Chevrolet Repair: 1997 intermittent electrical shutoff, intermittent loss, load switch

Question
Hello Van,
I have a 97 chevy g2500 cargo van w/4.3
Recently while running, my van will try to cut off. Sometimes it just sputters a few times, other times it dies completely.
Mechanic changed key tumbler and electronic switch. They performed system test, said fuel pressure was fine as I suspected fuel pump was cutting on and off.
After repair, drove for awhile no problem. Then switched lights on and problem returned. Drove some more(highway) fine. Noticed that sometimes when applying electrical load( air, lights, turn signals,etc.) the condition could occur, but very sporadically. Usually van will just sputter like it's turning on & off.
I appreciate any ideas you might have.

Regards,
Greg


Answer
Hi Greg,
That sounds like a loose connection, and most likely a ground.
Make sure the ground wire from the engine to the firewall is in good shape. May be on a manifold bolt, or the thermostat housing bolt.

I would personally connect a fuel pressure tester, and go for a ride, just to make sure the pressure maintained, even during the problem.
But yours sure sounds like intermittent loss of a complete circuit, especially with the load switch.

Van