New Setup issues

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Feb 8, 2021 | 08:38 PM

Vette-byrd

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From: NC

New Setup issues

Previously had a 5.3 with term x which ran great-now have a 6,0 with 862 heads and ms3 cam ( same fuel system, same injectors and everything as before. Now I’m only getting a weak spark at cylinder 3 and 2.
Ive already triple checked the injector and coil wires as well as the coil grounds. Engine starts right up and runs rough before eventually stalling.
#7 led for cam is red-I’ve already tried another cam sensor with no change.
any ideas?
All I can think of is to try coils next but it sounds like a wiring issue somewhere.

Feb 8, 2021 | 10:03 PM

AgFormula02

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From: Battle Ground, WA

Check your grounds for starters.

Feb 8, 2021 | 11:01 PM

Vette-byrd

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Quote:

Originally Posted by AgFormula02

Check your grounds for starters.

Done.

Feb 10, 2021 | 08:30 AM

minytrker

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From: Brenham

Try running it in batch fire and see if it goes away. If it runs normal in batch then you have cam sensor issues.

Feb 11, 2021 | 01:41 PM

tblentrprz

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Verify power to problem coils. Compare to good coil. Look at coil trigger signal. You can use a meter however a scope is best to do this. Again, compare to good coil.

Feb 11, 2021 | 02:30 PM

Vette-byrd

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Quote:

Originally Posted by tblentrprz

Verify power to problem coils. Compare to good coil. Look at coil trigger signal. You can use a meter however a scope is best to do this. Again, compare to good coil.

just checked and I’m getting power to coils and injectors are getting signal(checked via noid light).
I swapped coils from a good car and I’m getting spark now but it’s red which I’m assuming means it’s weak.
also still have the red led for cam.
I also checked the coil grounds for the millionth time.

Feb 12, 2021 | 03:24 AM

Fang

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I've seen a YT video of someone with similar issues, turned out to be a terminal pushed back out of the coil harness inline connector and making poor/intermittent spark on one cylinder.

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Feb 14, 2021 | 02:56 PM

Vette-byrd

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From: NC

Still having issues-engine starts right up but getting a red led for cam.
Lq4 sbe.
Tried 2 good cam sensors. Cam wiring is getting 12v+.
Each coil grounded to head. Harness ground at frame. Red harness wire to junction box-box and battery have 13v+.
Red/white wire to factory fuse box and has 12v.