RB20 dies when maf plugged in! But maf is good - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

fearlessKouki · 10-07-2013, 12:50 PM

Hey Everyone,
I am having issues with my rb20 swap in a 1997 s14. The car runs and idles well when unplugged from maf but as soon MAF is plugged in it bogs out and dies.
I tested the MAF and ECU with my friends car with rb20det and they ran great. I have checked about everything, i am thinking that something is wrong with wiring now.

I got the brand new harness from Wiring Specialties, i previously had problem with harness as number 1 coil was getting hot. I talked to Yury and he had me cut a wire from the harness. After that no more issues and i was getting spark.

So i am not too positive how the wiring harness is as i had some issue previously with it. I contacted them but haven't gotten a response back yet.
What do you guys suggest to check?

G5SR20240 · 10-07-2013, 01:48 PM

vacuum leak, a big one

fearlessKouki · 10-07-2013, 03:02 PM

Im gonna try to find one using starter fluid tonight. will post up if i find anything.
Thanks for reply!

fearlessKouki · 10-07-2013, 08:17 PM

Okay so tested for vaccum leaks but didn't find any. so any more suggestions are appreciated thanks!

*wangan_cruiser* · 10-07-2013, 08:18 PM

Definitely a vacuum leak

JesterX18 · 10-07-2013, 08:46 PM

I having the same problem with my SR with the wiring specialties harness. Runs smooth when you unplug maf but as soon as you plug it in sputters and dies.... Im running a z32 MAF in my set up. If yours is a Z32(you didn't specify) Id suggest making sure you've got 12 volts on power. (black/white) A Good ground reading at the two middle wires. Black and Green I believe... And then you should have just over a volt at idle on the 4th wire(red I believe).All measurements made with connector plugged in and key on except the signal wire(4th wire) which is measured when car is idling. I just tested mine tonight.... Ive heard that if you have a crappy ground on the Z32 it will run real rich. I cant verify cause mines running like crap all the time..... I think my issue is Jim Wolfe mistuned my ECU for the wrong MAF. Yours sounds like wiring since you swapped parts in a known good car... Good Luck...

fearlessKouki · 10-08-2013, 05:33 AM

its a stock j60 maf I am getting power 12.4~ Volts and getting ground continuity on the ground wire. I haven't tested signal wire as it dies right after you plug in maf.

I can go over the vacuum leak one more time and see if i find anything.

thanks

fearlessKouki · 10-08-2013, 05:29 PM

can't seem to find any leak, im using using starter fluid to test for leaks but im getting nothing.

OnTheChip · 10-09-2013, 08:18 AM

Sure sounds like a wiring problem between the MAF and ECU.

fearlessKouki · 10-13-2013, 08:28 PM

okay so this is weird. I switched up the signal and ground for MAF on ecu plug. and then it would start with maf connected. but would not rev past 3800-4000 RPM. Now the weird thing is that before i switched them they were on the right way. meaning pin #26 ground and pin # 27 signal. So not sure what is going on with this. any input?

Jdmsilivias13 · 10-13-2013, 10:23 PM

Boost leak bro

fearlessKouki · 10-14-2013, 01:04 PM

I smoke tested the intake manifold found no leaks. all intake pipes are secured tightly. boost leak still does'nt explain the switching of maf ground and signal situation i posted above your comment @jdmsilvias13

10-07-2013, 12:50 PM	#1
fearlessKouki Zilvia Member Join Date: Oct 2010 Location: Ohio Age: 32 Posts: 279 Trader Rating: (2) Feedback Score: 2 reviews	RB20 dies when maf plugged in! But maf is good Hey Everyone, I am having issues with my rb20 swap in a 1997 s14. The car runs and idles well when unplugged from maf but as soon MAF is plugged in it bogs out and dies. I tested the MAF and ECU with my friends car with rb20det and they ran great. I have checked about everything, i am thinking that something is wrong with wiring now. I got the brand new harness from Wiring Specialties, i previously had problem with harness as number 1 coil was getting hot. I talked to Yury and he had me cut a wire from the harness. After that no more issues and i was getting spark. So i am not too positive how the wiring harness is as i had some issue previously with it. I contacted them but haven't gotten a response back yet. What do you guys suggest to check?

