Boost Issues, need help - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

kernel · 10-01-2006, 09:16 AM

When my engine come to boost, it goes VERY LEAN and make backfire like a automatic machine gun...

it happened on the highway when i wanted to snap it to pass someone. i heard a loud pop coming from the front then the car feel like all the power were gone when i come to boost.

i have checked all the coupler, everything is fine. I didnt changed the z32 fuel filter but i have checked it, it look fine. Same thing with the fuel filter in the fuel tank on the pump. The pump has good 12v, it wired on a relay directly to trunk mounted battery. its a walbro 255lph.

for my fuel mangement, i have an safc2 with 740cc & z32 maf. As for the maf, its not defect. I do have a greddy fmic and all the piping, coupler are fine.

i do have too a nismo fpr and the "vacuum" part can spin freely, i dont know if it could be defect and do not hold the pressure good?

The engine running perfectly without running boost...i have EBC with all setting to hold boost at 0 psi and i can run with it, np.

well, id like to know if someone has already got this problem and know where to look to get it fixed.

sry for my bad english and you guys can ask me any question so we can find out my problem, im looking on the board often, thanks.

punxva · 10-01-2006, 12:59 PM

it sounds like a tuning problem, since your using such big injectors, you should really be using a better form of fuel management

*NemeGuero* · 10-01-2006, 01:19 PM

Word.. SAFCs are only good to +-50% of stock injector sizes..

SR = 1.5 X 370 = 555cc
KA = 1.5 X 270 = 405cc

kernel · 10-01-2006, 01:52 PM

im running these injectors with safc2 and maf z32 since the beginning of summer and i have never got that problem before

my tune was ok and had no problem at all running 15 psi..i have AEM wideband in my car.

steve shadows · 10-06-2006, 06:49 PM

Quote:

Originally Posted by munkfu

i do have too a nismo fpr and the "vacuum" part can spin freely, i dont know if it could be defect and do not hold the pressure good?

Please specify.

kernel · 10-07-2006, 06:35 PM

well, i have solved my issue, it was a bad coilpack that wasnt firing enough good under pressure.

about my fpr, the part that has the vacuum port spin freely, there already thread about that on the forums i think, i know someone else had the same issue with it.

johngriff · 10-10-2006, 04:59 PM

If the FPR has an obvious vacum leak, it should be replaced immediately.

Pictures?

John

10-01-2006, 09:16 AM	#1
kernel Zilvia Addict Join Date: Jan 2005 Location: Canada Age: 40 Posts: 934 Trader Rating: (28) Feedback Score: 28 reviews	Boost Issues, need help When my engine come to boost, it goes VERY LEAN and make backfire like a automatic machine gun... it happened on the highway when i wanted to snap it to pass someone. i heard a loud pop coming from the front then the car feel like all the power were gone when i come to boost. i have checked all the coupler, everything is fine. I didnt changed the z32 fuel filter but i have checked it, it look fine. Same thing with the fuel filter in the fuel tank on the pump. The pump has good 12v, it wired on a relay directly to trunk mounted battery. its a walbro 255lph. for my fuel mangement, i have an safc2 with 740cc & z32 maf. As for the maf, its not defect. I do have a greddy fmic and all the piping, coupler are fine. i do have too a nismo fpr and the "vacuum" part can spin freely, i dont know if it could be defect and do not hold the pressure good? The engine running perfectly without running boost...i have EBC with all setting to hold boost at 0 psi and i can run with it, np. well, id like to know if someone has already got this problem and know where to look to get it fixed. sry for my bad english and you guys can ask me any question so we can find out my problem, im looking on the board often, thanks.

10-01-2006, 01:19 PM	#3
NemeGuero No more nissan. Join Date: Jan 2003 Location: RAIN, Washington. Age: 40 Posts: 8,132 Trader Rating: (10) Rides Gallery: NemeGuero Feedback Score: 10 reviews	Word.. SAFCs are only good to +-50% of stock injector sizes.. SR = 1.5 X 370 = 555cc KA = 1.5 X 270 = 405cc __________________

10-10-2006, 04:59 PM	#7
johngriff Post Whore! Join Date: Jun 2004 Location: Long Beach, CA Posts: 4,103 Trader Rating: (4) Rides Gallery: johngriff Feedback Score: 4 reviews	If the FPR has an obvious vacum leak, it should be replaced immediately. Pictures? John __________________ [email protected]

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10-01-2006, 01:52 PM	#4
kernel Zilvia Addict Join Date: Jan 2005 Location: Canada Age: 40 Posts: 934 Trader Rating: (28) Feedback Score: 28 reviews	im running these injectors with safc2 and maf z32 since the beginning of summer and i have never got that problem before my tune was ok and had no problem at all running 15 psi..i have AEM wideband in my car.

10-07-2006, 06:35 PM	#6
kernel Zilvia Addict Join Date: Jan 2005 Location: Canada Age: 40 Posts: 934 Trader Rating: (28) Feedback Score: 28 reviews	well, i have solved my issue, it was a bad coilpack that wasnt firing enough good under pressure. about my fpr, the part that has the vacuum port spin freely, there already thread about that on the forums i think, i know someone else had the same issue with it.