idle problems

[nappyroots827]

hey guys, i just finished my p&p cylinder head and efi swap and i started the car up and everything ran smooth but it idles really really high, like 3000 and it doesn't go down, even at operating temperature, and if i let it sit for a while, the idle starts bouncing up and down, like its gonna stall than picks back up, but when i put it in gear, this stops, any ideas on whats wrong, i need help and fast

[86LXItooFAST4me]

you reset the ECU right? and timing is fine and you sure you got all the vacumm lines right.

[smufguy]

these are the things you need to check

1) check and see if your PCV hose and valve are not leaking. you can try this by pulling the pcv hose out of the intake Manifold and put a blocker on it or close it with your thumb and let it idle, see if it helps

2) adjust your throttle stop screw. Its a flat head screw right on top of the TB

3) Fast Idle Valve: These are usually the idle screw ups. DO NOT OPEN AND ADJUST THESE. The rubber valve is usually rott to hell and even the manual says u should not adjust the factory setting. I tried it once and it made it worse. Grab a few from the junkyard and see if they work. If not try to rebuild it using the instructions from the shop manual since a new one from the dealer would wanna make you sell ur nuts.

4) Check the tension on the Throttle cable. If its tightened too much, idle will be high and u will see ur cat literally glow

5) Sticky TB. See if the Thorottle plate releases freely. If its like mine. Take a soft wire wheel on a dremel to it and take out the carbon deposits.

IF the problem still persists after the above trouble shootings, let us know.

PS: By the way, you should have posted this thread in the Technical section, not perf.

[superguillermo]

Also, make sure u bleed your cooling system of any air bubbles. Very common for idling problems.

[nappyroots827]

hey, so far ive bled the cooling system, and the vacuum lines are all correct, the only thing is two of them go to the stock airbox, but i have an intake so i don't have em hooked up yet, but ive plugged em and it didn't help any...Im pretty sure its not my fast idle valve either because unless its lodged open, my cars idle doesn't slow down even at operating temperature, so i guess ill check the pcv hose, and fool around with the throttle linkage all and that and see if i get anywhere

[nappyroots827]

welp, i solved the high idle at start up, but now for some reason it will idle normal, but when i hit the gas it revs up and doesn't really drop back down...Any ideas what may cause this??