LS3/480 GMPP harness - no heat on even bank..
 

Hey guys/ladies.
First post here. Having some issues with an LS3/480 conversion. Hoping someone here might have had a similar issue.

A short background on the conversion. The engine is a new GM LS3/480. and the matching GMPP controller kit (harness, ecm, etc). I have a pretty good control wiring background so I felt confident in tailoring the harness to fit the application a bit better than it came out of the box.

First attempt to fire the engine: It lit off immediately, YAY! or so I thought. It was running terribly rough. Shut it down and performed the visual look over for something obvious. That is when I noticed that the header on the even bank was ice cold, odd bank was hot.

Since I modified the harness I suspected that I had made an error at some point in my wiring. To date I have run the pin outs 3 separate times. All checks out good. Tried re-firing several times with the same results.

I have checked for ignition power to the coils and injectors, good there too.
Put a Noid light on as well, shows the injector firing.

I managed to locate another harness and ECM. I overlayed the unmodified harness to confirm or deny that I had made a wiring error. Fired it up with the new harness...same result. Swapped the ECM...same result.

Anyone know of a scenario that would cause this?

Thanks and really enjoy this site! Very inspiring to say the least.

Terry

Interesting. You have confirmed with a noid light and voltage tests that the injectors are firing. And you have confirmed that your coils are getting power also. Have you pulled number 2 plug and checked for spark visually?
Check your grounds. All of them. Make sure the bolts your using for your ground connectors aren't bottoming out in the holes, before there making contact at the head of the fastener. This is pretty common.
Is it possible to verify fuel at all injectors? Possibly an internal blockage in the rails, to the last side injectors?

Problem Solved!
 

Found the trouble.
I had the coil pack harness reversed on the even bank. Flipped it around and everything works as it should.

I know we read a ton of threads out there with people having the same issue. Hopefully this will help someone down the line!

TerryD

Cool Terry, but I think we need a build thread:thumbsup: looked at your Blog seems like a cool project.:hello: