SR bucking problem but no codes! - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

s13hatchback · 08-26-2008, 07:16 AM

I just swapped my redtop into another chassis and now the car starts bucking bad when i ease into the throttle, but it doesnt happen at wife open throttle.Mods are...

redtop
z32 maf(new)
greddy fmic
fujita intake (PoS)
Walbro pump

I put the boost back down to stock until i figure this out. The MAF is new as are the plugs and O2 sensor. The ECU is showing 55 no problems. I checked for boost leaks and intakes leaks and nothing. Anyone have similar issues or have had in the past i would greatly appreciate the help. Also the plugs are fine(beige color) and there was no fuel smell when i took them out.

Firestorm · 08-26-2008, 07:25 AM

is your ECU mapped for the Z32 MAFS?

s13hatchback · 08-26-2008, 08:29 AM

its a stock #62 ecu

clark · 08-26-2008, 08:39 AM

the #62 ecu is designed for a redtop SR MAF, not a z32 MAF. if your are using a Z32 MAF in an ecu that it was not dseigned for, you need some type of air/fuel controller like the ap;exi AFC, or a reflash of your ECU..

or get yourself the right MAF, or a SOHC KA24E maf.

s13hatchback · 08-26-2008, 08:48 AM

my bad thought i put that in there... i have an safc2

clark · 08-26-2008, 08:56 AM

so did you configure the safc2 to compensate for the z32 maf?

the settings are all over this forum.

HS13KLS · 08-26-2008, 09:21 AM

i thought it was 2 in 10 out hot wire..
i may be wrong..but thats what i thought.
check that out and see what happens

0wn3r · 08-26-2008, 09:46 AM

you recirculated or no?

s13hatchback · 08-26-2008, 10:17 AM

no not recirc. it an hks ssqv

*burnsauto* · 08-26-2008, 10:23 AM

double check that maf/wiring..granted it may be new, but defects to happen. double check all the wiring you did..make sure nothing is loose, it really sounds like the maf is cutting out/not getting a signal.

Black240Ct · 08-26-2008, 10:35 AM

check the voltages, im not sure if they are displayed on your safc, but get in there with a volt meter

s13hatchback · 08-26-2008, 12:38 PM

I believe it is displayed when you go to sensor check on the safc, though i dont know which one it is. If anyone does plz let me know...

if it is sensor 1. it is at 1.1V at idle

2 is at .25 at idle

s13hatchback · 08-26-2008, 01:50 PM

like i said the car idles fine but when i give it slight throttle it starts cutting out and bucking. then when i get to about 3500 rpms it runs fin again under a decent amount of throttle

s13hatchback · 08-26-2008, 03:36 PM

I just spent a few hours checking everything and the maf reads 1.25V when at idle and the boost gauge sits at zero even when the car is at idle. when i give it gas it starts to read vacuum until i hit boost and it reads the boost just fine.

Anyone have any other ideas?

0wn3r · 08-27-2008, 08:54 AM

Quote:

Originally Posted by s13hatchback

when i give it gas it starts to read vacuum until i hit boost and it reads the boost just fine.

Anyone have any other ideas?

wth? vacuum leak maybe? Mine sits at 19-21inHG at idle

BiG MiKE86 · 08-27-2008, 09:47 AM

sounds like u has a major vac. leak - ^^^ 0wn3r's numbers are what u should be reading - Goodluck

DDSR240 · 08-27-2008, 10:44 AM

damn I'm sorry bro I had that same problem and it turned out to be the fuel pump sock I know it sounds strange but try it. g/l

GSXRJJordan · 08-27-2008, 11:06 AM

Haha how can no one mention GROUNDS. Check your grounds, from the MAF to the body, from the ignition harness (coilpacks) to the head, to the body, and from the ECU to the body. That's much more likely to be the problem than SAFC settings, because your car idles correctly.

08-26-2008, 07:16 AM	#1
s13hatchback Join Date: Sep 2006 Location: Ramstein AB, Germany Age: 35 Posts: 22 Trader Rating: (0) Feedback Score: 0 reviews	SR bucking problem but no codes! I just swapped my redtop into another chassis and now the car starts bucking bad when i ease into the throttle, but it doesnt happen at wife open throttle.Mods are... redtop z32 maf(new) greddy fmic fujita intake (PoS) Walbro pump I put the boost back down to stock until i figure this out. The MAF is new as are the plugs and O2 sensor. The ECU is showing 55 no problems. I checked for boost leaks and intakes leaks and nothing. Anyone have similar issues or have had in the past i would greatly appreciate the help. Also the plugs are fine(beige color) and there was no fuel smell when i took them out.

