[SOLVED] No Spark, Cylinder 1 and 4

GCPhotographers

Greenie N00B Member
Months work on this problem but not everyday.

Issue: No power to 1 and 4
What I did to troubleshoot:
  • swapped spark plugs
  • swapped ignition coils
  • ignition coil harness rebuilt
  • new MAF
  • new O2
  • main harness swapped
  • got injectors cleaned and new CS/Overspeed seals
  • compression tested
What I noticed before this happen:
  • It would drive good then suddenly at times especially in traffic, car will sound like a subbie (you can hear cylinders died). I would have to pull to side of the road.
  • Another time I was on the highway and the suddenly, I would loose power and I would be going and my car was at full throttle. Pulled over and then the car would sound like a subbie and after some time, back to normal
  • Another time I was leaving a packing lot and everything was good then went over a bump....a few minutes after, subbie.
What do I notice in troubleshoot:
  • fuel smell in tail pipe
  • P0172
  • coil pack test for spark even when swapped... 1 and 4 .. no power
  • everything at the top
I was planning to look at every ground wire but after changing the main harness, building another, and checking another, I am curious what else is needed. Any help would be appreciated.
 
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coil pack test for spark even when swapped... 1 and 4 .. no power
Coilpacks on this car are batch fired; 1-4, 2-3 are linked directly. Hopefully it's something stupid simple like a bad ground (there's a small green wire on the HPFP bracket that you might want to look at) but might be the ECU or a pin in a connector or something.
 
Also what happens if you unplug the MAF while you are having the problem

When I did it I believe last month, there was a struggle if I recall. I have a new MAF. Happy Memorial Day Brother. Long time.

Coilpacks on this car are batch fired; 1-4, 2-3 are linked directly. Hopefully it's something stupid simple like a bad ground (there's a small green wire on the HPFP bracket that you might want to look at) but might be the ECU or a pin in a connector or something.

Remind me of what this green wire looks like. It don't recall this. With all the harnesses swap, the ECU can be the issue. Spoke to Jordan of Overspeed and with everything I shared, he said ECU. I just want to drive my car and feel fast again...lol
 
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Kind of hard to see but should be under this bolt. Should look alot like the one on the passenger engine mount but with a smaller wire.
qE6Typd - Imgur.jpg
 
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main harness swapped and coilpack harness custom rebuilt recently.

Check all of the connectors to make sure they are fully plugged in, the connectors aren't broken and that none of the wires have been pushed out of the connectors. Try wiggling the wires while the car is running to try and replicate the issue
 
Do we have a diagram of the locations of the ground wires to verify as well as the ground or power diagram for the 1 and 4 plug connectors?
 
I wonder if it's something to do with the coilpack harness.
2nd time rebuilt by Kyle Rotter. See photo. He had a few post on FB about builds. I took him on as he had a few combos to make the bay cleaning especially that Eric Yarbough retired.
Screenshot_20240603_114023_Facebook.jpg
 
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