Just bought a 87 6.9 f250 lariat 4 speed for 800 bucks and replaced solenoid battery and fuel filter and it runs like a champ. I do have questions. If it blows black smoke under acceleration has the injector pump already been turned up? There is a slight grey haze a idle an it smells like fuel not oil? I want to have good power but also decent mileage. How hard is it to turn the pump down if thats what it is? Also glow plugs arent working i dont know if its the relay or plugs. Sometimes i will here clicking like 8 times or so is that them trying to cycle? I have to give it a hit of ether(dont judge me) to get it cranked in the morning. Any help please. Also i ran it out of diesel today while figuring out one of the tanks is bad. I got it back started and it acts fine. Should i go ahead and crack the lines any way?

 

The fuel problem, it sounds like the return line is blocked, or the solenoid that opens is bad. Could also be the injectors are going bad to.

On the glow plugs, remove the harness off the solenoid, and use a battery charger to test them. What I mean is, hook the neg clamp to the battery, & touch the positive to the glow plug harness. If there is a little to no spark, need to replace all the plugs.

 

I am having problems with my tanks. I was told one of the tanks acts up. The switch says im on the back tank but the gauge is measuring the front and i am pretty sure that is the one im running off of. I would not be suprised if it was the return line. Where is it located on these trucks and can i just blow it out or something? Any other way to tell if it is injectors? It is definately burning rich and using a little too much fuel. By pluging the truck in over night could i rule any glow plug possibilties out?

 

Plugging will help, depending on the outside temp. The fuel selector valve is either shot, or it's not getting power. When it does lose power, it defaults to the front tank (I think).

Now the return line. It's located on the front of the injector pump. Might be a piece of rubber hose or a solid steel line coming off of it. You can remove the line, start the engine and see if fuel runs out. If no fuel, can remove the check valve and see if it dribbles out. If it does, the solenoid is either bad, or there is junk inside the check.

 

I gave up on glow plugs on my 85 ford with the 6.9 the either has worked just fine. Just remember don't use glow plugs and either at the same time.

 

The GP contirller could be bad, the 83-86 screw in head version had a habit of getting stuck open causing the GPs to burn out, in 87 with the new body style came the new motor the 7.3 IDI. Quite a few of the 87 trucks have a mix of parts from the 6.9 and 7.3. For example my 6.9 has the 7.3 solid state GP controller but has the 6.9 v belt system. What I wild do is pull the GPs and check them with a Ohm meter. And replace the burnt ones or all of them at once. But whatever you do stay away from Autolite or Champion GPs. They tend to burn out really quickly and I have seen many cases of the tips swelling up and bursting resulting in pieces of glow plug getting lodged in the Pre-Cup or cylinder. The best bet is to go and pick up a set of Motorcraft or Beru Glow plugs, I believe the P/N is ZD9, they are a lil more expensive but well worth the added piece of mind

 

I was able to purchase new Motorcraft GP's(ZD9) from an auto parts store and they were by far the most affordable at $5.60 each. Bosch and autolite were about $15 and the ACdelcos were $23. It could be worth your while to check locally before heading to the stealership. The place I went to only started carrying motorcraft parts a few months ago.

 

I wanna move there. It's the opposite here, the autolites are real cheap, then the motorcrafts are the most expensive

 

What would be involved in hot wiring the glow plugs to a button to heat them manually?

 

bump i wanna know too