Idle Problems. Brick wall at 3K.

[Kingtal0n]

1991 5.0HO 5 Speed.
Problem:
-Cold Start: Fires, revvs up, then dies unless I give throttle.
-After finnaly starts up, idle goes UP then DOWN then UP then DOWN for about 5 minutes.
-After warm up: Starts and idles Fine at 800 RPMS. <b> Pulls 8" of vacuum and has Lopey idle</b>.
-POOR throttle response. I barelly TOUCH the gas and the engine revs WAY UP then comes back down slowly.
-seems to have plenty of torque. I can put it in 3rd gear at 5 MPH and pull out. does not buck or kick back under load at low RPMS.
-After about 3,000 RPms it loses power. brick wall. it will still climb, but REALLY slow. much slower than stock.

replaced:
IAC, TPS, Injectors, MAF, O2, Intake/plenum Gaskets, Computer was rebuilt.

Other info:
Engine is supposed to be stock. sounds like it has a HUGE cam though.
Pulls 18" of vacuum on highway, Gets 10 MPG, poor throttle response, 150~PSI cylinder pressure tested, 5 Speed just installed (auto blew up, been doing this since I got it though), already messed with TPS and IAC stuff. Changed everything I could think of, out of options. I disconnected every vacuum line i could think to see if it was a leak but to no avail.

????

[sn95gt19]

it sounds like a bad mass air to me, but you said that you replaced that, the only other thing that i can think of is a bad coil, that only relates to part of your problem though. did you replace the mass air with a new one or a used one, to me it sounds like your mass air is still the problem.

i have had the same problem with 3 of my stangs (3000=dead) and on all of them it turned out to be the mass air

good luck

[Kingtal0n]

It is a USED MAF i replaced it with from another stang, Im goina try another one tommarow i suppose. thanks for the reply.