S13 sr20det help - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

silvia_fiend · 01-20-2015, 02:49 AM

People of zilvia I need your help.
www.youtube.com/watch?v=8Ha9yMVuY_c
This is my car, jdm s13 with what I believe is a 180sx blacktop swapped in.
Mods:
440cc S15 injectors
T28bb
RB25 pink sticker afm
Full exhaust
PSM intercooler
EBC
Chipped ECU

Since I've owned the car there has been an issue with the idle and initially running very rich, the tune really helped things there but the idle would still surge/hunt and stall when clutching in rolling to a stop at lights etc, tuner wound the idle up which was a band aid fix but did the trick.

Fast forward to at least 6 drift days and a lot of driving later and the car runs great, but still has the idle issue and as you can see at the video still stalls out with a lot of momentum when clutching in and braking hard, usually when I spin it it'll stall too.

Things I have done, cleaned out IACV and put another in from a spare manifold, set TPS at .4v, cleaned MAF. The issue still persists.

The tuner mentioned the CTS reading was through the roof when we were tuning and I made a mental note to look into it, (he also disabled/tuned around the o2 sensor so that has been unplugged since the tune) recently bought a new CTS and installed which made no difference, however I did notice that the plug the CTS and temp sender for the dash connect to had the two trace wires (I think orange and blue) taped up, peeled the tape back to find them back to front i.e. orange connected to blue and vice versa, this is on the loom side of the plug.
At the same time I bought a consult cable and hooked up to my laptop, noticed with the engine not running the water temp was sitting at 50*C after switching the wires round the to the correct way the temp reading goes down to 30*C.

Now for the really strange part, the ECU was throwing no codes for the CTS even though those wires were back to front, does this make sense? After I switched them my cluster temp gauge stopped working so I switched them back and then started to get the CTS code.

I'm extremely confused, things I'm planning to check/try other parts are the AFM, vacuum/boost leak check, timing. Any other suggestions? What gets me is the car was running great, besides the idle, and now it's gone back to running really rich, wouldn't start a couple days back and I pulled the plugs to find them all black, I'm wondering if rewiring those wires has thrown the tune off after the tuner maybe compensated for it originally?

Any help or advice is MUCH appreciated!

pacotaco345 · 01-20-2015, 06:54 AM

How far is your MAF from your turbo inlet? Do you have a BOV or do you just surge? If you have one is it vented to atmosphere? Do you have a lightweight flywheel? Is there a wideband in the car?

My car has the same issues but I credit it to a lot of small issues I know I have with my setup:
My crankcase is vented to atmosphere instead of run to a catch can and back to the intake, my intake pipe is only about a foot long with one bend in it, I have cams, I have a lightweight flywheel and I have no idea if my o2 sensor actually works the way it should.

silvia_fiend · 01-20-2015, 10:18 PM

It's sitting right towards the front bumper not close to the turbo at all, no BOV, no wideband, pretty sure it has a lightweight flywheel, but I have a catch can and everything piped back in not vented to atmosphere.

Just remembered, giving the gas in neutral makes the revs dip and bog down, is this leaning more towards a vacuum leak?

pacotaco345 · 01-21-2015, 08:28 AM

Does it idle high when it does hold idle? That would point towards a vacuum leak. It could be the lightweight flywheel, when the rpms drop so fast the IACV can take a lil extra time to catch back up causing the car to bog or stall.

01-20-2015, 02:49 AM	#1
silvia_fiend Join Date: May 2008 Location: New Zealand Age: 34 Posts: 30 Trader Rating: (0) Feedback Score: 0 reviews	S13 sr20det help People of zilvia I need your help. www.youtube.com/watch?v=8Ha9yMVuY_c This is my car, jdm s13 with what I believe is a 180sx blacktop swapped in. Mods: 440cc S15 injectors T28bb RB25 pink sticker afm Full exhaust PSM intercooler EBC Chipped ECU Since I've owned the car there has been an issue with the idle and initially running very rich, the tune really helped things there but the idle would still surge/hunt and stall when clutching in rolling to a stop at lights etc, tuner wound the idle up which was a band aid fix but did the trick. Fast forward to at least 6 drift days and a lot of driving later and the car runs great, but still has the idle issue and as you can see at the video still stalls out with a lot of momentum when clutching in and braking hard, usually when I spin it it'll stall too. Things I have done, cleaned out IACV and put another in from a spare manifold, set TPS at .4v, cleaned MAF. The issue still persists. The tuner mentioned the CTS reading was through the roof when we were tuning and I made a mental note to look into it, (he also disabled/tuned around the o2 sensor so that has been unplugged since the tune) recently bought a new CTS and installed which made no difference, however I did notice that the plug the CTS and temp sender for the dash connect to had the two trace wires (I think orange and blue) taped up, peeled the tape back to find them back to front i.e. orange connected to blue and vice versa, this is on the loom side of the plug. At the same time I bought a consult cable and hooked up to my laptop, noticed with the engine not running the water temp was sitting at 50C after switching the wires round the to the correct way the temp reading goes down to 30C. Now for the really strange part, the ECU was throwing no codes for the CTS even though those wires were back to front, does this make sense? After I switched them my cluster temp gauge stopped working so I switched them back and then started to get the CTS code. I'm extremely confused, things I'm planning to check/try other parts are the AFM, vacuum/boost leak check, timing. Any other suggestions? What gets me is the car was running great, besides the idle, and now it's gone back to running really rich, wouldn't start a couple days back and I pulled the plugs to find them all black, I'm wondering if rewiring those wires has thrown the tune off after the tuner maybe compensated for it originally? Any help or advice is MUCH appreciated!

01-20-2015, 06:54 AM	#2
pacotaco345 Zilvia FREAK! Join Date: Jan 2010 Location: SoCal/Ft Worth TX Age: 30 Posts: 1,563 Trader Rating: (5) Feedback Score: 5 reviews	How far is your MAF from your turbo inlet? Do you have a BOV or do you just surge? If you have one is it vented to atmosphere? Do you have a lightweight flywheel? Is there a wideband in the car? My car has the same issues but I credit it to a lot of small issues I know I have with my setup: My crankcase is vented to atmosphere instead of run to a catch can and back to the intake, my intake pipe is only about a foot long with one bend in it, I have cams, I have a lightweight flywheel and I have no idea if my o2 sensor actually works the way it should. __________________

01-21-2015, 08:28 AM	#4
pacotaco345 Zilvia FREAK! Join Date: Jan 2010 Location: SoCal/Ft Worth TX Age: 30 Posts: 1,563 Trader Rating: (5) Feedback Score: 5 reviews	Does it idle high when it does hold idle? That would point towards a vacuum leak. It could be the lightweight flywheel, when the rpms drop so fast the IACV can take a lil extra time to catch back up causing the car to bog or stall. __________________

01-20-2015, 10:18 PM	#3
silvia_fiend Join Date: May 2008 Location: New Zealand Age: 34 Posts: 30 Trader Rating: (0) Feedback Score: 0 reviews	It's sitting right towards the front bumper not close to the turbo at all, no BOV, no wideband, pretty sure it has a lightweight flywheel, but I have a catch can and everything piped back in not vented to atmosphere. Just remembered, giving the gas in neutral makes the revs dip and bog down, is this leaning more towards a vacuum leak?