New HMMWV

Hey guys, so this is my first post. Recently come into acquisition of a beautiful 1988 m998. One **** of a monster, started and ran just fine. Brought it up to shape a little bit here and there with restoration, and I can say that Im the proud owner of a beastly american machine. However, as of recent, shes been acting up. More specifically, the ignition system. I read thoroughly on your forum before I actually decided to post, and let me just say Im glad to have a resource like this available.

Anywho, more to the point. The glow plugs controlled burnt up. It was staying on at all times, and the glow plugs swelled up inside the engine, I couldnt get them out. Pulled off the heads, send em to the machine shop and got them redone. Pulled out all the swollen ugly looking glow plugs which were cracking and warping. After getting the heads back, I threw them on and got all new gaskets and seals, excited to get this monster running again. Got it all reassembled, popped in some brand new wellman "swellproof" 24v plugs, hooked it all up to a brand new nartron smart start unit with matching temp controller, and lo-and-behold, theyre swelling up again. I hooked up a direct line to a glow plug outside of the engine just to see what would happen, and it literally blew up. The light for the glow plugs is flashing. I checked all the grounds, connectors, fusible links, and anything else feasibly that I could think of. Im stumped. Anyone got any ideas?

For reference, the part number for the plugs on amazon is B01E1XTL56.

If there is a "introduce yourself first" policy, I apologize for I have not found one glancing through the rules. In any case, thanks in advance and god bless.

You hooked a direct line to s glow plug from what? Was it to the plug or to the wire that was on the plug?

Hooked it up through the glow plug module connector, grounded it outside the engine, and turned the key. It hit extreme temperature almost instantly, and it was the whole tip glowing/swelling up. It appears as if it does not cycle, what makes the glow plug cycle?

I had a similar problem with my 998. Put all new plugs in and swelled them all on the first start. After buying the swollen plug extractor from Kascar and new smart start box with tsu, the machine starts every time. I know the box is a little salty but it's worth every penny.

Yea i suspect this smart box is defective.

I have had several trucks where the glow plugs were simplified system without any controllers just a big button. Hold short for summer, long for winter. Seemed like a fine way to go when compared to the seemingly fragile controllers. Has anyone done this to these trucks? I'm pretty sure I could keep the plugs from swelling but maybe the cycling between plugs is more to reduce amps on the system?