Idle Control

[dantesdoom]

I need some help with the idle on my manual NA. It cranks and runs good, new injectors, and code 55..so all is ok. But...my car will turn over a run, but when it warms up the car will shut off if the gas pedal is not slightly pressed. Also, if it does level out, it will only idle at around 600rpm and move up and down +/- 100rpm. It might be good to note that any rev will result in the car shutting of, and if you drive it and clutch, the rpms will fall past idle to 0. So, does this sound like and idle issue, or what. I was going to check the IACV tom. and i played with the throttle cables today. Any ideas would be good

[Zwicked]

Start by properly adjusting the idle, but you may have other issues if it stalls when you push on the accelerator.

- warm the engine to operating temp- shut the engine off and disconnect the AAC connector- start the engine, and set the idle to about 650 RPM using the screw on the side of the IACV unit- while it's running, plug the AAC back in. *The idle should increase and settle to about 750. If nothing happens, the AAC solenoid is dead (of the IACV unit is gummed up inside)

Report back once you've tried this

[dantesdoom]

Will do, might be next friday before i have time to get back around to this, but ill post on here and let you know what happens as soon as i do...thanks!

[Ghut300zx]

im having idle issues too

is this the screw you are talking about?

[Ghut300zx]

and where is the connector?

[Zwicked]

Yes, that's it. The connector is at the other end of where the screw is. There's an upper and a lower connector. The upper one is the one you want

[Ghut300zx]

man thats gonna be a b**** to get to

[dantesdoom]

man thats gonna be a b**** to get to

haha this is nothing to get to compared to the rest of the car...IMO its gonna be pretty simple compared to things such as the fuel injectors, fuel lines, or even some connectors...i hope i can get around to it today

[Zwicked]

No it's easy. Look from the top, it's right there.

[Ghut300zx]

ok i went out and did everything you said but when i plugged the aac back in it shot right back up to 1000rpm (where it was before)

i took some pics in the proccess so i can make a how-to thread for other people later on but my email wont recieve the pictures

[Ghut300zx]

http://zclub.nicoclub.com/zerothread/477131

here it is

[Ghut300zx]

so why does my idle jump back up?is the solenoid bad?

[dantesdoom]

Alright i did as was suggested...partly...here were my findings:

Car idles at 750 rpm until warm...idle becomes erratic when it warms up. Unplugging the sensor on the IACV did not yield any results, as i couldn't get the idle to balance out with/without the sensor unplugged, so i couldn't accurately set it to the rpm suggested (fluctuates as much as ~300rpm). Idle seems to be set to 750 rpm, but jumps when the car warms up...almost like the motor is compensating for something....other than that the car runs good...especially when cold. Ideas?

[Ghut300zx]

thats really wierd.does your idle change AT ALL when you unplugg that wire?and i was thinking either vacum leak or absolute manifold pressure or temp sensor?

crazy possesed car

[Zwicked]

2 ideas:

..but first, have you run ECU diagnostics as well as the o2 sensor tests?

1. Have you ever pulled any of the connectors with the spring clip to see if they are corroded? If not, pull the one off the Coolant Temp Sensor and have a look if there is any green corrosion. The CTS not working can cause weird behavior.

2. Possible vacuum leak.

[Ghut300zx]

ok i went out and did everything you said but when i plugged the aac back in it shot right back up to 1000rpm (where it was before)

anyone?

[vape-one]

I know you got a 55 but it could be your TPS or ECU..?? Just two guesses... Good luck..

[dantesdoom]

my work for tomorrow is planned like this:1. check for vacuum leaks2. Try cleaning the IACV with WD-40?...any ideas as to the legitimacy of this? http://s95014253.onlinehome.us/63104/157335.html 3. I had replaced the CTS with a Napa one, so I cleaned the corrosion off the old Nissan one and was thinking about swapping it back in if all else fails.4. Will check the O2 sensors5. Check/clean TPS connectors and IACV connectors as well... recheck the CTS connectors...can some corrosion cause this problem....or is it a pretty much all or nothing sensor....it either works or doesn't...or can its effectiveness be decreased with increasing corrosion?

I will give some feed back on this ASAP...although i might be a little late....its snowed like 4 inches in SC!....ahhaha im 21 years old and am excited to play in the snow

[dantesdoom]

Results inconclusive from testing...idle is high if it levels out.....i think the vacuum hose to the AIV isnt connected...possible problem if it isn't?