08-26-2008, 09:46 AM	#8
0wn3r Zilvia Addict Join Date: Oct 2007 Location: CT Posts: 676 Trader Rating: (4) Feedback Score: 4 reviews	you recirculated or no? __________________ 97 240sx se

08-26-2008, 10:23 AM	#10
burnsauto Premium Member Join Date: Dec 2006 Location: 717, PA Age: 35 Posts: 3,153 Trader Rating: (5) Rides Gallery: burnsauto Feedback Score: 5 reviews	double check that maf/wiring..granted it may be new, but defects to happen. double check all the wiring you did..make sure nothing is loose, it really sounds like the maf is cutting out/not getting a signal. __________________

08-27-2008, 09:47 AM	#16
BiG MiKE86 Nissanaholic! Join Date: Mar 2007 Location: Ft. Lauderdale Age: 35 Posts: 1,776 Trader Rating: (12) Feedback Score: 12 reviews	sounds like u has a major vac. leak - ^^^ 0wn3r's numbers are what u should be reading - Goodluck __________________

08-27-2008, 10:44 AM	#17
DDSR240 Zilvia Member Join Date: Dec 2006 Location: South Carolina Age: 34 Posts: 259 Trader Rating: (0) Feedback Score: 0 reviews	damn I'm sorry bro I had that same problem and it turned out to be the fuel pump sock I know it sounds strange but try it. g/l __________________

08-26-2008, 07:25 AM	#2
Firestorm Zilvia Junkie Join Date: Sep 2007 Location: Germany Age: 34 Posts: 371 Trader Rating: (0) Feedback Score: 0 reviews	is your ECU mapped for the Z32 MAFS?

08-26-2008, 08:29 AM	#3
s13hatchback Join Date: Sep 2006 Location: Ramstein AB, Germany Age: 35 Posts: 22 Trader Rating: (0) Feedback Score: 0 reviews	its a stock #62 ecu

08-26-2008, 08:39 AM	#4
clark Zilvia FREAK! Join Date: Mar 2008 Location: new york Posts: 1,035 Trader Rating: (1) Feedback Score: 1 reviews	the #62 ecu is designed for a redtop SR MAF, not a z32 MAF. if your are using a Z32 MAF in an ecu that it was not dseigned for, you need some type of air/fuel controller like the ap;exi AFC, or a reflash of your ECU.. or get yourself the right MAF, or a SOHC KA24E maf.

08-26-2008, 08:48 AM	#5
s13hatchback Join Date: Sep 2006 Location: Ramstein AB, Germany Age: 35 Posts: 22 Trader Rating: (0) Feedback Score: 0 reviews	my bad thought i put that in there... i have an safc2

08-26-2008, 08:56 AM	#6
clark Zilvia FREAK! Join Date: Mar 2008 Location: new york Posts: 1,035 Trader Rating: (1) Feedback Score: 1 reviews	so did you configure the safc2 to compensate for the z32 maf? the settings are all over this forum.

08-26-2008, 09:21 AM	#7
HS13KLS Zilvia FREAK! Join Date: Aug 2006 Location: Illinois/California Age: 32 Posts: 1,114 Trader Rating: (13) Feedback Score: 13 reviews	i thought it was 2 in 10 out hot wire.. i may be wrong..but thats what i thought. check that out and see what happens

08-26-2008, 10:17 AM	#9
s13hatchback Join Date: Sep 2006 Location: Ramstein AB, Germany Age: 35 Posts: 22 Trader Rating: (0) Feedback Score: 0 reviews	no not recirc. it an hks ssqv

08-26-2008, 10:35 AM	#11
Black240Ct Zilvia Junkie Join Date: Sep 2003 Location: CT Age: 35 Posts: 563 Trader Rating: (6) Feedback Score: 6 reviews	check the voltages, im not sure if they are displayed on your safc, but get in there with a volt meter

08-26-2008, 12:38 PM	#12
s13hatchback Join Date: Sep 2006 Location: Ramstein AB, Germany Age: 35 Posts: 22 Trader Rating: (0) Feedback Score: 0 reviews	I believe it is displayed when you go to sensor check on the safc, though i dont know which one it is. If anyone does plz let me know... if it is sensor 1. it is at 1.1V at idle 2 is at .25 at idle

08-26-2008, 01:50 PM	#13
s13hatchback Join Date: Sep 2006 Location: Ramstein AB, Germany Age: 35 Posts: 22 Trader Rating: (0) Feedback Score: 0 reviews	like i said the car idles fine but when i give it slight throttle it starts cutting out and bucking. then when i get to about 3500 rpms it runs fin again under a decent amount of throttle

08-26-2008, 03:36 PM	#14
s13hatchback Join Date: Sep 2006 Location: Ramstein AB, Germany Age: 35 Posts: 22 Trader Rating: (0) Feedback Score: 0 reviews	I just spent a few hours checking everything and the maf reads 1.25V when at idle and the boost gauge sits at zero even when the car is at idle. when i give it gas it starts to read vacuum until i hit boost and it reads the boost just fine. Anyone have any other ideas?

08-27-2008, 11:06 AM	#18
GSXRJJordan Post Whore! Join Date: May 2006 Location: << 626 >> Posts: 9,135 Trader Rating: (19) Rides Gallery: GSXRJJordan Feedback Score: 19 reviews	Haha how can no one mention GROUNDS. Check your grounds, from the MAF to the body, from the ignition harness (coilpacks) to the head, to the body, and from the ECU to the body. That's much more likely to be the problem than SAFC settings, because your car idles correctly. __________________ Jordan Innovations has a new web site! www.JordanInnovations.com -- All your favorite FD Pro Drifters love it, trust me -- www.JordanInnovations.com

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