RB25 Injector Issues - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Brok3n_RB25 · 12-11-2010, 03:30 PM

Hey guys. I'm relatively new posting wise on this forum. I've trolled it for months now, but never really got active. I'm having an issue with my RB swap. I'm at the last leg of getting it running, but my injectors aren't firing. I've tried testing the CAS. I swapped it when one didn't work. Still no success. I've checked all the ground signal wires to the ECU. They're all good. They have power, but for some reason... they aren't getting the signal from the ECU to ground. I checked my ECCS relays even though I wasn't sure they had anything to do with the injector circuit. The injectors all ohm test good. My CEL is on with the key on, but turns off with cranking. So, that SHOULD be ok. Not 100%. Any help on where to look next would be appreciated. Thanks.

Sileighty_85 · 12-11-2010, 03:51 PM

you make it sound like the Injector Main harness isnt connected

Brok3n_RB25 · 12-11-2010, 05:38 PM

It's all connected. It's just not getting ground signal. I disconnected it to check for the +12v constant power and to check continuity to the ECU. Then, I reconnected it.

username · 12-12-2010, 01:15 AM

i just had this exact problem with my car and it can be 3 different things: fried injector driver in the ecu (bad ecu), bad injectors, or a bad injector harness. I ended up having a bad injector harness and 6, yes 6 bad injectors but somehow all my coils only ohmed out to .3-.6 so they were bad. You said you checked yours which leaves a bad ecu or bad injector harness. I have a spare good ecu if you need one.

Brok3n_RB25 · 12-12-2010, 01:42 AM

Send me a text. I think that the ECU might be the source of my problems.
8502187988. Casey

Brok3n_RB25 · 12-12-2010, 07:48 PM

Ok guys. I found a bad ground and fixed it. Now I'm having troubles with getting the car to fully fire up. It's sputtering and then dying. I'm thinking that the CAS needs to be timed for it to fire up. Any advice?

Brok3n_RB25 · 12-13-2010, 12:09 AM

Alright. Narrowed it down to the MAF. For some reason the signal wire is showing 9.5v. With the MAF unplugged it starts, but it idles like shit. I tested the MAF off the car with the 12v FSM test. It gets like 300mv on the signal wire. How the f***? bad MAF?

modulation · 12-17-2010, 02:45 PM

Quote:

Originally Posted by Brok3n_RB25

Alright. Narrowed it down to the MAF. For some reason the signal wire is showing 9.5v. With the MAF unplugged it starts, but it idles like shit. I tested the MAF off the car with the 12v FSM test. It gets like 300mv on the signal wire. How the f***? bad MAF?

Signal from MAF should be 0-5v.
Are you sure you have the correct wiring harness/pinout matched?

12-11-2010, 03:30 PM	#1
Brok3n_RB25 Join Date: Dec 2009 Location: Northwest Florida Posts: 48 Trader Rating: (0) Feedback Score: 0 reviews	RB25 Injector Issues Hey guys. I'm relatively new posting wise on this forum. I've trolled it for months now, but never really got active. I'm having an issue with my RB swap. I'm at the last leg of getting it running, but my injectors aren't firing. I've tried testing the CAS. I swapped it when one didn't work. Still no success. I've checked all the ground signal wires to the ECU. They're all good. They have power, but for some reason... they aren't getting the signal from the ECU to ground. I checked my ECCS relays even though I wasn't sure they had anything to do with the injector circuit. The injectors all ohm test good. My CEL is on with the key on, but turns off with cranking. So, that SHOULD be ok. Not 100%. Any help on where to look next would be appreciated. Thanks.

12-11-2010, 03:51 PM	#2
Sileighty_85 Post Whore! Join Date: Dec 2006 Location: Misawa, Japan Posts: 6,815 Trader Rating: (8) Feedback Score: 8 reviews	you make it sound like the Injector Main harness isnt connected __________________ 後輪駆動車１番 1989 Built SR GT2871R -363whp 1998 S14 W/RB25- 250ish (For Now) 1986 SR86 - 200ish 1990 R32 GTR - 320hp Don't Buy Engines from JDM-Online http://zilvia.net/f/businesses/207457-jdm-online.html Don't Buy XS-Power or SSAC Shit

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12-11-2010, 05:38 PM	#3
Brok3n_RB25 Join Date: Dec 2009 Location: Northwest Florida Posts: 48 Trader Rating: (0) Feedback Score: 0 reviews	It's all connected. It's just not getting ground signal. I disconnected it to check for the +12v constant power and to check continuity to the ECU. Then, I reconnected it.

12-12-2010, 01:15 AM	#4
username Zilvia Member Join Date: Sep 2008 Location: Florida Age: 31 Posts: 207 Trader Rating: (5) Feedback Score: 5 reviews	i just had this exact problem with my car and it can be 3 different things: fried injector driver in the ecu (bad ecu), bad injectors, or a bad injector harness. I ended up having a bad injector harness and 6, yes 6 bad injectors but somehow all my coils only ohmed out to .3-.6 so they were bad. You said you checked yours which leaves a bad ecu or bad injector harness. I have a spare good ecu if you need one.

12-12-2010, 01:42 AM	#5
Brok3n_RB25 Join Date: Dec 2009 Location: Northwest Florida Posts: 48 Trader Rating: (0) Feedback Score: 0 reviews	Send me a text. I think that the ECU might be the source of my problems. 8502187988. Casey

12-12-2010, 07:48 PM	#6
Brok3n_RB25 Join Date: Dec 2009 Location: Northwest Florida Posts: 48 Trader Rating: (0) Feedback Score: 0 reviews	Ok guys. I found a bad ground and fixed it. Now I'm having troubles with getting the car to fully fire up. It's sputtering and then dying. I'm thinking that the CAS needs to be timed for it to fire up. Any advice?

12-13-2010, 12:09 AM	#7
Brok3n_RB25 Join Date: Dec 2009 Location: Northwest Florida Posts: 48 Trader Rating: (0) Feedback Score: 0 reviews	Alright. Narrowed it down to the MAF. For some reason the signal wire is showing 9.5v. With the MAF unplugged it starts, but it idles like shit. I tested the MAF off the car with the 12v FSM test. It gets like 300mv on the signal wire. How the f***? bad MAF?