1986 Ford 6.9 diesel………

Good low end power but a little doggy.   Pulled 5 loads of rould bales yesteday.  Handled the job well.

I did away with the glow plug controller curcuit over twenty years ago.  To energize the glow plugs, I use a deadman push button.

I suppose everyone's experiences are different, but having seen the treatment Peg, Sawedoff & the like give the old IDI's on youtube I know exactly what truck I'd be buying if I ever landed up that side of the pond.  Peg @ Zip ties 'n' bias plies has just recently done something like 3000miles cross country in a 6.9 with questionable head gaskets, just kept adding eggs & hammering down some more, it survived OK. 

And if you've ever seen his old 7.3 (nicknamed "slave lake" after the fire there, because of the smoke) you'll know it's been run hard on the ether and cold redlines for many years now, even ran it without coolant for a good while. Only the last year or so has he put working GP's in it...  Plus being IDI it'll run on anything vaguely flammable.

(Plus if it ever failed, I'd just offload it to one of those minty fellas)

  Actually the 7.3 has an excellent reputation right behind the Cummins.

6 years back i found a 1984 F-350 with no title bought it cheap put the straight front axle under my 83. Never did like the twin I-beam suspension under them. The 350 i bought had low gears in it but I only haul firewood and can drive to work on gravel roads, and I am older than dirt, so I get in no hurry.

3 years back we did a complete off frame restoration on it.

I will be buried in this truck....LOL.

has had a flatbed on it for years much better for what i do.

I purchased a very clean 1984 F-250 w/6.9ltr diesel engine when I was right out of the Navy for the economy of operation. Good looking truck, but really lacking power as it was geared with a 3.08 ratio rear axle. Driving home and without warning, the engine started "knocking" in the lower end hard enough it could be felt through the accelerator pedal. Coasting to a stop into a parking spot, it sure was knocking. I'd had the truck three weeks to the day at this time. Oil was full but a lot of bearing material in the film. After towing it home and pulling the engine, long story short is both heads were busted, one head gasket blown, crankshaft and two rods destroyed. This was all replaced and engine rebuilt lasting another 13K miles before oil pressure once again dropped to zero, (indicated) to where I shut the engine down immediately as I was rolling to a stop. After towing home and lifting the engine from the chassis, once again the bearings were found destroyed.

Both of the failures were from the engine oil cooler which had a bypass valve built into the end of it. Both times, this valve was partially stuck open bleeding lube oil pressure from the oil pump and instead of pushing it through the cooler, was dumping right back into the sump starving the engine internally. This valve was replaced with the first rebuild and all oil passages cleaned with both hot tank, and physical brushes. I rolled new bearing shells, and cam bearings into the engine as the babbit was worn from the cam bearings, measured everything up, and once again replaced that relief valve in the cooler. I only kept that truck another 500 miles and then sold it to a guy that just "had" to have it. I gave full disclosure of what I'd been through with it and was very transparent. Though running very well while he owned it, the engine did not last a year before it let go on him hauling square bales. He had changed the rear axle as it had no power to pull with shortly after I sold it.

I seen him in a cafe' about a year later getting filled in on what he'd been through with that truck and it really wasn't pretty. It was parted out as he had other Ford trucks in the family and the frame being made into a sprayer trailer. He was then driving a then new GMC truck.   

Myself, I think once the head gaskets and bolts were replaced with the then new graphite gaskets, the repetitive blowing of them seemed to cease. I believe the 7.3ltr engines that replaced the 6.9ltr in 1987 had the graphite gaskets originally, but still had the weaker head fasteners and once addressed, were a pretty sound engine. Those are quite highly desired these days being all mechanical and if either a Banks, or ATS turbocharger system is incorporated, a lot of power can be had from them. 

Timing relays/contactors for the glow plugs on the IDI engines were not very long lasting. Usually bypassed them with a firewall mounted 100A Cole-Hersee continuous duty solenoid switch and push button operator.