Bad lag - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

NISMO NES · 03-05-2008, 07:47 PM

Alright heres the situation my car was 25degrees advanced i set it bck to 15degrees... but there something wrong with my IACV either bad ground or its broken all I know is that its stuck and i have to set it manually so it works... now wen im shifting it pulls around 3200 like if it wants to go then all of a sudden im pressing on the gas but the car doesnt pick up speed and that happens in every gear before i did the timing it didnt have that problem

... I jst did this like 20min ago so wat could it be? any help guys and gals thanks.

Harris · 03-05-2008, 07:53 PM

That's a long sentence, but let me try to answer.

Evidently, you had timing set to 25* BTDC, and now you set it right to 15* BTDC. With a 10* timing drop, power will most definitely be lower, but rightfully at a safe level compared to when you had it way beyond factory specs.

I think the other issue you have at hand is that of high idle. If that's the case, have you tried the screw on the IACV (Idle Air Control Valve) to see if that helps? If the car won't do anything when trying to set the idle with the IACV, then you simply need to buy a new unit. I believe Phase2MotorTrend houses that part for about $150. That should solve your problem.

Good luck.

NISMO NES · 03-05-2008, 08:02 PM

Thats kind of weird cuz the motor still has all it stock pipings i heard if i upgrade to front mount wit a blow of valve that realeses the air out thats wen ill have problems with my IACV and have to replace it or maybe im not letting enough air into my motor or to much in it...

Harris · 03-05-2008, 08:07 PM

I am having a hard time answering you right because you're not articulating your problems correctly. So I can't really say what you're dealing with exactly. A bad IACV can go bad at any time, with or without an FMIC with an open-air or recirculated BOV. I ran my car with an FMIC and open-air BOV with no idle issues. You just have to set the BOV right so that it doesn't cause the car to stall, that's it.

I now run a huge intake manifold with a Q45 TB which has led to idle issues, but I've found out why. It came to a bad IACV and the fact that I might need to run two IACVs in conjunction with each other so that air/vacuum can be properly monitored (this conclusion comes from the experiences of another person using the same intake manifold as myself, but just on a FWD SR20DET).

NISMO NES · 03-05-2008, 08:16 PM

im gonna try 2 paly with my car a liittle and fuck around with the IACV just 2 see if theres any change if not im just gonna set it to 20 degrees and see wat happens be bck in a bit...

Harris · 03-05-2008, 08:26 PM

I wouldn't mess with the ignition timing. IIRC, factory specs require you to keep ignition timing to 13* +/- 2* BTDC. 25* BTDC is a BAD idea. I'm sure others would say the same here, given the fact that you have a turbocharged SR20 and you're presumably running pump gas. Either way, good luck.

03-05-2008, 07:47 PM	#1
NISMO NES BANNED Join Date: Jan 2008 Location: Alhambra Posts: 22 Trader Rating: (0) Feedback Score: 0 reviews	Bad lag Alright heres the situation my car was 25degrees advanced i set it bck to 15degrees... but there something wrong with my IACV either bad ground or its broken all I know is that its stuck and i have to set it manually so it works... now wen im shifting it pulls around 3200 like if it wants to go then all of a sudden im pressing on the gas but the car doesnt pick up speed and that happens in every gear before i did the timing it didnt have that problem ... I jst did this like 20min ago so wat could it be? any help guys and gals thanks.

03-05-2008, 07:53 PM	#2
Harris Leaky Injector Join Date: Jun 2005 Location: Fort Riley, KS Age: 44 Posts: 77 Trader Rating: (2) Feedback Score: 2 reviews	That's a long sentence, but let me try to answer. Evidently, you had timing set to 25* BTDC, and now you set it right to 15* BTDC. With a 10* timing drop, power will most definitely be lower, but rightfully at a safe level compared to when you had it way beyond factory specs. I think the other issue you have at hand is that of high idle. If that's the case, have you tried the screw on the IACV (Idle Air Control Valve) to see if that helps? If the car won't do anything when trying to set the idle with the IACV, then you simply need to buy a new unit. I believe Phase2MotorTrend houses that part for about $150. That should solve your problem. Good luck.

03-05-2008, 08:02 PM	#3
NISMO NES BANNED Join Date: Jan 2008 Location: Alhambra Posts: 22 Trader Rating: (0) Feedback Score: 0 reviews	Thats kind of weird cuz the motor still has all it stock pipings i heard if i upgrade to front mount wit a blow of valve that realeses the air out thats wen ill have problems with my IACV and have to replace it or maybe im not letting enough air into my motor or to much in it...

03-05-2008, 08:07 PM	#4
Harris Leaky Injector Join Date: Jun 2005 Location: Fort Riley, KS Age: 44 Posts: 77 Trader Rating: (2) Feedback Score: 2 reviews	I am having a hard time answering you right because you're not articulating your problems correctly. So I can't really say what you're dealing with exactly. A bad IACV can go bad at any time, with or without an FMIC with an open-air or recirculated BOV. I ran my car with an FMIC and open-air BOV with no idle issues. You just have to set the BOV right so that it doesn't cause the car to stall, that's it. I now run a huge intake manifold with a Q45 TB which has led to idle issues, but I've found out why. It came to a bad IACV and the fact that I might need to run two IACVs in conjunction with each other so that air/vacuum can be properly monitored (this conclusion comes from the experiences of another person using the same intake manifold as myself, but just on a FWD SR20DET).

03-05-2008, 08:16 PM	#5
NISMO NES BANNED Join Date: Jan 2008 Location: Alhambra Posts: 22 Trader Rating: (0) Feedback Score: 0 reviews	im gonna try 2 paly with my car a liittle and fuck around with the IACV just 2 see if theres any change if not im just gonna set it to 20 degrees and see wat happens be bck in a bit...

03-05-2008, 08:26 PM	#6
Harris Leaky Injector Join Date: Jun 2005 Location: Fort Riley, KS Age: 44 Posts: 77 Trader Rating: (2) Feedback Score: 2 reviews	I wouldn't mess with the ignition timing. IIRC, factory specs require you to keep ignition timing to 13* +/- 2* BTDC. 25* BTDC is a BAD idea. I'm sure others would say the same here, given the fact that you have a turbocharged SR20 and you're presumably running pump gas. Either way, good luck.