Bad Idle, even after CTS and TPS - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

zombiewolf513 · 01-28-2013, 08:32 PM

Question...

I'm having idle issues with my spec-r sr20. Idle will sometimes surge between 1000 & 2000 RPM, sometimes it'll just stay at 1500 RPM. While it's doing that, it won't go lean to engine brake and will lightly buck under partial throttle boost. IT'S INTERMITTENT. It will only happen whenever it wants to start happening despite engine temp/outside temp/abuse/babying.
At Idle and cruise the AFRs read ~14.5-14.7, under boost it runs a little lean (I'm running JWT S3 cams and no tune), when I drop to neutral for a light the AFRs start at 18.5 and very slowly work their way down in increments of ~1 back to the usual.

What I've tried to do to fix it so far:

-Changed to new CTS and reset ECU
-Changed to new TPS and properly adjusted it
-Unplugging the O2 doesn't help, the idle really went nuts (The O2 is brand new)
-Unplugging the TPS makes the car slowly drop in RPMs and die

Any ideas on what to try next before I start combing through my ECU connector with a multimeter?

Thanks in advance.

ultimateirving · 01-31-2013, 09:45 AM

two things, have u check the IACV that normally solves most idle issue.
SEcondly why are you runnin JWT S3 cams without a tune?

zombiewolf513 · 01-31-2013, 10:25 AM

iacv getting cleaned and dif gasket today.

I've read nowhere that says you must get a tune for them. In fact, I've heard/read that it really isn't necessary at all. I'm waiting for my GT2871R to arrive so I can put it on before I get my PS1000 tuned. No sense in getting 2 tunes in 1 month.

01-28-2013, 08:32 PM	#1
zombiewolf513 BANNED Join Date: Mar 2011 Location: AZ Age: 36 Posts: 1,682 Trader Rating: (6) Rides Gallery: zombiewolf513 Feedback Score: 6 reviews	Bad Idle, even after CTS and TPS Question... I'm having idle issues with my spec-r sr20. Idle will sometimes surge between 1000 & 2000 RPM, sometimes it'll just stay at 1500 RPM. While it's doing that, it won't go lean to engine brake and will lightly buck under partial throttle boost. IT'S INTERMITTENT. It will only happen whenever it wants to start happening despite engine temp/outside temp/abuse/babying. At Idle and cruise the AFRs read ~14.5-14.7, under boost it runs a little lean (I'm running JWT S3 cams and no tune), when I drop to neutral for a light the AFRs start at 18.5 and very slowly work their way down in increments of ~1 back to the usual. What I've tried to do to fix it so far: -Changed to new CTS and reset ECU -Changed to new TPS and properly adjusted it -Unplugging the O2 doesn't help, the idle really went nuts (The O2 is brand new) -Unplugging the TPS makes the car slowly drop in RPMs and die Any ideas on what to try next before I start combing through my ECU connector with a multimeter? Thanks in advance.

01-31-2013, 09:45 AM	#2
ultimateirving Zilvia FREAK! Join Date: Nov 2010 Location: arizona Age: 36 Posts: 1,521 Trader Rating: (1) Feedback Score: 1 reviews	two things, have u check the IACV that normally solves most idle issue. SEcondly why are you runnin JWT S3 cams without a tune? __________________ Z32 with lq4 swap Desert Street Scene \|\| Dssevents.com Last edited by ultimateirving; 01-31-2013 at 10:51 AM..

01-31-2013, 10:25 AM	#3
zombiewolf513 BANNED Join Date: Mar 2011 Location: AZ Age: 36 Posts: 1,682 Trader Rating: (6) Rides Gallery: zombiewolf513 Feedback Score: 6 reviews	iacv getting cleaned and dif gasket today. I've read nowhere that says you must get a tune for them. In fact, I've heard/read that it really isn't necessary at all. I'm waiting for my GT2871R to arrive so I can put it on before I get my PS1000 tuned. No sense in getting 2 tunes in 1 month. Last edited by zombiewolf513; 01-31-2013 at 12:06 PM..