OK, yesterday I had 5 batteries hooked up. Two 1000's in it along with jumper cables to my 87 F250's two batteries and another set to one of my Bronco's battery. I added a second cable from the battery to the starter. It does crank a lot longer with all those batteries hooked up but it still won't start. I still think it's the dry cylinders causing the drag on the engine as when I get a little fuel in there it will definitely start to crank a lot faster and I start to get a little mist/smoke drifting up out of the intake. Back to my original question, could the injector pump be so shot it won't even start? I turned up the pump with the screw in the back to try to get more fuel. I have plenty of fuel coming out of the filter's Schrader valve. If I take the small return line off of the filter assembly where it clamps on next to the Schrader valve and crank it fuel will come out of the nipple in a steady stream even after I stop cranking it until the pressure drops but none comes out of the rubber line. If I take the rubber line off of the brass 90 degree nipple on the top of the injector pump and crank it just a small dribble will come out of the 90 but none from the rubber line. If these are the return lines shouldn't fuel be coming out of them instead of the nipple or hose barbs?
A screw in the back of the pump with a locking nut at it's base and a plastic safety cover I had to remove to get to it. The one on my 87 looks the same but had safety wire seal instead of the plastic cover. Isn't that the screw to turn up the pump pressure?
Have you tryed disabling your glow plugs and trying starter fluid? I have diesel tractors that get real uncooperative in the winter. The tractors have manual glow plugs so I have the option of not using them. In your truck it is automatic. Pull the hot wire off of the glow plug relay and try a squirt of starting fluid. If it starts that would seem to indicate no fuel is getting to the cylinders.
I've not tried that yet. But my late father that was a mechanic used to tell me about using starting fluid on a diesel "When you think you've given it a tiny amount of starting fluid, it's already twice too much" So, I've been cautious about using any yet.
Dave, after a little research I also found that the correct screw is inside the pump and while I took that plate off I didn't see it because I now know the pump has to be rotated to see it. I turned the screw on the back in 1 turn so now I'll turn it back out. I still think the pump is shot though as there is very little fuel coming out of the injector lines. What about my question in post 17 where I said I have a little fuel coming out of the fittings on the filter and on the pump instead of the return lines?
I am not completely understanding what you are saying, but here is my attempt to answer it anyway.
The return lines return excess fuel to the tank.
So no fuel should be coming out of the rubber lines.
There are supposed to be check valves in both of the fittings you mentioned, but they usually don't work very well.
Have you checked the pressure at the schrader valve?
You should have about 5 PSI there while cranking.
And reading through everything again, my guess is you are due for a new starter.
That many batteries, still cranking slow, then speed up after you crank for a bit, that sounds like a starter.
Lubrication in the cylinder from fuel, that is not going to affect cranking speed with a good starter.
If the engine is not cranking over fast enough, it will never start.
I actually took the starter from my 87 F250 and swapped it with the one from the 88. Both starters do the same thing. They both start my 87 6.9 just fine and they both crank slow in the 88 7.3. I took the rubber line from the fitting on the filter assembly next to the schrader valve and fuel came out of the fitting in a strong steady stream while cranking. I took the hose from the 90 degree nipple on the top of the injector pump and just a dribble came out of that fitting while cranking. I'll check the fuel pressure at the schrader valve tomorrow but I get a lot of fuel out of the line to the injector pump while cranking but very little out of the injector pump lines to the injectors.
you ever get this figured out? im having a similar problem. no fuel to the injectors, plenty of fuel to the ip. solonoids all seem to click when jumping them to b+ . i have an electric pump and when u pull the return line from the ip. it will drip very slowly without 12v to the fssw and will drip a tad bit faster with b+ to the solonoid. i am told it should be a steady stream comming out of the pump , if i remove the return line from the filter up top it sprays out like a squirt gun sized stream steadily.
the engine cranks over a bit slower than it should be (maybe 100-150) rpm. but it is bone dry comming out of the hard lines to the injectors. i figure it should still put out some ammount of fuel even if its cranking slow. i think its time for a new ip. and i may as well replace the injectors while im in there.
No I didn't but I've not had time to mess with it lately either. When I get a little fuel in the cylinders it starts cranking faster. I still say the slow cranking speed is due to no fuel in the cylinders at all and since they are so dry they have more drag and therefor it's harder to turn over.
even if it was cranking a bit slow shouldnt it hypotheticly still squirt fuel out of the pump? any possibility that both pumps are bad?
im having an almost identical problem and im about to try a used ip. (i have 3 total) im going to try all 3 and see but i have a feeling that im going to end up ordering a new one with new injectors from pensacola diesel.