S14 sr20det studdering - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

starion1991 · 02-02-2014, 12:38 AM

Hello guys, having a weird issue with my car. I've tried quite a few things to figure out the issue and I've searched as well but haven't been on the lucky side sooooo here I am

Info on the car- 94 s13 vert with s14 notch top sr, walbro 255, 790cc n62 maf, jim wolf rom tune, top mount gt3076, stock internals,

What it's doing- about 2 months ago, I was at a buddy's house, drove home fine, ran and boosted as it normally dose. Got home and parked it for a while while I was looking for a set of tires. It sat about 2 months, finally got a new pair of tires and decided to take it out. It started up ok, ran rough. So I let it idle for a while to get it warmed up and it died. Cranked it and it fired up again. I tried to rev it and it would go to about 1500ish rpm and bounce around like it hit a ignition cut. So I kept playing around with it and occasionally I could get it over the 1500 rpm mark but it ran choppy and revved slowly, best way to discribe it it basically sounded like a sti or subie revving. I spent all afternoon messing with it, started by unplugging the cts, it ran a lot better and revved fine so I went out and got a autozone cts, toss it in and the issue is back, I try a set of new plugs, a good set of coil packs and harness, a good ignighter, new fuel filter, a good z32 maf, exc...exc... No positive results. It dose run a lot better with the cts unplugged but not good enough to drive on main roads. With the cts unplugged sometimes it will run perfect until 4500ish rpm, then it just won't go into boost and will start spuddering/ let out a big ol pop. Any ideas? I've tried about everything I can think of.

Also, this may be unrelated but it may not be helping the issue. When the car ran perfect I would always have to pump the throttle while cranking the engine to get it started. I've always had to do this to get the car started and still have to do it now with the issue I am having. Any suggestions would be appreciated. Thanks!

Sorry for the shitty grammar/ spelling, typing on a iPad sucks!

emu103 · 02-02-2014, 12:56 AM

Knock sensor is a possibility. Look into my old threads on how to troubleshoot. Pm me if you need more info

Sent from my SCH-I535 using Tapatalk 2

starion1991 · 02-02-2014, 01:43 AM

Links please!

emu103 · 02-02-2014, 02:23 AM

Its in my old topics look in my profile. I'm on a phone via tapatalk

Sent from my SCH-I535 using Tapatalk 2

jerry_beans · 02-02-2014, 03:56 AM

Check all your coil packs. One of mine was cracked and made the same boxer noise

rotation3x · 02-03-2014, 06:21 PM

check for spark. if you have spark go to next step.
1.disconnect coil pack harness
2.Pull upper section of intake manifold off.
3.remove fuel rail with injectors and plugs attached.
4.pull rail back and put a piece of triple layered paper towels in front of injectors
5.double check coil pack harness is disconnected.
6.turn key to on see if any O-rings are leaking.
7.crank engine over.
8. look at the paper towel and see if all injectors look like they sprayed the same amount of fuel.

I had a misfire issue messing with me for a while it was a injector.

KevinEdgar · 02-04-2014, 01:23 PM

Redo your timing, my s14 sr did the same slow revving subie sound thing.

Zbythegods · 02-04-2014, 05:35 PM

Any possibility that this may be a fuel issue? We all know how those Walboros like acting up on us from time to time.

