I remember it staying on for 10 seconds or so, but recently on only goes on for half a sec, then starts clicking, while engine still cold, in the morning.

What do I gotta do to have it stay on longer? It's hard to start the truck in the morning .

 

Check your glow plugs. As I recall (but not 100% sure) . . the glow plug controller works off of total glow-plug resistance. If a few burn out -it only comes on for second or two. That's the way my Chevy and Isuzu work. I never had to fix any of the glow plugs on my Ford 7.3 since it has the German plugs that Ford sticks in a Motorcraft box now (Made by Beru). The Beru plugs are dual-coil and supposedly burn-out proof, or at least close.

 

<p>this is on your 86?</p><p>as said above, check the glow plugs. if they all test good, then the controller may be bad.</p>

 

My 90 did the same thing. Swapped glow plugs and all was good again

 

My 86 van stayed on quite a long time but still wouldn't start. I changed the controller and it works fine now. I use to have to plug it in to start.

 

Try a GP resistance test with an ohm meter first, even one or two bad GP's will give you a quick WTS light. Directions for test are in the sticky at the top of the page.

 

x2 for the sticky!!

 

Definitely a dead plug or two, bad GP controller, or both. Mine did that, I rigged a push button as a bandaid until I could get at the plugs, later found AC Delco glow plugs in the two rear cylinders that were both shot. But, even after a fresh set of Beru's, it still didn't work right when I hooked the GP controller back up so I just kept the push button.

 

The AC Delco plugs are self-limiting Beru plugs like Ford uses - unless they are old versions. AC Delco as used in GM 6.2 and 6.5 diesels switched to the AC60G Berus not long after Ford switched to Berus.

 

Yeah but the AC Delco plus are also known to be junk, it's well documented.

 

The AC Delco plugs that came OEM in Chevy and Isuzu diesels ARE junk. But somewhere along the way - AC Delco wised up and started buying Beru plugs and putting them in Delco boxes - just as Ford does with Motorcraft boxes. The Delco AC60Gs are made by Beru, are self-limiting dual-coil, just like the Berus Ford now uses. Many Fords in the 80s also had poor quality single-coil plugs OEM before the switch was made to Beru. The Delco AC9G or AC11G plugs are crap, but the Delco AC60Gs (for 6.2 and 6.5 diesels) are Berus and just as good as what Ford is using across the counter.

 

I guess I should of qualified my comment. I'm talking about the Delco glow plugs sold for 6.2 and 6.5 diesels. I have no idea what was stuck in your engine. If it was something like an 8G, then yeah - crap.

 

Mine had parts store AC Delco replacements, which are known to have the tips swell and get stuck in the head (fortunately mine were not like that)