Tach or Coil pack, I have to choose?

tenchu · 06-02-2010, 03:32 PM

Okay so I stopped getting spark in my #2 cyl out of nowhere. After checking all fuses, replacing the coil pack, plug, etc, I ended up trying to find a break in the wiring, since it was getting 12v power, and had a good ground, it just wasn't getting signal from the ecu to spark. When I traced the signal wire from #2 cyl it appeared to run into a green/blue wire. I followed that wire all the way to the firewall where it was getting continuity, then i lost it behind the dash, re-appearing down by the ecu, where it no longer got continuity, so I cut the wire at the ecu, and where it entered the firewall, and ran a new wire joining those two, which fixed the spark problem. But then the tach stopped working. When I disconnected the new wire, and put it back to the way it was originally, the tach started working, but the spark in #2 stopped. So it almost like the coil is somehow ran into the same wiring as the tach, or i some how got it working with the coil getting signal from the wire thats supposed to go to the tach? Because theres also the same color blue/green wire that plugs into the cluster.

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Legacy777 · 06-02-2010, 03:46 PM

More than likely the tach is tied into that wire to the coil.

If you tie the wire going to the tach to the new wire you put in, everything will probably be back to normal.

tenchu · 06-02-2010, 03:49 PM

If I do that, I have neither tach nor coil

Legacy777 · 06-02-2010, 05:38 PM

Ok....that's weird.....hmmm

Any chance you have a wiring diagram?

69subaru360 · 06-02-2010, 08:59 PM

Stock tach in the dash or aftermarket? The stock tach has a seperate wire off the ecu.

tenchu · 06-02-2010, 10:04 PM

Legacy, I have a wiring diagram I got from SubarDave but I can't seem to figure it out.

69Subaru, Stock tach

theonlygreat · 06-02-2010, 10:42 PM

The following information is based on you having an EJ20G, I also assume you have converted to 02+ Coil packs because you make no mention of the ignitor. If that is true the first place I'd look is where the ignitor removal wiring was done.

Are you sure it's #2? The blue/green wire in the engine bay should be to #4 and that wire should cease to exist at the ignitor or splice into the black/red if its removed. The blue/green at the computer is only to the tach. The correct wire for #4 at the ECU is black/red, pin 7. The correct wire for #2 at the ECU is red, pin 8. The ignition outputs are all in the 26pin connector.

tenchu · 06-02-2010, 11:53 PM

Quote:

Originally Posted by theonlygreat

The following information is based on you having an EJ20G, I also assume you have converted to 02+ Coil packs because you make no mention of the ignitor. If that is true the first place I'd look is where the ignitor removal wiring was done.

Are you sure it's #2? The blue/green wire in the engine bay should be to #4 and that wire should cease to exist at the ignitor or splice into the black/red if its removed. The blue/green at the computer is only to the tach. The correct wire for #4 at the ECU is black/red, pin 7. The correct wire for #2 at the ECU is red, pin 8. The ignition outputs are all in the 26pin connector.

Yes its an EJ20G, and yes 02+ coil packs. The igniter was removed with running 12v constant power (yellow wires in my case) to the coil packs, and the ground is directly to the bolt that holds the coil pack into the head. I THINK that its #2, from what understand is, looking at the engine bayrec, first plug on the left is #1, behind that is #3, front right is #2 and rear right is #4. If i'm correct, then it is #2. The front, right side coil (looking at the engine from the front) is the one that is dead, unless for some reason I have the plugs backwards somewhere (white front, black rear). Does anyone have a pinout diagram so I can find and verify those pins (7&8)? I greatly appreciate your help, theonlygreat.

tenchu · 06-03-2010, 12:02 AM

upon further diagnostic, i think i may have something reversed. when i was tracing wires, i ended finding out that the solid red wire at the ecu was cyl #4, so maybe i have a plug reversed somewhere in the engine bay, and #4 is actually #2, but the plugs are reversed at the engine?

theonlygreat · 06-03-2010, 12:30 AM

ECU Pinouts

That's the link you need to figure out the wires at the ECU. I would really look at the splices where the ignitor was removed, should be near the intake box/strut tower. I could easily believe the plugs being reversed, but your car would've run funny unless they were wired reverse as well.

tenchu · 06-03-2010, 12:40 AM

Well sir, you just fixed my car

Thank you very much for the assistance. I reversed the plugs in the engine bay so that white is in the front, and black is in the rear, but blk/red goes to 4 and red goes to 2. Now my tach, and all 4 plugs work!! Now I just have to replace my dead injector, and figure out why my cluster fuse keeps popping! Thank you again!!!!

