New Glow Plugs Installed; Starts Worse Than Ever

[cucvrus]

Rick,

In your experience is it actually necessary to replace a resistor(s), or just simply make sure wires/connections are in good shape?

I've been having an intermittent cold start issue on my '84 M1028 - sometimes hard to start in colder weather with extended cranking and/or cycling of the glow system - and so have replaced glow plug controller card, glow plug relay, and glow plugs (AC60G's), which helped a bunch, but thinking the resistors are the last point in the system to the intermittent cold start issue.

Brad

Brad could it be fuel related? And if you think it is the glow plugs I would recommend removing them all and bench testing them. I use Ac Delco 13 G glow plugs and replace glow plugs as they fail. Seldom do I just all out replace all 8 unless a customer or vehicle requires I do that. Good Luck. Report back.

 

[BradL84D30M1008]

Brad could it be fuel related? And if you think it is the glow plugs I would recommend removing them all and bench testing them. I use Ac Delco 13 G glow plugs and replace glow plugs as they fail. Seldom do I just all out replace all 8 unless a customer or vehicle requires I do that. Good Luck. Report back.

Thanks Rick,

Don't think it's fuel related....I bench tested all 8 glow plugs (resistance via my multi-tester) prior to replacing and found 3 of 8 to have higher resistance (>1.5 ohms) than the other 5 (between 0.5 - 0.9 ohms)....and no big deal to replace all 8.....and replacing all 8 glow plugs definitely reduced the glow plugs cycling on/off rather violently when starting in cold weather.....dash volt meter would ping pong back and forth.

Now I'm just trying to address why the truck starts perfectly fine sometimes in cold weather, and sometimes requires 2 cycles of the glow plugs to start.....it's like the glow plug control card/light definitely indicates the glow plugs are warming longer in a cold start scenario, but the glow plugs are not actually getting hot enough to start so the truck requires extended cranking to start...and this on an intermittent basis, only when cold, otherwise the truck always starts instantly.

Brad

 

[cucvrus]

https://www.steelsoldiers.com/threads/meet-mr-rusty.140975/page-7

Check out my Meet Mr. Rusty thread. I encountered this on a few CUCV's where the glow plug wires were burnt and bad upstream from the glow plug connections. I made a few new glow plug harnesses and just installed them in their own loom with a separate harness. At 36 years old things are getting crispy inside that old harness. A lot of resistance has flown thru them old wires over the years. Good Luck. Report Back.