rb20det idle problem

[blues14]

Ok, when i adjust my idle, I pull the brown plug, adjust it to where it should be, then i shut the car off, plug the brown connector back in and start it up. but the problem is that when i rev the motor, the car will either almost die, or nearly die before getting to the set idle. unless i leave the idle at 800 rpm, it has this problem. what could be causing that? is it ok let keep my idle at 800 rpm?

[Joe]

check your timing.

[goofynick6]

Are BOTH plugs on the TPS plugged in? The one that plugs directly onto the TPS is an idle switch, it has to make contact internally or the ecu doesn't know the car is trying to idle and it will stall.

Nick

[Carl H]

a tech at work told me how to set the idle on these ecu's.what needs to be done is the car warmed up and running at temp.unplug the oval plug (3wire) from the tps and let the engine do its thing.it should idle up to bout 1.2kish then drop down to 500ish.when it does this set desired idle on the AAC with the screw on the side, reconnec the tps and race the engine a bit.it should hold an idle now at where you want it to.

[goofynick6]

When setting the AAC, unplug the brown plug going to it though, otherwise it will try to correct for the new incoming air and keep the idle steady where it was at.

Nick

[blues14]

ok, so here are the steps i should take, let me know if i am missing something.1. get car to operating temp2. unplug oval connector near TPS3. unplug brown connector on AAC4. adjust idle screw5. plug connector near TPS in6. plug AAC back in7. race engine to see if desired rpm is maintained.

My timing is set at 15 degrees. i actually just checked it yesterday. The guy at the shop said i should check the timing marks on my cam gears as he thinks one of them might be advanced a tooth. but than again, he also thought it was a 260 hp motor, I told him its only a 2 lt. rated at about 210 and it has a tiny t25 turbo. I think he expected the car to be faster:)

[goofynick6]

Make sure the voltage on the tps is about .5 volts, and make sure the bottom two pins(wires) on the tps idle switch (plug directly on the tps) has continuity and when you move the throttle, it breaks continuity.

NIck

[blues14]

tried adjusting idle with the steps i listed above and still have the problem. If i let the car idle at 8-900 rpm, its all good. but when i drop it to 550-750, the idle drops down to like 300 rpm after i rev it and then bounces back to 700 and then it waivers between 600-700 rpm. is it ok to let it idle at 8-900 rpm? I know it will suck gas, but will it be a lot harder on the motor?

[Andrew85cm]

My car sounds like its at it a lot better when she idles at 800-850 any lower and it sounds rough as poo. I just go by ear and if she is idling well I keep it. 600-650 is what they say but like I said I have set her to 800 and it goes strong for the past year. I don't think it would be a big issue but you may wanna ask someone who knows more.

[Eikon]

Hey Blues... If your car idles well at 800.. that's fine. Let it idle at 800.

Sure you will use a little bit more gas than you did at 650.. but how often to you just let the car sit at idle? It's not like your a truck driver.

Have you tried cleaning your AAC? I did, and it wasn't a miracle fix, but it did help.

Just take off the AAC and get some carb cleaner and clean it out really good. That extra air brought in through the AAC is what helps the idle speed. If your AAC is all dirty/clogged with dust and grime, then the air will not flow through it well, and you won't get a nice idle.

Give it a shot and see what happens. Might help!

[blues14]

well, i guess i will go with the old saying "if it aint broke, dont try and fix it" cuz with my luck, i will clean the AAC and then my car wont start at all thanks guys.