like gas. I haven't even started it up today. I shut it off after getting home yesterday after work, around 4:30 p.m. I think that this may be the source of my problem. Now, what could be causing this?

I replaced the CTS a couple of years ago.

 

Sounds like a leaky injector on #1. Get a pressure guage, prime the fuel system, and see if the pressure leaks down a little at a time until 0 psi watching the guage... it make take a few minutes, but that would be my guess for the gas...