zoldak

Don't really post on here but really need help have a s13 sr20det in my 71 datsun 510 have it running but for some reason will not return to idle after i rev on the engine. need a sr20 expert to help me. I'm no tard im a Nissan tech for a living just cant figure this out, and reaching out for help if anyone in the Fredericksburg area is extremely experienced with sr's and wiring and would like to help out a fellow nissan guy let me know.
Thanks a lot -Zoldak

jdm monkey

what have you done to fix it; nothing? first thing i would do is swap out/clean the IAC valve. Stock ecu? It may have a lean spot somewhere

TRQLESS

+1

Also check your vacuum/boost leaks.

zoldak

i have cleaned and adjusted iacv as well as set the tps properly and the timing is dead on. cannot find any vacuum leaks. also swapped my ecu out with a friends ( with his it will not even start his a is a 62 ecu for a manual redtop sr and mine is a 63 for a auto trans sr which does not make sense b/e everything that i have read says that a 62 and 63 should swap out with no problem) my harness has been cut down and simplified to be installed into my car not sure if that is causing me problems or if i have a bad iacv but cannot find a good test procedure for testing the iacv

jdm monkey

find/borrow (with an option of not returning) a good working IAC.
install that.
see what happens.

when you said "cleaned" did you make sure that the valve actually works without binding or did you just spray some cleaner janks into it?

did you try your ECU into his?

FLiPrayZin240sx

Have you checked to see if the throttle body is sticking? It could be sticking a bit and not closing all the way, letting extra air in so its bumping the idle. There's also a screw on the TB that cracks the TB plate open, that could be needing adjustment too.

CarShowz

Maybe the nut that keeps the idle position screw managed to vibrate out if it was loose. My idle position screw nut fell out n the vibration from driving forced the screw upward raising the idle. I didnt notice anything while driving but when I came to stop my car was IDLING at 2200rpm !!! The idle screw was about two teeth from falling out

CarShowz

Also your throttle cable could be too tight holding the throttle slightly open

driftthis

Stock sr20det?