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

SLEEPERracer · 04-16-2008, 03:44 AM

was wondering if you guys have any idea y an sr would studder? it was running fine and its all stock except for front mount and bov. well it only studders when i hit boost. like it lacks fuel or something. only thing that was changed was the previous owner switching out the ecu for another, and ever since then had the this problem. any help would be greatly appriciated. thanks in advance.

IRN · 04-16-2008, 03:51 AM

if it happened right after the ecu swap then try swapping the ecu to a known good one lol

ocn · 04-16-2008, 04:24 AM

do you have a walrbo fuel pump if not thats your problem, also chek you vacum lines.

AllMotorS13 · 04-16-2008, 03:21 PM

how would a fuel pump make it stutter? i'm assuming your on stock boost if you don't have a walbro. the ka pump can handle stock boost. change the ecu first, obviously. if that doesn't do it, check for boost/vacuum leaks. do the tap test on your MAF and wiring. try unplugging the O2 sensor and see if it goes away (that's what mine was). plugs in good condition? coils may be suspect. there's a ton of reasons for a stutter under boost. does it do it under full throttle, partial throttle? Engine cold or warmed up?

Z33dori · 04-16-2008, 03:24 PM

yea my car is having this trouble too.....

as soon as it starts hitting boost it would start sputtering and breaking up...i thought it was coil pack or spark plug but i have changed out both so its niether of those, so my next beat im guessing is to try and get a another ecu? fuck

AllMotorS13 · 04-16-2008, 03:26 PM

Quote:

Originally Posted by Z33dori

yea my car is having this trouble too.....

as soon as it starts hitting boost it would start sputtering and breaking up...i thought it was coil pack or spark plug but i have changed out both so its niether of those, so my next beat im guessing is to try and get a another ecu? fuck

read my post above. i just diag'd this on my own car. my ECU was fine.

Mi Beardo es Loco · 04-16-2008, 03:35 PM

I would check the MAF. I've come across a rash of bad MAF's lately. Just a hunch.

BeasT_MoDe · 04-20-2008, 09:48 AM

sounds like a boost leak.

deuceforty · 04-20-2008, 10:09 AM

ive got a buddy who is having this same problem...

his is a bit different though, its a completely stock SR, sidemount, stock diverter valve etc.

hes ran through the entire wiring harness, changed the TPS, plugs, maf and a few other things.

when his car starts, he will have 3-4 good pulls, then it will start to stutter at boost. heres the catch, if you turn it off, then back on, you will get 1-2 more good pulls.

here is yet ANOTHER catch.

car will build full boost in neutral. you can sit with the car in neutral, rev it, and boost will build to 10psi... how can it boost if there is virtually no load on the engine?

its got us stumped

04-16-2008, 03:44 AM	#1
SLEEPERracer Leaky Injector Join Date: May 2005 Location: An Island Posts: 126 Trader Rating: (0) Feedback Score: 0 reviews	sr stuttering was wondering if you guys have any idea y an sr would studder? it was running fine and its all stock except for front mount and bov. well it only studders when i hit boost. like it lacks fuel or something. only thing that was changed was the previous owner switching out the ecu for another, and ever since then had the this problem. any help would be greatly appriciated. thanks in advance.

04-16-2008, 03:51 AM	#2
IRN Leaky Injector Join Date: Nov 2007 Location: land of the refs Age: 36 Posts: 130 Trader Rating: (0) Feedback Score: 0 reviews	if it happened right after the ecu swap then try swapping the ecu to a known good one lol __________________

04-16-2008, 03:21 PM	#4
AllMotorS13 Join Date: Nov 2006 Location: South Carolina Age: 40 Posts: 24 Trader Rating: (0) Feedback Score: 0 reviews	how would a fuel pump make it stutter? i'm assuming your on stock boost if you don't have a walbro. the ka pump can handle stock boost. change the ecu first, obviously. if that doesn't do it, check for boost/vacuum leaks. do the tap test on your MAF and wiring. try unplugging the O2 sensor and see if it goes away (that's what mine was). plugs in good condition? coils may be suspect. there's a ton of reasons for a stutter under boost. does it do it under full throttle, partial throttle? Engine cold or warmed up? __________________ 89' Two Tone - All Original

04-16-2008, 03:24 PM	#5
Z33dori Post Whore! Join Date: Dec 2006 Location: Riverview, FL Age: 35 Posts: 5,557 Trader Rating: (12) Feedback Score: 12 reviews	yea my car is having this trouble too..... as soon as it starts hitting boost it would start sputtering and breaking up...i thought it was coil pack or spark plug but i have changed out both so its niether of those, so my next beat im guessing is to try and get a another ecu? fuck __________________

04-16-2008, 04:24 AM	#3
ocn Zilvia Member Join Date: Apr 2008 Location: Arkansas Age: 38 Posts: 198 Trader Rating: (0) Feedback Score: 0 reviews	do you have a walrbo fuel pump if not thats your problem, also chek you vacum lines.

04-16-2008, 03:35 PM	#7
Mi Beardo es Loco Nissanaholic! Join Date: Mar 2008 Location: A place where boob jobs ruined the best thing about being a fat chick. Posts: 1,774 Trader Rating: (0) Feedback Score: 0 reviews	I would check the MAF. I've come across a rash of bad MAF's lately. Just a hunch.

04-20-2008, 09:48 AM	#8
BeasT_MoDe Zilvia Junkie Join Date: Sep 2007 Location: Orange County Posts: 351 Trader Rating: (5) Feedback Score: 5 reviews	sounds like a boost leak.

04-20-2008, 10:09 AM	#9
deuceforty Zilvia Addict Join Date: Apr 2008 Location: raleigh Age: 36 Posts: 907 Trader Rating: (12) Feedback Score: 12 reviews	ive got a buddy who is having this same problem... his is a bit different though, its a completely stock SR, sidemount, stock diverter valve etc. hes ran through the entire wiring harness, changed the TPS, plugs, maf and a few other things. when his car starts, he will have 3-4 good pulls, then it will start to stutter at boost. heres the catch, if you turn it off, then back on, you will get 1-2 more good pulls. here is yet ANOTHER catch. car will build full boost in neutral. you can sit with the car in neutral, rev it, and boost will build to 10psi... how can it boost if there is virtually no load on the engine? its got us stumped