Looking for 6.2 diesel nerds

[93M6Formula]

Originally Posted by 66gmcguy

Hello all, I made this account about 6 years ago but haven't really been on it until recently to post some square body parts for sale, and to get some technical help.

I just picked up a 1982 GMC K2500 with a 6.2 diesel engine. This is my first diesel engine, so I am still learning about them. I drove one hour with freeway, mountain, and city driving all on the way home and it seemed to be running great and make decent power. I went to go start it the evening after I got it home and lo and behold, it wouldn't even fire. I eventually got it fired the day after drove it around again (to introduce the dog to the new truck, because car rides in the back of trucks are his favorite thing, even more than eating.) I shut it off, and it started back up 2ish hours later, but the next day, I couldn't get it cranked, even after letting the batteries sit on the charger for a couple hours, and with the block heater plugged in (which I am unsure if it even works.) I decided to test the glow plugs with a test light, and sure enough, none of them worked, so I am going to replace them tomorrow. Is there anything else that might be causing this non-start issue that I should look for? When I crank it, smoke comes out of the exhaust, but it never fires.

Also, I should mention, one of the previous owners installed a manual control for the glow plugs. Will this cause any issues? Also, what should I look out for as far as problematic components with these engines? I bought this truck with the intention of doing a gas engine swap, but I decided I liked the diesel too much to replace it just yet.

Sounds like possibly a couple of things. The 82-84 glowplug system is junk at best which is why it is bypassed with a switch. The only problem is, if it had the older style plugs, they do not hold hold up with extended glow times they might see when on a switch. The newer Ac Delco 60G or Bosch Duraterm are self limiting and won't swell so they are okay with longer glow time. So I would replace them either way but be prepared that some may be swelled and will be a pain to remove. Double check the wiring they did for the glowplug system, it may have some issues.

Since you said it's smoking while cranking, that means it's getting fuel so it does sound like a glowplug problem more than likely. I would however make sure the fuel system is 100% tight from tanks to engine, air intrusion is the biggest thing that can cause all sorts of issues with starting and running. Also these need to crank fast to start well.