Single Purple Wire in engine bay 1989 K1500

[Scooterwrench]

On the no spark issue check the IC module and connector. If your tranny shop let the engine fall back when they took the tranny out it could have cracked the IC module or knocked the wires loose or cut one of the wires.
Don't ask me how I know this!!!

 

[johnsonmtz]

On the no spark issue check the IC module and connector. If your tranny shop let the engine fall back when they took the tranny out it could have cracked the IC module or knocked the wires loose or cut one of the wires.
Don't ask me how I know this!!!

That's the route I'm thinking is the ICM was possibly damaged. I'd like to test it to confirm before just replacing, but I also know these are famous for taking a dive, so it could also have just been time for it to flake out. I installed a completely new distributor 3 years ago when I installed the reman engine, but it's possible the ICM crapped out.

 

[L31MaxExpress]

That's for a second O2 sensor. 4.3's ran two sensores and GM made up the wiring harness to service all V configured engines of that era. My 91 has it too.

From memory the 4.3L ran dual knock sensors, not dual 02 sensors.

 

[Scooterwrench]

From memory the 4.3L ran dual knock sensors, not dual 02 sensors.

Yup! My bad! What was the reason for the second O2 wire? Different configurations had the sensor in the right manifold?

 

[L31MaxExpress]

Yup! My bad! What was the reason for the second O2 wire? Different configurations had the sensor in the right manifold?

Never seen one with an 02 on the passenger side except ones in the Y-pipe. Good question to be honest.

 

[johnsonmtz]

On the no spark issue check the IC module and connector. If your tranny shop let the engine fall back when they took the tranny out it could have cracked the IC module or knocked the wires loose or cut one of the wires.
Don't ask me how I know this!!!

ICM was the culprit. I installed a new one and the engine fired immediately. Prior to that I had zero spark. I didn’t see any evidence of pinched wires or impact against the firewall so maybe it’s just coincidence.

I did recently have an issue of the battery frequently draining. That was solved a couple weeks ago, but I’m wondering if those low voltage situations maybe shortened the life of the ICM.

 

[justme]

That looks like a timing connector on my 92

 

[justme]

Circuit 430 is a purp/white for timing bypass (unplug to set) connector..... has anyone else used "charm.li" for service manuals??

 

[PlayingWithTBI]

Circuit 430 is a purp/white for timing bypass (unplug to set) connector..... has anyone else used "charm.li" for service manuals??

Not around here, most of us use the Factory Service Manuals here...

88-98 Service Manuals

Over the years I have collected a bunch of GM service literature. Links to PDF Scans of service and STG manuals and a links to the Parts manuals. You'll need the FREE Adobe Acrobat reader to open these files. Get it directly from Adobe here {http://get.adobe.com/reader/} If you're not...

www.gmt400.com

 

[Scooterwrench]

I know Haynes manuals make good kindlin.