Annoying Rb25det..

[XxNinjaxX]

ok ive brought a r33 series1, i knew it had leaks that needed to be fixed but i was willing to show her some TLC, brought her home ran great, no real problems apart from rich fumes which ive heard to be normal for most skylines. anyway ive had her a few months now and ive noticed on cold start she'l start at 1000rpm and by herself she'l start to fluctuate from 1000/500/1000/500rpm, its not causing any damage but it is annoying since ive just brought her, any ideas on whats causing it? cheers

[TRB-001]

firstly the "rich fumes" IS NOT normal for any car, let alone a skyline.... if its pumping out black smoke there is a problem sumwhere and its running rich.... most commonly if sumone has mucked around with an intercooler setup ull have an air leave somewhere....

anyway

check and clean your IAC motor.....

[Benzino33]

ok ive brought a r33 series1, i knew it had leaks that needed to be fixed but i was willing to show her some TLC, brought her home ran great, no real problems apart from rich fumes which ive heard to be normal for most skylines. anyway ive had her a few months now and ive noticed on cold start she'l start at 1000rpm and by herself she'l start to fluctuate from 1000/500/1000/500rpm, its not causing any damage but it is annoying since ive just brought her, any ideas on whats causing it? cheers

Im all too farmiliar with this lol.

Well as far as it idleing at 1000rpms, is completely normal till the thermostat closes, then it goes down to 750-800 rpm.

But the 1000 to 500 is kinda confusing..might be a vacuum leak somewhere, check all your hoses.

check or clean your afm as well,,might just be screwing up a bit. Yeah and IAC valve may just be playing up wen it's cold, check and clean it out

Hope that helps

cheers

Edited June 7, 2009 by Benzino33

[XxNinjaxX]

no its not pumping smoke at all, it just revs between 500-1000 rpm until its warmed up. other than that the car runs fine, although its boosted to 10psi with no boost controller..im not sure how thats been done but if someone could also shed some light on that it would also been helpful =D what can i clean the iac with? just some breakcleaner or do i need throttlebody cleaner? i was thinkin of giving it a upper cylinder purge to try to clean out any crap thats in the system.

[TRB-001]

yeah brake cleaner works well.... also clean out your throttle body while your there with the same stuff... NOTE, avoid spraying the TPS or the throttle butterfly shaft as iv seen some cleaners eat out the TPS... so best way is to spray a rag and wipe out the throttle body...

as for the boost... they probably have put the r32 rb20det turbo wastegate actuator onto the stock turbo... from factory the r32 is set at 10psi

Edited June 7, 2009 by TRB-001

[Benzino33]

although its boosted to 10psi with no boost controller..im not sure how thats been done

That is because your stock solenoid has been earthed, leaving it at a high boost setting permanently.

same is on my car. just get a boost controller if u wanna adjust.

[TRB-001]

even better

[XxNinjaxX]

ahh cool thanks guys, yeah im not too worried about the 10psi boost, its not going to hurt anything as its still quite low and its probally as far as im willing to have it boosting to anyway to avoid any problems being caused. i'll clean the iac and give it a throttle body clean to try and sort out the hunting and may even run a injector cleaner to see if that will clear anything up aswell, as i dont know the service history of the car. As for a running mildy rich, what sort of things may i be looking at that could/will cause the engine to do so (im aware that the extra boost with no extra management may cause the ecu to dump fuel to counter the extra air being forced in) but if anyone knows of any other known causes of rich running then dont hessitate to list them down. as ive said earlier the car doesnt blow smoke at all, its just got a strong exhaust smell.

[REDGTT]

When you start the car up and it is cold idleing it is in closed loop mode. All sensors are shut off and only sensor it uses is the oxygen sensor (o2). IF this is faulty then hunting will occur as the ECU gets no reading and dumps fuel constantly and that rev hunting is the fuel dump.

O2 sensor is also used when you cruise (light throttle) This will cause your car to surge or if not run quite rich. I suggest you change your o2 sensor first.