Originally Posted by 73 Mike
First the disclaimer. Iím 750 miles away from my extensive notes and service manual on the E4ME. Youíll have to trust to my memory and that ainít good.
If itís clicking, that means your solenoid is working. Very good start. Likely means your computer is still alive too. Is the check engine light on? Does it light up when you start?
MCS only 'clicks' if I force ground the 'ground wire' with key-on (I believe) it's Gray or Tan in color...difficult to tell.
When I turn-on the key CEL comes on then goes off when engine is running...HOWEVER...MCS is NOT clicking anymore.
When I disconnect the MCS Plug and apply a separate HOT and GROUND wire directly to the MCS it will click every time I insert/remove the temp Ground Wire.
testing with a 12v Test-Light, MCS plugged in, key on and I stab each of the two wires from MCS Plug BOTH Pink and Gray light Test Light = both HOT.
*with MCS unplugged and I test both inner sockets on the Plug...the faded Pinkish wire lights Test-Light-HOT and the Tan/gray wire is dead-grounded.
*where I'm at now...I had the battery unhooked for a few days (father in nursing home) and I had hopes once I reconnected the Battery the MCS would start clicking again when key is on...NOPE!
*I started the engine and unplugged the MCS...the engine imeditaly idled better but the CEL came on. Plug the MCS back in, engine drops RPM and idles poorly but...CEL goes out.
*I checked for codes by jumping the two far left sockets in the plug under the Ashtray.
*turn key to 'on'...MCS starts clicking and CEL light flashes **-***, **-***, **-*** over and over for a dozen plus times, no other sequence of CEL light.
*I'm getting PISSED...I remove drivers seat, yank the battery, yank the Computer (nothing easy on these cars to work on)
*** my next thing is to somehow locate the two DISCOLORED wires at the MCS and find out where those same non-discolored wires enter the two large plugs that go into the computer, and check for continuity to make sure the run from MCS to ECM Plug is good...AND...if I get LUCKY enough to locate those two wires I'll attempt to run a 12v hot and GROUND to those wires to see if the MCS clicks. That test should prove the wires between the MCS to ECM are good and I would then assume the ECM is bad???
***maybe someone can confirm: are the two wires at the MCS Pink w/a black stripe (hot) and the other wire Gray w/a black stripe ground??? (I'm not 100% sure of the Gray ground wire)
The wires going into the ECM plugs have good color, the two going into one of the ECM Plugs are faded bad but one looks somewhat Pink and the other Tan/Gray.
*** so that's where I'm at...I don't have much more hair to pull out, and I suck at wires/electronic diagnosing. But I can do everything else!
I need this Car up and running because if my Diesel Truck craps the bed I have no way to get to my Fathers nursing Home and my daily visits are paramount, he's not well.
EDIT...I remember sometime in 1983 I took the car to my local Chevrolet dealer for an issue and the ECM had an extended 5-year warranty. Sure enough the ECM I just pulled out was a GM Remanufactured, I purchased the car new in 81.