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06-02-2010, 03:32 PM	#1
tenchu Scooby Specialist Member#: 64147 Join Date: Jun 2004 Chapter/Region: MWSOC Location: Milwaukee, WI Vehicle: 1993 STi RA V LTD Green	Tach or Coil pack, I have to choose? Okay so I stopped getting spark in my #2 cyl out of nowhere. After checking all fuses, replacing the coil pack, plug, etc, I ended up trying to find a break in the wiring, since it was getting 12v power, and had a good ground, it just wasn't getting signal from the ecu to spark. When I traced the signal wire from #2 cyl it appeared to run into a green/blue wire. I followed that wire all the way to the firewall where it was getting continuity, then i lost it behind the dash, re-appearing down by the ecu, where it no longer got continuity, so I cut the wire at the ecu, and where it entered the firewall, and ran a new wire joining those two, which fixed the spark problem. But then the tach stopped working. When I disconnected the new wire, and put it back to the way it was originally, the tach started working, but the spark in #2 stopped. So it almost like the coil is somehow ran into the same wiring as the tach, or i some how got it working with the coil getting signal from the wire thats supposed to go to the tach? Because theres also the same color blue/green wire that plugs into the cluster. * Registered users of the site do not see these ads.

06-02-2010, 03:46 PM	#2
Legacy777 Scooby Guru Member#: 4800 Join Date: Mar 2001 Chapter/Region: TXIC Location: Houston, Tx Vehicle: 1990 Legacy & 97 OBS AWD 5MT EJ22T AWIC Swap	More than likely the tach is tied into that wire to the coil. If you tie the wire going to the tach to the new wire you put in, everything will probably be back to normal.

06-02-2010, 03:49 PM	#3
tenchu Scooby Specialist Member#: 64147 Join Date: Jun 2004 Chapter/Region: MWSOC Location: Milwaukee, WI Vehicle: 1993 STi RA V LTD Green	If I do that, I have neither tach nor coil

06-02-2010, 05:38 PM	#4
Legacy777 Scooby Guru Member#: 4800 Join Date: Mar 2001 Chapter/Region: TXIC Location: Houston, Tx Vehicle: 1990 Legacy & 97 OBS AWD 5MT EJ22T AWIC Swap	Ok....that's weird.....hmmm Any chance you have a wiring diagram?

06-02-2010, 08:59 PM	#5
69subaru360 Scooby Guru Member#: 159682 Join Date: Sep 2007 Chapter/Region: NESIC Location: Belfast Maine Vehicle: 1995 WRX	Stock tach in the dash or aftermarket? The stock tach has a seperate wire off the ecu.

06-02-2010, 10:04 PM	#6
tenchu Scooby Specialist Member#: 64147 Join Date: Jun 2004 Chapter/Region: MWSOC Location: Milwaukee, WI Vehicle: 1993 STi RA V LTD Green	Legacy, I have a wiring diagram I got from SubarDave but I can't seem to figure it out. 69Subaru, Stock tach

06-02-2010, 10:42 PM	#7
theonlygreat Scooby Newbie Member#: 65916 Join Date: Jul 2004 Location: Seattle, WA Vehicle: 1996 Impreza WRX	The following information is based on you having an EJ20G, I also assume you have converted to 02+ Coil packs because you make no mention of the ignitor. If that is true the first place I'd look is where the ignitor removal wiring was done. Are you sure it's #2? The blue/green wire in the engine bay should be to #4 and that wire should cease to exist at the ignitor or splice into the black/red if its removed. The blue/green at the computer is only to the tach. The correct wire for #4 at the ECU is black/red, pin 7. The correct wire for #2 at the ECU is red, pin 8. The ignition outputs are all in the 26pin connector.

06-03-2010, 12:02 AM	#9
tenchu Scooby Specialist Member#: 64147 Join Date: Jun 2004 Chapter/Region: MWSOC Location: Milwaukee, WI Vehicle: 1993 STi RA V LTD Green	upon further diagnostic, i think i may have something reversed. when i was tracing wires, i ended finding out that the solid red wire at the ecu was cyl #4, so maybe i have a plug reversed somewhere in the engine bay, and #4 is actually #2, but the plugs are reversed at the engine?

06-03-2010, 12:30 AM	#10
theonlygreat Scooby Newbie Member#: 65916 Join Date: Jul 2004 Location: Seattle, WA Vehicle: 1996 Impreza WRX	ECU Pinouts That's the link you need to figure out the wires at the ECU. I would really look at the splices where the ignitor was removed, should be near the intake box/strut tower. I could easily believe the plugs being reversed, but your car would've run funny unless they were wired reverse as well.

06-03-2010, 12:40 AM	#11
tenchu Scooby Specialist Member#: 64147 Join Date: Jun 2004 Chapter/Region: MWSOC Location: Milwaukee, WI Vehicle: 1993 STi RA V LTD Green	Well sir, you just fixed my car Thank you very much for the assistance. I reversed the plugs in the engine bay so that white is in the front, and black is in the rear, but blk/red goes to 4 and red goes to 2. Now my tach, and all 4 plugs work!! Now I just have to replace my dead injector, and figure out why my cluster fuse keeps popping! Thank you again!!!!