OlderThanMe Posted December 18, 2006 Share Posted December 18, 2006 Car: 1986 Porsche 944 Turbo Problem: idles at 2400 RPMs Well I spent most of the day today helping my dad put all the EFI stuff and intake back on the 944t. It had a problem of idling at 2000-2400ish RPMs and so we got a new idle control valve (old one was broken) and another part and put them on. After all that we fired the car back up after a month or so and it idled at 1200 for about 30 seconds and then it doubled that. This "idle control valve" has the hose (just installed a new ones today) from the wastegate connected to it, a hose from just before the turbo on the intake(vacuum side), and a hose after the turbo (pressure side) on the intake side connected to it. It also has a 2 wire connector attached to it. This piece was physically broken into like 12 pieces so it got replaced. The car still idles really high. One thing I noticed was that two of the connector seats were slightly cracked but not too bad. The car idled really smooth at 1200 at first for 30 seconds (cold weather idle plus it normally idles at 1000) and then it raised up to 2400!?!? This is getting really frustrating. Can anyone help me with this problem? Quote Link to comment Share on other sites More sharing options...
veritech-z Posted December 18, 2006 Share Posted December 18, 2006 Is your throttle sticky at all or not adjusted correctly? I know you just gave it the hot rod powder coat treatment, so it's probably pretty clean, right? Is that a mass airflow car, or a map sensor car? If it's a mass airflow car, could you possibly have a leak in your turbo intake plumbing after the sensor? Maybe a torn boot or something? Quote Link to comment Share on other sites More sharing options...
Sparks280zt Posted December 18, 2006 Share Posted December 18, 2006 Easiest way to solve this problem is: www.renegadehybrids.com Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted December 18, 2006 Author Share Posted December 18, 2006 map sensor? I think? It has a regular throttle body (not tbi) It had this problem before the powdercoating... The throttle is fine... There could be a leak somewhere after the turbo but I doubt it. I am thinking it is a vacuum leak somewhere. I'll get some pics tomorrow. Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted December 18, 2006 Share Posted December 18, 2006 um.. maybe the idle air valve open too much?! Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted December 18, 2006 Author Share Posted December 18, 2006 actually...Just talked to my dad about this thing... We replaced the fuel enrichment valve(for boost). Not the idle air control valve... I'll check that tomorrow morning. Thanks Prox... Quote Link to comment Share on other sites More sharing options...
Gollum Posted December 18, 2006 Share Posted December 18, 2006 A honda B16 I was working on a year ago would idle at 3-4k... Now THAT's a high idle. It was almost like having a stall... That engine's probly ended up being a combination of a vacuum leak in the TB and a screwed up ECU. Quote Link to comment Share on other sites More sharing options...
GrommitZ Posted December 18, 2006 Share Posted December 18, 2006 Somehow, the ICV has to bypass air around the throttle plate, into the intake manifold. Either hose before or after the turbo might be the source of air for the intake. You didn't mention a passage for air into the intake manifold. If the ICV doesn't have an internal air passage, I would guess that intake manifold line may be connected improperly. The 2 wire connector probably activates an ICV solenoid that either allows air directly in to the intake manifold, or operates a vacuum valve that lets in air into the intake manifold(like the 280zxt). See what happens when you disconnect the electrical connector. Also see how the air can flow through the ICV when it turned on vs. off. You mentioned one line leads to the wastegate actuator. Is there a tee to the intake manifold. All the manual wastegates I'm aware of operate off positive pressure from the intake manifold(under boost). Hope this helps. Quote Link to comment Share on other sites More sharing options...
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