ls1 coil pack wiring
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On The Tree
Joined: Oct 2009
Posts: 106
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From: Northern VA
ls1 coil pack wiring Hey, just put a cam in my 98 TA M6. It's backfiring to beat all and it only started doing it once it warmed up, i'm thinking i put the coil wires on backwards. Anyone can tell if the white marker on the harness always goes to the front? both sides have it (white piece of tape just before the last coil harness plug).
take pics.. there should only be one way the coils harness goes on because each coil harness plug is a different length that corresponds to the correct coil.. I don't know how you could have put them on wrong???
Wiring colors from the PCM. The coil harness (from the coil packs to the white plug in the center of the coil pack bracket) may only have solid colors.
1: purple
2: red/white
3: blue
4: dark green/white
5: dark green
6: light blue/white
7: red
8: purple/white
1: purple
2: red/white
3: blue
4: dark green/white
5: dark green
6: light blue/white
7: red
8: purple/white
Thread Starter
On The Tree
Joined: Oct 2009
Posts: 106
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From: Northern VA
awesome, thanks, got it, and yes you can put it on backwards, the ps was on backwards! the wires still reach fine. For anyone searching this the white label goes towards the front on the d.s. and the rear on the p.s. Apparently they were labeled 1/8, 7/2 etc. but mine all wore off, I was able to find one that was not completely worn and figure it out from that! of course that was after searching the colors thanks to the prev. post. Appreciate the help!
Thread Starter
On The Tree
Joined: Oct 2009
Posts: 106
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From: Northern VA
It seems to be pulling stronger throughout the band but my throttle response is crap, taking too long to climb through the rpms. I have stock tb and stock lid, gonna swap those and hope for a dif. Just did the ls6 swap too so I'm sure i'm not getting the full potential because of the lid and tb! going to try and port the tb tonight.
My new conversion (turbo built 5.3) was doing this(running on one side only). So freaking perplexing. It was backfiring and no matter what I did on the "Real Time Tuning" with my HPTuners, it still ran like crap. I didn't know immediately that it was only running on one side of the motor but I happened to be under the car routing a harness after having let it idle for several minutes. I absent-mindedly placed my hand on the drivers side header and then, remembering it had been running minutes ago, instinctively jerked my hand away. But then realized, the header was cool to the touch. I put my hand on the other header and promptly got burned. WTH? So I got out my 'noid light out and verified the injectors were firing. Pulled out the plugs, grounded them and then cranked. Great spark. Thanks for posting this. I realize it's old but it looks like it may be something I can validate. I'm not near the car(working on a contract in another state) but I'll check it out when I get home (Next week at this time).
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Dang. Can't believe I forgot to update this but that's what it was. My engine conversion came together over a year of collecting parts here, there, everywhere. Included in the piecemeal nature was loose coils from one guy and coil harnesses from another. I didn't know they could be 'upside down' and thus wired incorrectly. Flipped it over and, viola!, firing perfectly.
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On The Tree
Joined: Feb 2015
Posts: 145
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From: Brisbane, Australia
Dang. Can't believe I forgot to update this but that's what it was. My engine conversion came together over a year of collecting parts here, there, everywhere. Included in the piecemeal nature was loose coils from one guy and coil harnesses from another. I didn't know they could be 'upside down' and thus wired incorrectly. Flipped it over and, viola!, firing perfectly.
Also, I just realised this is probably what I have done as well! LOL
I did a 24x conversion of my SBC and had relocated my coil packs to the firewall, but kept burning spark leads, so I moved it back to the original LS1 location.
Had the exact same symptoms here, engine running like crap and LHS headers running cold.
The remembered I haven't bolted the coils in place yet, and suspect I've put them upside down with the firing order back to front.
Oh well, that was $250 spent on new coils i didn't need. You live and you learn.
Thanks for posting the solution, it seems to be a rare thing nowadays.
Registered User
Joined: Mar 2021
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Coil pack harnesses My coil pack harness has the white on both of them with number 3107. One of the have 1/8 on and the other has nothing or it rubbed off over time. Which side does the 1/8 goes on. Please help thank you
Teching In
Joined: Dec 2013
Posts: 18
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11 years later, thank you!!!!! been getting my *** whooped all day with a backfire. my harness and coil had green paint at one end, I ASSumed that was #1 but number 7 with the paint.
Helpful tip, right to left, RED RIGHT
regardless which side you put the coils on, RED RIGHT.
There is only ONE red wire in each harness. If it is original loom, you’ll have it sorted in about 6 seconds.
red is 7/2 green is 5/4 lt blue is 3/6 and purple is 1/8.
regardless which side you put the coils on, RED RIGHT.
There is only ONE red wire in each harness. If it is original loom, you’ll have it sorted in about 6 seconds.
red is 7/2 green is 5/4 lt blue is 3/6 and purple is 1/8.