10-09-2013, 08:18 AM	#9
OnTheChip Zilvia Junkie Join Date: May 2013 Location: Burgaw, NC Posts: 317 Trader Rating: (0) Feedback Score: 0 reviews	Sure sounds like a wiring problem between the MAF and ECU. __________________ NismotronicSA - Speed-Density Tuning for Nissans

10-07-2013, 01:48 PM	#2
G5SR20240 Zilvia Member Join Date: Jan 2011 Location: San Diego Age: 39 Posts: 230 Trader Rating: (9) Feedback Score: 9 reviews	vacuum leak, a big one

10-07-2013, 03:02 PM	#3
fearlessKouki Zilvia Member Join Date: Oct 2010 Location: Ohio Age: 32 Posts: 279 Trader Rating: (2) Feedback Score: 2 reviews	Im gonna try to find one using starter fluid tonight. will post up if i find anything. Thanks for reply!

10-07-2013, 08:17 PM	#4
fearlessKouki Zilvia Member Join Date: Oct 2010 Location: Ohio Age: 32 Posts: 279 Trader Rating: (2) Feedback Score: 2 reviews	Okay so tested for vaccum leaks but didn't find any. so any more suggestions are appreciated thanks!

10-07-2013, 08:18 PM	#5
wangan_cruiser kouki man Join Date: Apr 2006 Location: downtown oakland,ca Age: 39 Posts: 3,535 Trader Rating: (36) Feedback Score: 36 reviews	Definitely a vacuum leak

10-07-2013, 08:46 PM	#6
JesterX18 Join Date: Feb 2013 Location: Clifton Park, NY Age: 34 Posts: 34 Trader Rating: (2) Feedback Score: 2 reviews	I having the same problem with my SR with the wiring specialties harness. Runs smooth when you unplug maf but as soon as you plug it in sputters and dies.... Im running a z32 MAF in my set up. If yours is a Z32(you didn't specify) Id suggest making sure you've got 12 volts on power. (black/white) A Good ground reading at the two middle wires. Black and Green I believe... And then you should have just over a volt at idle on the 4th wire(red I believe).All measurements made with connector plugged in and key on except the signal wire(4th wire) which is measured when car is idling. I just tested mine tonight.... Ive heard that if you have a crappy ground on the Z32 it will run real rich. I cant verify cause mines running like crap all the time..... I think my issue is Jim Wolfe mistuned my ECU for the wrong MAF. Yours sounds like wiring since you swapped parts in a known good car... Good Luck...

10-08-2013, 05:33 AM	#7
fearlessKouki Zilvia Member Join Date: Oct 2010 Location: Ohio Age: 32 Posts: 279 Trader Rating: (2) Feedback Score: 2 reviews	its a stock j60 maf I am getting power 12.4~ Volts and getting ground continuity on the ground wire. I haven't tested signal wire as it dies right after you plug in maf. I can go over the vacuum leak one more time and see if i find anything. thanks

10-08-2013, 05:29 PM	#8
fearlessKouki Zilvia Member Join Date: Oct 2010 Location: Ohio Age: 32 Posts: 279 Trader Rating: (2) Feedback Score: 2 reviews	can't seem to find any leak, im using using starter fluid to test for leaks but im getting nothing.

10-13-2013, 08:28 PM	#10
fearlessKouki Zilvia Member Join Date: Oct 2010 Location: Ohio Age: 32 Posts: 279 Trader Rating: (2) Feedback Score: 2 reviews	okay so this is weird. I switched up the signal and ground for MAF on ecu plug. and then it would start with maf connected. but would not rev past 3800-4000 RPM. Now the weird thing is that before i switched them they were on the right way. meaning pin #26 ground and pin # 27 signal. So not sure what is going on with this. any input?

10-13-2013, 10:23 PM	#11
Jdmsilivias13 Leaky Injector Join Date: Jan 2013 Location: West Chester pa Age: 36 Posts: 68 Trader Rating: (2) Feedback Score: 2 reviews	Boost leak bro

10-14-2013, 01:04 PM	#12
fearlessKouki Zilvia Member Join Date: Oct 2010 Location: Ohio Age: 32 Posts: 279 Trader Rating: (2) Feedback Score: 2 reviews	I smoke tested the intake manifold found no leaks. all intake pipes are secured tightly. boost leak still does'nt explain the switching of maf ground and signal situation i posted above your comment @jdmsilvias13