02-02-2014, 12:38 AM	#1
starion1991 Join Date: Mar 2009 Location: Phoenix az Age: 32 Posts: 31 Trader Rating: (2) Feedback Score: 2 reviews	S14 sr20det studdering Hello guys, having a weird issue with my car. I've tried quite a few things to figure out the issue and I've searched as well but haven't been on the lucky side sooooo here I am Info on the car- 94 s13 vert with s14 notch top sr, walbro 255, 790cc n62 maf, jim wolf rom tune, top mount gt3076, stock internals, What it's doing- about 2 months ago, I was at a buddy's house, drove home fine, ran and boosted as it normally dose. Got home and parked it for a while while I was looking for a set of tires. It sat about 2 months, finally got a new pair of tires and decided to take it out. It started up ok, ran rough. So I let it idle for a while to get it warmed up and it died. Cranked it and it fired up again. I tried to rev it and it would go to about 1500ish rpm and bounce around like it hit a ignition cut. So I kept playing around with it and occasionally I could get it over the 1500 rpm mark but it ran choppy and revved slowly, best way to discribe it it basically sounded like a sti or subie revving. I spent all afternoon messing with it, started by unplugging the cts, it ran a lot better and revved fine so I went out and got a autozone cts, toss it in and the issue is back, I try a set of new plugs, a good set of coil packs and harness, a good ignighter, new fuel filter, a good z32 maf, exc...exc... No positive results. It dose run a lot better with the cts unplugged but not good enough to drive on main roads. With the cts unplugged sometimes it will run perfect until 4500ish rpm, then it just won't go into boost and will start spuddering/ let out a big ol pop. Any ideas? I've tried about everything I can think of. Also, this may be unrelated but it may not be helping the issue. When the car ran perfect I would always have to pump the throttle while cranking the engine to get it started. I've always had to do this to get the car started and still have to do it now with the issue I am having. Any suggestions would be appreciated. Thanks! Sorry for the shitty grammar/ spelling, typing on a iPad sucks! Last edited by starion1991; 02-02-2014 at 12:40 AM.. Reason: Spelling error

02-02-2014, 03:56 AM	#5
jerry_beans Zilvia FREAK! Join Date: Oct 2011 Location: El Paso Tejas Posts: 1,006 Trader Rating: (27) Feedback Score: 27 reviews	Check all your coil packs. One of mine was cracked and made the same boxer noise __________________ IG @jerry_beans_

02-04-2014, 01:23 PM	#7
KevinEdgar Zilvia FREAK! Join Date: Jan 2011 Location: osaka, japan Posts: 1,176 Trader Rating: (19) Feedback Score: 19 reviews	Redo your timing, my s14 sr did the same slow revving subie sound thing. __________________ http://milktea-man.com

02-02-2014, 12:56 AM	#2
emu103 Zilvia Member Join Date: Mar 2009 Location: nc Age: 34 Posts: 185 Trader Rating: (4) Feedback Score: 4 reviews	Knock sensor is a possibility. Look into my old threads on how to troubleshoot. Pm me if you need more info Sent from my SCH-I535 using Tapatalk 2

02-02-2014, 01:43 AM	#3
starion1991 Join Date: Mar 2009 Location: Phoenix az Age: 32 Posts: 31 Trader Rating: (2) Feedback Score: 2 reviews	Links please!

02-02-2014, 02:23 AM	#4
emu103 Zilvia Member Join Date: Mar 2009 Location: nc Age: 34 Posts: 185 Trader Rating: (4) Feedback Score: 4 reviews	Its in my old topics look in my profile. I'm on a phone via tapatalk Sent from my SCH-I535 using Tapatalk 2

02-03-2014, 06:21 PM	#6
rotation3x Zilvia Member Join Date: Jun 2005 Location: virginia Age: 38 Posts: 272 Trader Rating: (2) Feedback Score: 2 reviews	check for spark. if you have spark go to next step. 1.disconnect coil pack harness 2.Pull upper section of intake manifold off. 3.remove fuel rail with injectors and plugs attached. 4.pull rail back and put a piece of triple layered paper towels in front of injectors 5.double check coil pack harness is disconnected. 6.turn key to on see if any O-rings are leaking. 7.crank engine over. 8. look at the paper towel and see if all injectors look like they sprayed the same amount of fuel. I had a misfire issue messing with me for a while it was a injector.

02-04-2014, 05:35 PM	#8
Zbythegods Zilvia Member Join Date: May 2013 Location: Tampa Age: 33 Posts: 238 Trader Rating: (4) Feedback Score: 4 reviews	Any possibility that this may be a fuel issue? We all know how those Walboros like acting up on us from time to time.