Injector power wire, where is it?? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

invain · 01-01-2009, 12:41 PM

I'm getting low voltage at the injector plugs, low enough for one cylinder to not fire at all. After checking everything else possible I'm pretty much 100% sure there's a bad connection where the main power line splits off to the 4 seperate injector wires. I just need to know where these connections are. I figure the main power wire splits off somewhere in the harness farily close to the injectors, but I wanted to make sure it's not some where else before I tear the harness apart.

reinvent · 01-01-2009, 01:17 PM

mind reader i must be.

invain · 01-01-2009, 01:23 PM

I know how the ecu grounds the injectors. All I need to find is the connection for the 12 volt source.

Where is this relay? Fuse box in the engine bay or down under the dash on the drivers side?

reinvent · 01-01-2009, 01:29 PM

cool. glad you know what you are doing.

invain · 01-01-2009, 04:03 PM

Well, we fixed the voltage problem, there was a short in the power wire for that injector and the connection back in the harness was pretty shitty too. 12 volts at the injector plug now, but it's still not firing. We've checked continuity for the ground wire back to the ecu for that cylinder and it was fine. We've tried 2 different ecu's as well to rule that out.

Now I'm back to thinking it's the CAS. However, I can't find any diagrams that show exactly which wires are for which cylinders. If anybody knows that'd be awsome.

Rayne · 01-01-2009, 06:25 PM

Got a copy of the FSM?

invain · 01-01-2009, 06:57 PM

Yeah just ran through the guide in the fsm and checked all the connections. No dice.

At this point I have no clue wtf is going on unless the cas is bad.

Can a malfunctioning cam position sensor cause only one cylinder to misfire? We checked all connections to the cas according to the fsm. We checked all connections to the injector. Fixed a small short in the power wire to injector 2 so it now shows the correct 12 volts. We've used two different ecu's with no change in cylinder 2.

projectRDM · 01-01-2009, 07:07 PM

Stupid question, but did you swap the injector? Try swapping plugs from another injector that you know is good, plug it in to the questionable one.

invain · 01-02-2009, 09:28 AM

Yep we've already tried swapping injectors.

89dc240 · 02-16-2009, 07:05 AM

You figure this out?

01-01-2009, 12:41 PM	#1
invain Join Date: Jul 2008 Location: Michigan Posts: 42 Trader Rating: (0) Feedback Score: 0 reviews	Injector power wire, where is it?? I'm getting low voltage at the injector plugs, low enough for one cylinder to not fire at all. After checking everything else possible I'm pretty much 100% sure there's a bad connection where the main power line splits off to the 4 seperate injector wires. I just need to know where these connections are. I figure the main power wire splits off somewhere in the harness farily close to the injectors, but I wanted to make sure it's not some where else before I tear the harness apart.

01-01-2009, 06:25 PM	#6
Rayne Zilvia Addict Join Date: Feb 2005 Location: Earth Posts: 676 Trader Rating: (0) Rides Gallery: Rayne Feedback Score: 0 reviews	Got a copy of the FSM? __________________ Do need the Factory Service Manual? Click here.

01-01-2009, 07:07 PM	#8
projectRDM Post Whore! Join Date: Dec 2002 Location: Atlanta Age: 51 Posts: 13,812 Trader Rating: (12) Feedback Score: 12 reviews	Stupid question, but did you swap the injector? Try swapping plugs from another injector that you know is good, plug it in to the questionable one. __________________ FORMERLY R240NA Learn what's really going on and protect your assets now before they're gone forever: www.paypalsucks.com

01-01-2009, 01:17 PM	#2
reinvent BANNED Join Date: Dec 2008 Location: illinois Posts: 104 Trader Rating: (0) Feedback Score: 0 reviews	mind reader i must be.

01-01-2009, 01:23 PM	#3
invain Join Date: Jul 2008 Location: Michigan Posts: 42 Trader Rating: (0) Feedback Score: 0 reviews	I know how the ecu grounds the injectors. All I need to find is the connection for the 12 volt source. Where is this relay? Fuse box in the engine bay or down under the dash on the drivers side?

01-01-2009, 01:29 PM	#4
reinvent BANNED Join Date: Dec 2008 Location: illinois Posts: 104 Trader Rating: (0) Feedback Score: 0 reviews	cool. glad you know what you are doing.

01-01-2009, 04:03 PM	#5
invain Join Date: Jul 2008 Location: Michigan Posts: 42 Trader Rating: (0) Feedback Score: 0 reviews	Well, we fixed the voltage problem, there was a short in the power wire for that injector and the connection back in the harness was pretty shitty too. 12 volts at the injector plug now, but it's still not firing. We've checked continuity for the ground wire back to the ecu for that cylinder and it was fine. We've tried 2 different ecu's as well to rule that out. Now I'm back to thinking it's the CAS. However, I can't find any diagrams that show exactly which wires are for which cylinders. If anybody knows that'd be awsome.

01-01-2009, 06:57 PM	#7
invain Join Date: Jul 2008 Location: Michigan Posts: 42 Trader Rating: (0) Feedback Score: 0 reviews	Yeah just ran through the guide in the fsm and checked all the connections. No dice. At this point I have no clue wtf is going on unless the cas is bad. Can a malfunctioning cam position sensor cause only one cylinder to misfire? We checked all connections to the cas according to the fsm. We checked all connections to the injector. Fixed a small short in the power wire to injector 2 so it now shows the correct 12 volts. We've used two different ecu's with no change in cylinder 2.

01-02-2009, 09:28 AM	#9
invain Join Date: Jul 2008 Location: Michigan Posts: 42 Trader Rating: (0) Feedback Score: 0 reviews	Yep we've already tried swapping injectors.

02-16-2009, 07:05 AM	#10
89dc240 Zilvia Junkie Join Date: Nov 2006 Location: Just South of Philly Age: 41 Posts: 352 Trader Rating: (0) Feedback Score: 0 reviews	You figure this out?