Ok guys, I am back. Got busy and let the new girl sit only to find that some previous owner had drilled a few holes in the roof that I hadn't seen previously. He was better at drilling than patching and it leaked water in to the truck for about 3 months (I live in Western Washington so thats a ton) When I went out to check on her the ENTIRE interior was covered in mold so there was that to clean up. Oh well, I guess I will be putting a few bucks into the interior sooner than expected. BUT first I need to get her starting and running reliable.

I did the battery cable upgrade and new batteries before I parked her (thanks Custom Battery Cables! Great Kit) So this week I got it in the garage to figure out why she won't start. All 8 glow plugs appeared bad based on the numbers when i tested them so I replaced them all. When I went to start it the glow plug light stayed on for couple of seconds which worried me, but she started. Seemed like it should have been on longer but 'shrug' it started! Later that night I went out to start it and the light stayed steady for 8-10 seconds and she kicked right off! Yeah buddy. This morning I go out to get her rolling (my buddy is welding up the roof holes today) and the plug light goes on for maybe 2 seconds. It seems to cycle and I can hear the relay clicking as it does so. I try to start it but it doesn't' want to pop. So I let it cycle a couple more times and try again and she protests but starts. After she starts, the glow plug light comes on again and cycles off and on for a bit and then stops. I am worried the plugs are still heating up while its running. Any ideas? Not sure what to test or what to look for. Should I be concerned? GP's aren't that expensive but I don't want to cycle through them continuously at $10 a pop! .

We keep trying to come up with a name for the old girl but so far EVERY person that has seen her calls her the Beast so I guess it may stick. I had promised a couple of pics so those are attached. Thanks for your help in advance.

Dean
aka Tourglide
86 F250 4x4 4 speed project. (Turbo, FB, Small lift and 35's) Shes ugly but she's mine.

Beautiful bull nose

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The GP Relay for the 83 - 86 is known to stick on and burn up the plugs.
It is located in the left side (drivers) rear of the Engine.
87 6.9 thru 88 - 94 7.3 IDI the went with an up graded GP relay controller.

The 6.9 Controller screws into the engine block and is aluminum. I tried to
remove 3 different one`s at PNP, 2 snapped off and one unscrewed. I had
read of this happening, so tried first at PNP.

It sounds like your Controller is acting up.

I just wired mine to a momentary Toggle switch to activate the GP Relay manually.
Find a wire that is Hot (+) with key on, run it to the Toggle, and other side from Toggle
to where the Purple Wire connects to the GP Relay.
Toggle just activates the Relay, no big power going through it. Do put in a Fuse, maybe
3 amp or so.

You don`t have to use the GP`s once the engine is warmed up the rest of the day, unless
it`s been sitting several hours in winter conditions.

You can test the GP`s to see if they all work by using a test light. Connect the aligator
clip to (+) and with the spade connectors off the GP`s, touch the ends of ea plug to see
if the light comes on.
Having some not working or marginaly heating will make it difficult to start.


If it has the Block heater, plug it in for a few hours, if it starts right up with the block warm,
That for sure will point to the GP problem.
When it is real cold here I plug it in and in the morning she kicks right over w/o using the plugs.




Charlie

 

as Charlie said, the glow plug controllers on those old beasts were problematic and wound fail in the on position.
easiest fix is a momentary contact switch to control the glow plugs.
start at 5 seconds glow time and work your way up one-two seconds at a time to find your "happy time"
it should be around 8-12 seconds depending on how cold it is outside.

 

Thanks for the feedback guys. I am planning on an electric lift pump and plan to put a hidden switch on that to act as a theft deterrent. These old diesels get picked off out here all the time. I will move that up the list and install both switches at the same time.

holes in the roof are patched and primed - little bit o progress! Have a great weekend!

 

https://www.aircraftspruce.com/catal...statepump2.php
best e-pump on the market.
and the only one to use in my opinion.
they last damn near forever. i have one that is over 20 years old.
either one is good, i prefer the 40222 because of the higher pressure. if it gets too high, a pressure regulator is a lot cheaper than buying the bigger pump when you run out of fuel.

 

Facet is popular in this FTE forum, on Oil burners the Holley red is favored. I opted for the Holley Black with a regulator, never have to worry about a lack of fuel and can run bio or WMO if I had too. That's my .02

 

The main reason facet dura lift is preferred here is because it is a "sucker pump".
it will lift fuel straight up 10 foot so it can be mounted anywhere.
Most other pumps are "pusher pumps" and need to be mounted real close to the fuel tank.

 

One thing to note, on a fully-functional early style 6.9 GP controller, they have a built-in "afterglow" timer circuit that will briefly cycle the GPs on/off for a few seconds after a cold start, so some brief after-start cycling is normal on a cold start. Yes, the original electro-mechanical style controllers had some issues with sticking when they got old, but many of the new replacement types are a much improved solid-state design. Only drawback I've been able to see on those is that they can't be tested with a multi-meter like the old ones can.