Sr20det unstable idle/stalls - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

BCHLR240SX · 07-17-2013, 06:51 PM

Ok, so I really didn't want to do this but I need to ask for some input, I have been trying to diagnose this sr for days and sadly, I've HAD NO luck in finding the problem.. My brain is fried and I'm hoping I'm overlooking/neglecting something.

Original issue was a no start. After a rainy day, I go to crank the car and it doesn't start. Keep trying and it's a no go, I'm late for work and I leave it. Go to start it the next day and voila, cranks up right away. Turn it off and try again a couple times and it seems to be ok, so I go in and eat some breakfast and come back out 10 minutes later. To my surprise car doesn't start.. wtf...

Tow it to my shop test and it seems the no start has sorted itself out. Car has started up since the weekend but now it's running like a bag of shit..
It's missing and cutting out in the higher rpms, and it stalls if the revs aren't kept up.

Here's what I tested so far:
Continuity between ground circuit and power circuit on injectors
Injector pulse
Injector impedence
Fuel pressure
Spark
Vacuum leaks
ECT resistance
Swapped CAS/ignitor chip/ECU
Checked grounds, fuses
I've cut open the engine harness to check for corroded wires

Bottom line I have fuel/spark/air

Also I've check for timing but I'm not sure if it's off cause it's running like shit, or it's running like shit because it's off. Can't get it to idle so I sort of neglected that as an issue for now.

Thoughts anyone?

Mikester · 07-18-2013, 06:43 AM

I know you verified your grounds, but this can be deceptive. Change out the negative battery cable; even if it isn't corroded.

IMHO, this sounds like water in your fuel, or just shit gas. Hopefully you never used a fuel system cleaner or octane booster because those things cook RB & SR plugs.

Another thing could be the coilpacks subharness... They get pretty brittle over time and sometimes cause weird ignition issues.

GL!

BCHLR240SX · 07-18-2013, 07:20 AM

I'll give those a shot today

cotbu · 07-18-2013, 02:55 PM

Check the ecu for codes. If you have no led or the check engine light isn't wired up? look for alternatives. They're out there!

07-17-2013, 06:51 PM	#1
BCHLR240SX Leaky Injector Join Date: Apr 2009 Location: T.O. Posts: 62 Trader Rating: (3) Feedback Score: 3 reviews	Sr20det unstable idle/stalls Ok, so I really didn't want to do this but I need to ask for some input, I have been trying to diagnose this sr for days and sadly, I've HAD NO luck in finding the problem.. My brain is fried and I'm hoping I'm overlooking/neglecting something. Original issue was a no start. After a rainy day, I go to crank the car and it doesn't start. Keep trying and it's a no go, I'm late for work and I leave it. Go to start it the next day and voila, cranks up right away. Turn it off and try again a couple times and it seems to be ok, so I go in and eat some breakfast and come back out 10 minutes later. To my surprise car doesn't start.. wtf... Tow it to my shop test and it seems the no start has sorted itself out. Car has started up since the weekend but now it's running like a bag of shit.. It's missing and cutting out in the higher rpms, and it stalls if the revs aren't kept up. Here's what I tested so far: Continuity between ground circuit and power circuit on injectors Injector pulse Injector impedence Fuel pressure Spark Vacuum leaks ECT resistance Swapped CAS/ignitor chip/ECU Checked grounds, fuses I've cut open the engine harness to check for corroded wires Bottom line I have fuel/spark/air Also I've check for timing but I'm not sure if it's off cause it's running like shit, or it's running like shit because it's off. Can't get it to idle so I sort of neglected that as an issue for now. Thoughts anyone?

07-18-2013, 06:43 AM	#2
Mikester Nissanaholic! Join Date: Jun 2007 Location: Kathleen, GA Age: 52 Posts: 1,956 Trader Rating: (0) Feedback Score: 0 reviews	I know you verified your grounds, but this can be deceptive. Change out the negative battery cable; even if it isn't corroded. IMHO, this sounds like water in your fuel, or just shit gas. Hopefully you never used a fuel system cleaner or octane booster because those things cook RB & SR plugs. Another thing could be the coilpacks subharness... They get pretty brittle over time and sometimes cause weird ignition issues. GL! __________________

07-18-2013, 02:55 PM	#4
cotbu Post Whore! Join Date: Sep 2005 Location: SWFL Age: 49 Posts: 3,318 Trader Rating: (3) Feedback Score: 3 reviews	Check the ecu for codes. If you have no led or the check engine light isn't wired up? look for alternatives. They're out there! __________________ LoverTechnologies "Half Broken Things!"

07-18-2013, 07:20 AM	#3
BCHLR240SX Leaky Injector Join Date: Apr 2009 Location: T.O. Posts: 62 Trader Rating: (3) Feedback Score: 3 reviews	I'll give those a shot today