Rough Idle, Cold Start?

[warrioralumni08]

Ok I know, this has been covered, and beat to death alot and most everyone is going to say IAC. So, with that said, I checked for codes, one was because of no egr and the other, was because of no cats. My IAC is pretty new, no more then 500 miles on rebuild, so I don't think that's what it is. Unplugged the mass air, car started running rough, so that's not it. Put a load test on the battery, it passed. What else could be causing this? I don't want to sit here, throwing parts at it, that I dont need. Spark plugs and coolant temp sensor, are also new. It cranks and idles very rough, at about 500, and then dies, if you try to give it gas it will bog down and die also. Start up a second time, and it runs smooth, and it's a Gen 1. I dont want to think its the IAC, since it's new, but it could be.

 

[Hot*Mk8]

Fuel filter?

 

[mistermaclincoln]

You didn't get an O2 code so I would check Air intake temp sensor and check the altenator for a bad regulator. Check the fuel pressure also. This is how my issue started.

 

[GMAN]

First I would check for vacuum leaks. A lot of problems usually leads to to a vacuum leak of some sort. There are a lot of places for air to get in. Also since you have a gen 1, did you double check the gasket between the IAC? What about the throttlebody. It can be getting too much air there as well. When it warms up everything has expanded so no more leak.