Very Weird idle on cold startup

[Ipsd]

I have this problem with my 84 turbo coupe. On cold startup it starts and goes to high idle @2000 Rpm then suddenly it cuts to 1000@ and sounds like it is running on 2 cyclinders. If you give it gas it wraps but very very very slowly. I can even build boost at 1200RPM when this happens. When the car does get up to temp every thing is fine. I've tried a different Dizzy and TFI, Tried a second VAM, Also the Timing is @ 10*BTDC, I'm also running the 88 intake with intercooler, I have the tps set @ .97 I also have a PC1 ECU and the brown top injectors. Need any more info let me know. And thanx in advance

[jayG]

Try cleaning the IAC.

[NavySVO]

your ECT could be the problem. It will feed the EEC the engine temp for fuel scheduling, especially important during cold starts.

[Ipsd]

I put a new ECT in it and the same thing. Start it up and it goes to 500RPM idle and will barely idle at all. I've also tried a different VAM, new Dizzy with Motorcraft TFI. Gonna put in some new plugs just to check that.

[NavySVO]

You should make sure the car has had a proper tune up, with Motorcraft parts. Plugs gapped around .034".
Also as Jay G said, remove and clean the IAC valve with fuel injector spray cleaner. You would be surprised how much crap will come out of there.
Does it just do it on cold start-up?
Did it just start this all of a sudden?

[Ipsd]

Yep it started all of a sudden. I have put in a new cap,rotor, TFI, and plugs. It just started one moring i started it up and it wnet from 2000RPM to 500 RPM and wont warp up very fast and i can build boost sitting still. The old plugs were very black and looked to be toast.

[Ipsd]

It's running so ruff that by the time I get it to 1000RPM I'm in to boost. And that is in the shop sitting still clucth in or in netrual. This happen first for a couple days but would only happen for like a min or so then go back to normal. Then last mon I spent all day digging aroung and fixing things That might have caused this. At about 1pm I started it up and Everything was finr prefect idle and runnin like a raped Ape. Ran the car for about an hour and other than the bucking under boost everything was great. Then Tuesday morning I went to start it up and Popped right of and went to high idle for a second or so then dropped to about 500rpm. So tuesday night after work I replaced the ECT with a new ford one even though the one in there has less the 5000mi on it. I also changed the plugs. Still the same thing. I haven't messed with the IAC but the ine that is one there was just cleaned only a month ago when the Idle was sticking at 2000 and I turned out to be the TFI. Any how This is drivng me nuts. Didn't work on it today after work. Just brunt on cars for the day after sellin parts all day.

[GAboySVO]

You might want to reset your TPS. 0.97 will work, but it sems a little high. Set it between 0.90 - 0.92.

Before you crank it when cold, remove the spout. If the idel doesn't start jumping around on you, then plug it back in and see what happens. Then do what Mike said about the checking your timing.