SR Idles too High 1400RPM

[BobbyBoy]

ever since the motor was put back in, I have been having idle gremlins, after it warms up at will sit at about 1400rpm, randomly when I am driving around for awhile and come to a light the rev will sometimes sit anywhere from 1000-1400.

When it's hooked up to the Nissan Consult the timing will jump from 15-30 so I need to solve this idle problem before I start pushing the car hard and get it dyno tuned for more boost.

I have tried adjusting the idle air control screw all the way down and nothing seems to happen. I have another Idle air control valve to try to install but want to see if there are any other tips before I start doing all the bitchwork.

[Eternal_240Sx]

maybe the iacv is dirty. my idle used to idle between 1000-1800. i took my whole intake manifold off and cleaned the whole thing. Took the entire screw out and sprayed the hole out of it with a shit load of carb cleaner. after that my idle was fine.

[sdtouge]

maybe your timing chain is off, my timing belt (yes its a belt) was 2 teeth off on the exhaust side and my car couldnt run, all the compression was leaking out. if yours was 1 tooth or so off the opposite way i think this could be the probelm.

im not shure but its something tocheck out.

[SRBURG13]

Does it ever go down to a normal idle? After install, there is the possibility that the throttle cable is just too tight and the butterfly on the tb is just being held open too far.... OR the butterfly on the tb is sticking open, cause that's happened to me.

[BobbyBoy]

The timing chain was never removed, so that wouldnt have changed from before when the idle was fine. The timing with a gun read 15, but with the consult tool it will erratically change to 30 sometimes.

I have tried messing with the throttle cable, even have disconnected it completely so the TB will stay shut, and it still idles high.

Most likely the Idle air control valve is dirty, it just sucks I gotta take all that shit off to fix it, with no tools or garage to work in.

[S14DB]

I would buy some carb cleaner and hose down your TB and butterfly and clean that up. Then spray it down the IACV feed tube.

[didderson]

Sorry to dig up an old thread but OP did you ever remedy this problem? what was the cause. I'm sitting at about a 1300 idle too. probably cause my TB was stuck closed when i got the motorset from water sitting in it. I cleaned the fk out of it though, should be ok. I'll loosen the throttle cable a little more tomorrow.

[SoguRacing]

ok, before you go taking your intake manifold off make sure your throttle body is set correctly. there should be a little screw that adjusts the opening of the throttle body for minimum idle air ( not the iacv ). make sure it's closed all the way and turn the screw "one full turn" to set back to stock value for min. idle air flow. then try adjusting the iacv accordingly. As for the timing chain theory..yes "timing chain" not belt, they do stretch over time as rubber belts do even though they're metal. it will fatigue due to heat and tension. a centimeter or two difference in the overall legnth will throw off you timing a few degrees though i doubt thats the problem. I would also recommend checking for vacuum leaks for they are a pain in the @ss to locate. good luck

[didderson]

^ Thanks man, I will try that, if i recall it's like 1/8 an inch sticking out. So too far in other words. I'll try it today but I think this will probably help.:hsdance:

[sr20boostn20]

check for vaccum leaks, everywhere.

[jakethesnake]

hey, im having the same problem, i kinda fixed it by adjusting my BOV a little tighter, also adjusting the idle on my ECU helped a little bit. Someone told me to check if i have enough grounds, im not sure if that will help but just an idea i guess...good luck

[didderson]

ok, before you go taking your intake manifold off make sure your throttle body is set correctly.

Thanks Soguracing, that did the trick! I was pretty sure I didn't have vacuum leaks because I just finished my swap and the lines are pretty cleanly routed. The TB block screw fixed it perfectly! It's funny what half a millimeter will do to your idle :rawk: +1 others should try it.

[2fast4y0u]

i will be trying this but to bump my idle up a tad...its reall low with cams and altima fans i need that little extra idle.

cant wait to try tomorrow

[johngriff]

Idle setup given everything is clean.

Warm up the car, piping hot. Bleed the air.
Unplug the tps, set the timing. 15 degrees
Set the tps voltage, closed .4-.5, open 4+.
Set the tb screw so it does not let the tb stick, but also does not let air in.
Set the AACV until the idle is desired, blip the throttle each time you make a SMALL ADJUSTMENT AT A TIME, to let the ecu re-compensate for the new amount of air.

Do this every time for godly luck.