KA24E High Idle after warm up. SOHC Genius' look here

[KiLLeR2001]

If you want to check continuity you would need to check from ECU harness plug to the IACV plug.

You most likely have one of the following problems:

- A break in a wire somewhere / damaged harness / ECU plug not fully seated etc
- IACV is completely non-functional
- ECU has an issue in the IACV circuit

[firefighter573]

I have put 2 different IACV (Completely clean) in and still have the issue. - Ruled out

I will remove the ECU, crack it open and look inside to see any visual defects.

Tomorrow I will inspect the wires and grounds to ensure everything is proper.

[KiLLeR2001]

You can find all the ground wire locations in the FSM.

http://www.nicoclub.com/FSM/240sx/91-94/EL.pdf

Page 90 on down has the harness layout with various grounds.

[firefighter573]

Would the SOHC FSM be any different than the DOHC FSM?

Thanks for the added research!

Heres the SOHC FSM for other people digging for answers:

http://www.nicoclub.com/FSM/240sx/1989/1989.pdf

[firefighter573]

Cracked open the ECU, FRESH AS FFUUUUUUUU.

Everything appears to be in order, no faults, burns, anything of the sort. (shook the ECU first before opening it to listen for broken internals)

Onto checking the harness and grounds

[lbogkush]

i also had this problem when i first got my car SOHC89
changing idle isn't that hard idk if u tried this yet but it worked for me
follow this link it also apply for SOHC http://zilvia.net/f/s-chassis/395413...-pictures.html
EXAMPLE:
make sure car is warmed up drive whatever just make sure its warm up
shut car off open hood take tps plug off
(first picture of tps in the link is right but pull out the gray plug next to the screw with the red black yellow wire easier)
go back into car then start and let it idle for 10sec to where ever it idles to then
adjust the idle screw (second pic is correct)
turn left to rise idle right to lower idle
i just lower idle all the way then worked it up to 700RPM stock idle for manual
once it at the idle u want shut car off first take the key out of ignition THEN go plug the tps back in MAKE SURE or it will throw CL
after u shut car off then plug tps back in
start it back up and see if it idle where u wanted

if you did this right and idle doesnt go down it might be because you move your dizzy moving dizzy bring idle down i heard but i never tried it i heard it mess up timing try putting dizzy back to the right angle if that doesnt work sry
idk something u can do maybe it might help

[siksyndicate]

Originally Posted by lbogkush

i also had this problem when i first got my car SOHC89
changing idle isn't that hard idk if u tried this yet but it worked for me
follow this link it also apply for SOHC http://zilvia.net/f/s-chassis/395413...-pictures.html
EXAMPLE:
make sure car is warmed up drive whatever just make sure its warm up
shut car off open hood take tps plug off
(first picture of tps in the link is right but pull out the gray plug next to the screw with the red black yellow wire easier)
go back into car then start and let it idle for 10sec to where ever it idles to then
adjust the idle screw (second pic is correct)
turn left to rise idle right to lower idle
i just lower idle all the way then worked it up to 700RPM stock idle for manual
once it at the idle u want shut car off first take the key out of ignition THEN go plug the tps back in MAKE SURE or it will throw CL
after u shut car off then plug tps back in
start it back up and see if it idle where u wanted

if you did this right and idle doesnt go down it might be because you move your dizzy moving dizzy bring idle down i heard but i never tried it i heard it mess up timing try putting dizzy back to the right angle if that doesnt work sry
idk something u can do maybe it might help

I think you're the only one who asked about his timing. Is it loose? or way advanced?

[firefighter573]

Why would timing be attached to any issue that's going on here?

The Ignition timing is dead center,

The car idles high only under 15 mph, it's something electronically controlled that is causing the issue.

However, thanks to a friend I got my hands on a nice Snap-On Solus scanner and the issues became present!
4 codes found

[firefighter573]

HIGH IDLE IS GONE!
ISSUE?? One of something which was replaced below.
Heres the story:
As i was driving the car, somehow my LF tire picked up a rock, and let go of it right up into the engine bay landing directly into the ignition coil, destroying it, and all the spark plugs fouled instantly...sounds fucking stupid right? Pics or BS? look below.



So, I went and purchased a new ignition coil, plugs, and wires. Installed everything, started the car, and took it for a spin, kept driving it and then realized..."Its not idling high!?". THE HIGH IDLE IS GONE, Idling at 1000 rpm now. So where did the issue come from?
My assumption would be the aftermarket Accell Race wires, would the rather large wires with a stock ignition coil cause this?

[Mishkin_707]

That's a 1 in a 1,000,000 shot.....lol glad you got it figured out

[KiLLeR2001]

1000 is still a high idle.

[Mishkin_707]

Maybe now he just has to adjust his idle