extremely lean and stalling out - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Birdman12 · 09-23-2008, 09:21 AM

Hey guys, I've been doing a lot of reading and trying to narrow down what is happening but no luck...

here's the story: for a while (about 2 weeks or so) on start up the car has been hesitating quite a bit and idling lean but not stalling just rough idle around 800rpm and dipping down a little and then I would drive it out and then it would idle just fine. It also sounds like my external wastegate is staying open under idle and light throttle...I can hear it and I have no idea why, this was never happening before. Now, this past weekend I put a 3" downpipe on finally and put a testpipe on. I did not touch anything in the engine bay. And after I go to start it up to hear the exhaust I can clearly hear the wastegate open and it won't even hold idle, It just shoots up to 1200-1500rpm then drops down fast and dies if i don't give it gas.

-when driving, car boosts fine but stalls as soon as I clutch in or come to a stop without me giving it gas
-I have checked for vaccum and boost leaks as best as I can.
-checked the bov (not stuck open)
-took the wastegate off and inspected spring, bladder and valve seal. all fine
-I try to correct for the fuel with my safc-2 on +50% fuel and still lean...

My setup:
s14 ka24de
T3/T4 Air Research
550cc
aem fpr
z32 maf
jim wolf ecu
safc-2
38mm external wastegate
old school hks bov

I am going to try to reset the ECU and see if it is flashing any codes. I don't understand why it would just start doing this and running really lean.

any suggestions would be great! thanks in advance.

Phil

*fliprayzin240sx* · 09-23-2008, 01:23 PM

Double check your timing...

Birdman12 · 09-26-2008, 10:01 PM

well it turned out to be a vaccum leak and my safc-II decel air setting were all fucked up so i reset them again and got it idling perfect. still a little bit of hesitation on start up but give it a shot of gas and it smooths out.

im going to try to find every little vac and boost leak and get them all patched up or fixed somehow and clean out my iacv, and re-gap my plugs for now.

question: on start up there is quite a bit of smoke/gas comming out of the valve cover breather. I don't have a catch can or filter on it and it spits oil now and then....what should i do about this? and is this bad?

Phil

F3600 · 10-05-2008, 11:38 AM

A very lean reading on a wideband at idle = Super rich mixture. Glad you the problem.

09-23-2008, 09:21 AM	#1
Birdman12 Join Date: Dec 2006 Location: Ottawa, Ontario, Canada Age: 33 Posts: 10 Trader Rating: (0) Feedback Score: 0 reviews	extremely lean and stalling out Hey guys, I've been doing a lot of reading and trying to narrow down what is happening but no luck... here's the story: for a while (about 2 weeks or so) on start up the car has been hesitating quite a bit and idling lean but not stalling just rough idle around 800rpm and dipping down a little and then I would drive it out and then it would idle just fine. It also sounds like my external wastegate is staying open under idle and light throttle...I can hear it and I have no idea why, this was never happening before. Now, this past weekend I put a 3" downpipe on finally and put a testpipe on. I did not touch anything in the engine bay. And after I go to start it up to hear the exhaust I can clearly hear the wastegate open and it won't even hold idle, It just shoots up to 1200-1500rpm then drops down fast and dies if i don't give it gas. -when driving, car boosts fine but stalls as soon as I clutch in or come to a stop without me giving it gas -I have checked for vaccum and boost leaks as best as I can. -checked the bov (not stuck open) -took the wastegate off and inspected spring, bladder and valve seal. all fine -I try to correct for the fuel with my safc-2 on +50% fuel and still lean... My setup: s14 ka24de T3/T4 Air Research 550cc aem fpr z32 maf jim wolf ecu safc-2 38mm external wastegate old school hks bov I am going to try to reset the ECU and see if it is flashing any codes. I don't understand why it would just start doing this and running really lean. any suggestions would be great! thanks in advance. Phil

09-23-2008, 01:23 PM	#2
fliprayzin240sx Man w/ CTSV & a Car Seat Join Date: Aug 2002 Location: Tampa Posts: 17,998 Trader Rating: (19) Rides Gallery: fliprayzin240sx Feedback Score: 19 reviews	Double check your timing... __________________ If you think Zilvia has too many assholes... CLICK HERE!!!

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09-26-2008, 10:01 PM	#3
Birdman12 Join Date: Dec 2006 Location: Ottawa, Ontario, Canada Age: 33 Posts: 10 Trader Rating: (0) Feedback Score: 0 reviews	well it turned out to be a vaccum leak and my safc-II decel air setting were all fucked up so i reset them again and got it idling perfect. still a little bit of hesitation on start up but give it a shot of gas and it smooths out. im going to try to find every little vac and boost leak and get them all patched up or fixed somehow and clean out my iacv, and re-gap my plugs for now. question: on start up there is quite a bit of smoke/gas comming out of the valve cover breather. I don't have a catch can or filter on it and it spits oil now and then....what should i do about this? and is this bad? Phil

10-05-2008, 11:38 AM	#4
F3600 Zilvia Junkie Join Date: Apr 2002 Posts: 364 Trader Rating: (0) Feedback Score: 0 reviews	A very lean reading on a wideband at idle = Super rich mixture. Glad you the problem.