captainhooky

Hello all,
I recently puchased a 1995 Chevy P-chassis Motorhome with a 7.4 TBI engine. I was trying to do some basic tune up and data collection for my own peace of mind.
My intent was to change plugs and plug wires one at a time and test compression while I had each plug out.
I removed the coil wire completely. Screwed in compression tester and spun engine. Bad idea! injectors spraying and coil sparking to ground. Re-installed coil wire to coil only and moved where it couldn't ground. Disconnected injector plugs. Continued around one at a time until finished. comression ranged from 140 to 150 cold. Found 2 bad plug wires and 2 fould plugs and was exited to feel the difference in the engine. Re-connected coil wire and injector plugs. Now injectors won't fire. Any ides?
Thanks for any help.

captainhooky

Did I post in the wrong place?

captainhooky

It was a blown ECM fuse which was harder to find that it was to replace. I finally had to call Fleetwood and the chassis fuse panel was under the instrument cluster which lifts up like a suitcase lid. The engine now runs great with a noticable increase in power. Next step is a MSD blaster coil, cap and rotor.