Did I buy the wrong truck?

Without too long of a story, I decided I decided I wanted a truck to use to haul a slide in camper for camping trips and to use for other truck things the rest of the time.  After looking at a bunch of trucks I decided a full size diesel Ford seemed like the best option, because I am too tall to sleep in a camper in a smaller truck, I drove a Chevy and didn't like it, and I can't affford a Dodge.  I looked at a dozen Fords over a year and finally bought an 87 F250 with a Banks turbo kit that has no rust and under 100k miles as far as I know.  I drove it hope ~3 hours with no problem, but it was from out of state and I had to wait a couple months to get it registered and insured, and in the time it sat in my driveway the fuel system has failed and it will only run a few minutes at a time.  It looks like the next step is to pull and clean the fuel tanks and start changing seals and gaskets all the way up to the front.  I don't have a way to take the bed off, and it's cold and wet outside and I am feeling less and less excited the more I think about it.  Time to get rid of it and try again?  Or is it not as bad as it sounds.

It's pretty tough to get a slide-in under your weight limit with a 3/4 ton diesel. What's the capacity on the sticker?

The slide in I want is around 950 lbs, new ones are $40k but part of why I wanted this truck is that it's what people are using for older ones of the era I could afford.

One of these, but an old one since they have made them for 50 years and you can get 90s ones for $5k.  https://fourwheelcampers.com/model/grandby-model-pop-up-truck-camper-leader-full-size-trucks/

I have kind of learned the hard way when buying an older diesel truck, be sure to budget some amount of money to make the truck actually reliable. Possibly a similar amount to what you paid for it. Or in the case of both older diesels I've bought ('95 Cummins and currently a '92 Ford E350 7.3 IDI), substantially more than I paid for them.  Most of the time, there's a reason the truck was sold in the first place and now you have to figure out why and hope it doesn't cost too much to fix it.  

To be honest, I bought the '92 Ford not because it's a diesel, but in spite of it.  I feared it would be a PITA and unfortunately, I was proven correct.  But the van has other attributes I wanted and the price was right.

My dad had a 6.9l with a Banks turbo.  Was bulletproof after the porous heads were replaced. 

First, change the fuel filter.  If it runs fine for a while and then dies, your fuel may be contaminated and need to be drained.  I do not remember if there is a pump in the fuel tank.  I'm sure someone here will know.  I suppose you could pull the fuel filter, put a catch bucket below it, and turn on the key...

You should be able to tie into a fuel line and use an electric pump to drain the tank without pulling the bed.

Add new fuel and another fuel filter and run it.

In reply to CJ :

An '87 should have a mechanical lift pump on the block.  It feeds the injection pump 3.5PSI (I think) to allow the injection pump to maintain proper pressure to the injectors.

Worked on several DB2 injection pump engines in the USAF, always seemed to gravitate to me for some reason.

It sounds like it might be losing prime somehow.  I'd clean all the fuel line connections of dirt and grease, bleed the system to get it started, clean anything that got diesel on it while priming the system, then I would start it and let it run while checking the fuel system for leaks.

It looks like it has a lift pump on the engine similar to a mechanical fuel pump on a gas engine, there is also a electric valve to switch between fuel tanks.  I tried to remove that to replace it with a new one but I can't reach the fuel lines between the tank and the to disconnect them.

Mr_Asa said:

In reply to CJ :

An '87 should have a mechanical lift pump on the block.  It feeds the injection pump 3.5PSI (I think) to allow the injection pump to maintain proper pressure to the injectors.

Worked on several DB2 injection pump engines in the USAF, always seemed to gravitate to me for some reason.

It sounds like it might be losing prime somehow.  I'd clean all the fuel line connections of dirt and grease, bleed the system to get it started, clean anything that got diesel on it while priming the system, then I would start it and let it run while checking the fuel system for leaks.

It is sometime hard to start, sometimes will start right away.  It will idle for as long as I leave it running, but will only drive for a few minutes before slowly losing power and dying, then it will start again after cranking for about 30 seconds and do the same thing again.

So the DB2 injection pump shuts off the engine with a solenoid opening a check valve in the pump to drain the pressure within the pump to 0PSI, then the injection cycle doesn't work.

If the lift pump can't supply that pressure, it should show up with similar conditions that you are listing.

Now, what is causing those conditions could be several things: failing pump, clogged filter(s,) hole in a line, check valve damage, or even something in the tank.  Even the water separator not being closed all the way can bleed off pressure.  I'd just start with replacing the filter and checking the lines. 

If it is running at all, I would think the injection pump itself is good, so I would focus on the lift pump.

I forget... do they have the canister filter on top of the engine like the 'strokes?

If so, buy a new filter.  While the old one is out, disconnect the supply line from the tank and the lift pump.  Blow it out with compressed air taking note of what comes out.  If it looks like the "mother" in a bottle of grandma's vinegar or the bottom of a Kombucha bottle, then pull out the tank and clean it.

Taking off the bed is 6-8 bolts, a couple wires, and four people.  Not as big a deal as a lot of people assume.

Start small.  Several glugs of diesel treatment in the tank and test the lift pump pressure first.  Possible (but unlikely) that you have some algae growing, but my guess is bad lift pump or clogged filter.  I think you'll find with these Internationals, it's never as bad as it seems.  They're remarkably simple and very robust.

As Curtis says, lifting the bed on that is quite easy. I also found that dropping either tank was quite easy as well!! 
Easy enough, that I'd recommend dropping the tanks, cleaning them out and replacing the pick up strainers. I've had them cause some problems, and it'd be nice to have known good pick up screens. 

It does have a spin on filter, i changed it and it ran a little smoother but otherwise it didn't help anything.  It sounds like pulling the fuel tanks and pretty much replacing or cleaning everything up to the injection pump is what it will take.  I know it's fixable but I am having a hard time staying excited about it when realistically it will be 6+ months to even drive it around the block when it worked fine when I drove it home. Oh well.