Damage to ECM while welding.

[Steve Jordan]

Have a 84 C4 with rust on rt side frame rail. Extensive welding was done and frame was repaired.
i went to start and And the engine seemed to be at wide open.
During the welding repair I did not take out the computer.
Fearing I need to replace ECM.
Is there something I am overlooking?

 

[compyelc4]

Have a 84 C4 with rust on rt side frame rail. Extensive welding was done and frame was repaired.
i went to start and And the engine seemed to be at wide open.
During the welding repair I did not take out the computer.
Fearing I need to replace ECM.
Is there something I am overlooking?

What type of welding? Did you disconnect the battery?

 

[Steve Jordan]

Battery was disconnected, mig welding

 

[compyelc4]

Battery was disconnected, mig welding

Steve, I sent a copy of your question to a good friend of mine who is a professional welder. Here is his reply:

Unfortunately when welding on vehicles (frames etc.) it is critical where you set up your ground back to weld machine. As you know computers are very sensitive to arc. I have welded on many vehicle frames and ALWAYS unplug computer and put ground clamp as close to work as possible. I have never fried one. Excited electrons ALWAYS find the shortest path to ground, even if that is directly through computer.

 

[Steve Jordan]

What type of welding? Did you disconnect the battery?

Ted was mig welding, yes battery was disconnected

 

[Steve Jordan]

Ted thank you for asking your friend about my issue.
My ground was right near or on the piece I was welding.
Hindsight wish I did unplug it. I know better.

 

[compyelc4]

Well good luck Steve. I suppose your getting codes all over the place?