RB20 idle climbs on startup

[zdonner]

I'm going to be picking up a couple of 240's this weekend, well one is an 89 Coupe with a RB20DET in it and when you start the car the rpm's climb slowly rather than "*Click* Vroom*" if you will. it's a slow climb to idle.

Also the turbo is whining pretty bad, sounds kind of like a low pitch supercharger. Bearings? I've not heard a turbo make a sound like that, it is the stock whatever on the RB20, oh and it's open DP.

Thanks for the help.


Modified by zdonner at 2:20 PM 11/29/2006

[zdonner]

Anybody have any input? I've seen this sort of thing before but I never found out what was wrong.

[digzsublime]

Not sure about the idle but could be 1. Cold start wire not hooked up or 2. bad IACV. Just a couple of ideas. As far as the turbo goes, it could be going bad but, running open down pipe will exagerate the whine from the turbo making it sound way worse than it may be. Good luck on your new purchase. Hope all goes well.

[zdonner]

Thanks, he had a friend of his check it out which I'm told is knowledgeable, but I'm taking it with a grain of salt until I can look at it. But he said its wiring they traced back to the ECU and the wiring looks terrible. The Turbo that's what I was thinking this friend of his oh I'm going to add real quickly supposedly works a reputable shop in SC I should ask the name, but anyway he says it sounds like the turbo is going out, now I've heard the car start up but it was over the phone and I didn't hear any noises I wouldn't expect from open DP. He's bringing both cars down on a roll back this Sunday morning so I'll find out if it's bad or not.

Thanks for the input I was starting to wonder if I'd hear anything I'll check the IACV and I'll definately get to try a VERY cold start (For around here anyway) when it gets here. Gives me a little more to think about.

[Carl H]

tps isnt set right, causes erratic idling and a poor/hunting cold start.

[mugengsr]

how can you come to that exact problem ? tps not being set correct will cause a few other problems such as nasty bucking problems and crap like that but as for idle i have not seen it.... im putting my money on .. acc valve needs cleaning(back of the plenum) also you could clean the iacv as well its a bugger to get at as its down by the injectors but it helped with my idle when i had i had problems ... doing these things have helped some cars but it just made my idle better ..

slow rise in revs till its at normal idle .. mine has been like that since i got my skyline and i have heard countless others with the same problem .. my tps it smack on

[digzsublime]

I believe you've got the location of those 2 valves backwards. IACV is on the back of the plenum. AAC is the one that is by the injectors below the throttle body.

Carl H knows his shizlle. If he says the TPS could be the problem, then I'd check it. Base timing could also be an issue that I think could cause this. My RB20 fires right up to 1600-1800 rpm then goes back down to normal idle.