411 Swap 96-02 injector #1 not firing

[HellKnightHicks]

There are several reported incidents of people with recent versions of EFI live flashing OS and Tune and losing cylinder #1 after chaning PCM's

I myself have seen this issue and am working on one i have taken a known working PCM and after flashing still didnt have Cylinder #1.

At this point I have to thing its either something thats changed in an update or something wrong in the flashing of the Operating system.

Ill link this for others to post up too.

Wiring has been tripple checked.
19003

lots of details here.
http://forum.gmtruckcentral.com/showthread.php/1707-411-MOD-DROPPING-1-CYLINDER

Thanks for your time.

[spastik monkey]

thanks for the info. hope I don't run into this

[5.7ute]

You pulled a pcm out of a good running truck. Flashed an OS into it and put it in the truck with the dead hole and it's still there. Tells me you have a wiring issue not a tune issue.
Have you tried running a different OS?

[HellKnightHicks]

Any recent swap on my home forum seems to have resulted in this issue.

I did the swap on another truck some time ago and had no issues what so ever...

Even used the PCM from it on my successful swap and the issue was the same.

Wiring is not the issue I've checked it several times and we are currently looking at other wiring files to see if there are any issue there.

No have not tried a different OS. Would you be able to help me with that?

[5.7ute]

I am not up to date with what OS can be used on what, Sorry.
Have you noid lighted the coil and injector circuits to see what side is faulting? (or both)

[joecar]

Also check the terminals in the coil and injector plugs... you may have to remove each one and inspect it, verify that it makes contact with its mating terminal pin.

[joecar]

Can you try this experiments:
- take PCM from truck with dead hole and run it in known good truck (without reflashing).

[spastik monkey]

i'm dealing with a misfire on mine. Not sure i have a solid base tune though.

[Chaz]

You ever figure it out??? have the same issue on my 98 with a marine intake and manual tranny with a 411 tuned be pcm for less. I can manually fire all the injectors just fine through a injector balance test through a snap on modis diagnostic but injector one wont fire while its running. Weird thing is when i have it on a noid light injector one will get a couple pulses when i first start it but then nothing.

[joecar]

Check engine ground connections (in particular cylinder head ground).

[Chaz]

I actually had to fix that ground because it gave me issues when i swapped the intake and 411 in. Grounded good now but ive even tried directly grounding all the ground wires from the pcm to the battery with a test wire to eliminate any possibility of issues in wiring harness... no difference