rb25det neo s13 sputter/hesitation - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Mzag · 04-22-2015, 09:48 PM

hey guys, i know there are a ton of threads about rb25 sputter issues but non have helped me solve my problem. Heres what its doing, under light acceleration, anything below 1/2 throttle, it feels normal other than running really rich(high 9s low 10s). As soon as I go wot, doesnt matter what rpm im at, it will clime maybe 1-2k rpm and then just cut out. Not exactly sure how to describe it but its an abrupt stop, rpm will drop, goes full lean like Im letting off the throttle. Maybe a maf cut? Fuel cut? Heres what I have:
rb25det neo
stock ecu
stock turbo
3" turbo back exhaust
fmic
greddy knock off intake mani
stock coilpacks, ngk bcpr6es plugs

I have already swapped the maf, coilpacks with liquid electrical tape, gapped the plugs smaller, set timing at 15 degrees at 650rpm, set tps to .5v closed, I have not got around to doing a boost leak test but im almost sure there arent any.

Anyways, im at a complete loss with this issue, any advice is greatly appreciated.

Mzag · 04-22-2015, 09:51 PM

also forgot to mention fpr is set to 43 psi without vacuum, 36-38 with. I also have a consult cable connected to my tablet and all sensors seem to be working properly but if someone could give me a rundown of what each should be running at that would be great

mixeds14 · 04-25-2015, 10:27 PM

Just wondering, what are u using for fuel pump. U didn't mention that..
Also if ur running 9-10 afrs under half throttle that is way to rich and u might just foul your plugs within time. I mean at wot your afrs should be low 11 to high 10s on a stock ecu or afthermarket one or u will have some sputtering at wot with those afrs being to rich.

Check your knock sensors btw, my neo knock sensor harness keep coming loose and it would give me different symptoms at times.just trowing that out there..

G-E@Z31P · 04-25-2015, 10:34 PM

Maybe got the wrong injectors in there like from a regular rb25det?

Mzag · 04-26-2015, 09:13 AM

Thanks for the replys. Ya forgot to mention the fuel pump, it's an Isis 255 which I know isn't ideal but that what came with the car. I'm gonna check leaky injectors today, also I am using 370cc injectors from s1/s2, I couldn't find much info on stock neo injectors and some people say they are 340s and some say 370s, would that cause that much of an issue? As far as the knock sensors, they are not throwing any codes in the consult, if they were bad would it say so when idling or should I check while I'm driving and when the sputtering occurs?

Mzag · 04-26-2015, 09:14 AM

I can also try using the data logging in the consult and see what's happening while driving. I'm yet to mess around with that but maybe it would tell me more than I can monitor in the car

Ilya · 04-26-2015, 10:38 AM

^yes data log your issue if you can and post it up so we can see

G-E@Z31P · 04-26-2015, 11:44 AM

Yes the non-NEO injectors are about 10% larger, so that would be the likely cause of your trouble...

I have a set of low-mile NEO injectors I'm not using (pm if you are interested)

Mzag · 04-26-2015, 08:35 PM

Quote:

Originally Posted by G-E@Z31P

Yes the non-NEO injectors are about 10% larger, so that would be the likely cause of your trouble...

I have a set of low-mile NEO injectors I'm not using (pm if you are interested)

Sounds good, I'll let ya know what I come up with.

I worked on it some this afternoon and did a boost leak check. Embarrassingly enough I had a pretty good leak out the injector insulators, the rubber grommets between the injectors and intake mani. So I ordered some of those and should get them in tmrw. I'll report back tmrw with any updates, and thanks for the help guys.

MADE · 04-26-2015, 09:04 PM

I didn't know you could use Series 1/2 inj on a NEO which are Top mount correct.

Mzag · 04-26-2015, 09:09 PM

Correct, they are top mount from the factory. I have a front facing intake mani so it has s1/2 inj with the s1/2 fuel rail which was put in by the previous owner. I could get a top mount rail with neo injectors and it should bolt up, just making 100% sure I have to go that route before spending the cash

Mzag · 04-28-2015, 09:41 PM

Alright, so I got the injector insulators installed and that made a major difference. With those in I was able to do a true boost leak test since it will actually hold pressure now and I still have a few small leaks at some couplers. Hopefully once those are taken care of it will be good to go

04-22-2015, 09:48 PM	#1
Mzag Leaky Injector Join Date: Sep 2012 Location: Maine Age: 32 Posts: 95 Trader Rating: (1) Feedback Score: 1 reviews	rb25det neo s13 sputter/hesitation hey guys, i know there are a ton of threads about rb25 sputter issues but non have helped me solve my problem. Heres what its doing, under light acceleration, anything below 1/2 throttle, it feels normal other than running really rich(high 9s low 10s). As soon as I go wot, doesnt matter what rpm im at, it will clime maybe 1-2k rpm and then just cut out. Not exactly sure how to describe it but its an abrupt stop, rpm will drop, goes full lean like Im letting off the throttle. Maybe a maf cut? Fuel cut? Heres what I have: rb25det neo stock ecu stock turbo 3" turbo back exhaust fmic greddy knock off intake mani stock coilpacks, ngk bcpr6es plugs I have already swapped the maf, coilpacks with liquid electrical tape, gapped the plugs smaller, set timing at 15 degrees at 650rpm, set tps to .5v closed, I have not got around to doing a boost leak test but im almost sure there arent any. Anyways, im at a complete loss with this issue, any advice is greatly appreciated.

04-25-2015, 10:34 PM	#4
G-E@Z31P Leaky Injector Join Date: Sep 2012 Location: Toronto Posts: 126 Trader Rating: (0) Feedback Score: 0 reviews	Maybe got the wrong injectors in there like from a regular rb25det? __________________

04-26-2015, 11:44 AM	#8
G-E@Z31P Leaky Injector Join Date: Sep 2012 Location: Toronto Posts: 126 Trader Rating: (0) Feedback Score: 0 reviews	Yes the non-NEO injectors are about 10% larger, so that would be the likely cause of your trouble... I have a set of low-mile NEO injectors I'm not using (pm if you are interested) __________________

04-26-2015, 09:04 PM	#10
MADE Zilvia Addict Join Date: Jan 2006 Location: Norf Norf Posts: 974 Trader Rating: (1) Feedback Score: 1 reviews	I didn't know you could use Series 1/2 inj on a NEO which are Top mount correct. __________________

04-22-2015, 09:51 PM	#2
Mzag Leaky Injector Join Date: Sep 2012 Location: Maine Age: 32 Posts: 95 Trader Rating: (1) Feedback Score: 1 reviews	also forgot to mention fpr is set to 43 psi without vacuum, 36-38 with. I also have a consult cable connected to my tablet and all sensors seem to be working properly but if someone could give me a rundown of what each should be running at that would be great

04-25-2015, 10:27 PM	#3
mixeds14 Leaky Injector Join Date: Jan 2010 Location: nc Posts: 71 Trader Rating: (2) Feedback Score: 2 reviews	Just wondering, what are u using for fuel pump. U didn't mention that.. Also if ur running 9-10 afrs under half throttle that is way to rich and u might just foul your plugs within time. I mean at wot your afrs should be low 11 to high 10s on a stock ecu or afthermarket one or u will have some sputtering at wot with those afrs being to rich. Check your knock sensors btw, my neo knock sensor harness keep coming loose and it would give me different symptoms at times.just trowing that out there..

04-26-2015, 09:13 AM	#5
Mzag Leaky Injector Join Date: Sep 2012 Location: Maine Age: 32 Posts: 95 Trader Rating: (1) Feedback Score: 1 reviews	Thanks for the replys. Ya forgot to mention the fuel pump, it's an Isis 255 which I know isn't ideal but that what came with the car. I'm gonna check leaky injectors today, also I am using 370cc injectors from s1/s2, I couldn't find much info on stock neo injectors and some people say they are 340s and some say 370s, would that cause that much of an issue? As far as the knock sensors, they are not throwing any codes in the consult, if they were bad would it say so when idling or should I check while I'm driving and when the sputtering occurs?

04-26-2015, 09:14 AM	#6
Mzag Leaky Injector Join Date: Sep 2012 Location: Maine Age: 32 Posts: 95 Trader Rating: (1) Feedback Score: 1 reviews	I can also try using the data logging in the consult and see what's happening while driving. I'm yet to mess around with that but maybe it would tell me more than I can monitor in the car

04-26-2015, 10:38 AM	#7
Ilya Zilvia Addict Join Date: Jan 2008 Location: San Diego Age: 35 Posts: 712 Trader Rating: (2) Feedback Score: 2 reviews	^yes data log your issue if you can and post it up so we can see

04-26-2015, 09:09 PM	#11
Mzag Leaky Injector Join Date: Sep 2012 Location: Maine Age: 32 Posts: 95 Trader Rating: (1) Feedback Score: 1 reviews	Correct, they are top mount from the factory. I have a front facing intake mani so it has s1/2 inj with the s1/2 fuel rail which was put in by the previous owner. I could get a top mount rail with neo injectors and it should bolt up, just making 100% sure I have to go that route before spending the cash

04-28-2015, 09:41 PM	#12
Mzag Leaky Injector Join Date: Sep 2012 Location: Maine Age: 32 Posts: 95 Trader Rating: (1) Feedback Score: 1 reviews	Alright, so I got the injector insulators installed and that made a major difference. With those in I was able to do a true boost leak test since it will actually hold pressure now and I still have a few small leaks at some couplers. Hopefully once those are taken care of it will be good to go