high idle rb20det

[bigfootap]

Finally got my car start! However, it is idling very high and after a few seconds proceeds to idle even higher.
Anyone know what this could be?

[TheRBguy]

Vacuum leak or something messed up with your idle air control valve.

[bigfootap]

alright. Anything else i should look for?

[Powered Bya Skyline]

iam having the exact same problem with mine but i unplugged the iac and the idle went up higher.. iam going to try the tps sensor? i dont know for sure if this will help.. check the vacuum line coming off the throttle body that runs parrell with the intake, theres 3 vacuum lines, one to the recirc value and the other 2 i think go to a boost controller? correct me if iam wrong.. but anyways the line that goes towards the throttle body on mine was leaking and causing a little leak but it only brought the idle down like 100 200 rpms.. iam idleing at like 1500 2000 rpms regardless of temp.. the car is not loping at all either.. the vacuum on the boost gauge is 12 13 pounds.. i know theres some type of leak but one that massive or the iac is really bad or clogged... curious could the high idle be caused by the maf giving the computer a high reading making the car think its getting more air than usual, causing the vechile to idle high?

[bigfootap]

Hmm the way you describe yours is the way mine is idling as well. I'm going to play with the cas and see what that does. Also i started it up today and let it run for a couple minutes and then i noticed smoke coming from th radiator so i shut it off and opened the cap and there was like rust colored liquid coming out of the radiator and i dont think my thermostat opened up. Guess i will try and flush the radiator and pour some water through it to see what happens.

[Powered Bya Skyline]

i am planning on rebuilding my rb20, well all the maintanice stuff.. timing belt, waterpump, so forth. i played with the cas a while ago but never while the car was running i just redid the timing on it. i do believe theres a major vacuum leak on mine.. if you look on the back of the intake plenum where the brake booster vacuum line goes on the the intake, theres a small bong that seems to be broken off on mine.. i will be trying to plug that and see what happens when i get the fuel pump... i dont know if thats suppose to be a controlled vacuum leak or what but its worth a shot.

[Carl H]

you need to check that the idle switch is engaging...99% of the time if the engine has no vacuum leaks it is due to an improperly set idle switch.

[bigfootap]

Was that directed towards both of us or one of us specifically carl? Do you know why my coolant would be rust colored and have some chunks in it?

[TheRBguy]

Mine is a bit rusty too but i wouldnt worry about it, it wont hurt anything.

[Powered Bya Skyline]

idle switch? would you be talking about the iac value?

[Carl H]

it was directed towards the original poster.
and no a stock setup the iacv should never have to be tweaked as they are normally set correctly from factory.

idle switch is part of the tps, and most people remove the harness from the engine which seems to be enough to toss the tps off which in turn will also muck with the idle switch.

[bigfootap]

So what can I do to correct the TPS? and where exactly is the idle switch? image?

Does anyone know what might cause my coolant to become a brown muddy substance and even do it to water when trying to flush? I've flushed it a few times now.

[Powered Bya Skyline]

the tps is the throttle position switch... its adjustable on the side of the throttle. ive never herd of the tps being the idle switch.. all in all it does all the same thing. i was also thinking that might cause the high idle.. but i wanted to make sure the vacuum leaks are all good.

[Gabes13]

There are two parts to the tps, the actual sensor it self that measures the throttle plate movement, and the idle switch. You'll see bc there are 2 connectors on the tps. Both connect to the harness. Check the fsm for voltage and resistance testing on both connectors. I know on Ka motors, if the tps is bad, the iacv unit is bypassed. idk it it's the same on rb.