Hello all,
I just bought an '87 f250 with the 6.9. It wasn't starting and I got it for what I think is a pretty good price.
The old owners have been having a hard time getting it to start lately, and claim it just wont stay primed. There is an awful mess of a vegetable oil conversion on this thing, real half assed, barebones and a wiring and plumbing nightmare. However, they have had a local reputable mechanic working on it up until a few months ago and he has been over the fuel system and claims there are no air leaks. He suggested a weak injection pump or leaks at the return caps on the injectors.
When I went to check it out at the previous owners place the veggie oil line up past the veggie oil filter was full of foamy water, so Im assuming at some point this engine was fed some swampy mix of water and oil... wonderful for the pump and injectors Im sure.
So, in my about 2 hrs of trying to get this beast to start here is what I have found thus far:
Fully charged the batteries for maximum cranking power.
Diesel tank has fuel, hard fuel lines were replaced a few years back.
Very new glow plugs operate on push type switch on dash, run off stock relay, no reason to believe they are shot...
Relatively new lift pump is working, getting fuel flow right up to the hard line that goes into the IP. I even installed a low psi electric pump after the filter, right before that hard fuel line to ensure adequate fuel delivery to IP.
Shut off solenoid is working with key on, I hear an audible click when removing and replacing the wire clip.
No fuel at injector line when cracked and cranking.
My conclusion is that unless there is a clog in the hard line that feeds the IP, I may be looking at a bad injection pump.
Pulling this part and replacing it actually looks quite easy, but before I jump into a $400 project I want to make sure I have diagnosed this correctly.
Any ideas or suggestions would be very appreciated!
thanks,
- Ben
I just bought an '87 f250 with the 6.9. It wasn't starting and I got it for what I think is a pretty good price.
The old owners have been having a hard time getting it to start lately, and claim it just wont stay primed. There is an awful mess of a vegetable oil conversion on this thing, real half assed, barebones and a wiring and plumbing nightmare. However, they have had a local reputable mechanic working on it up until a few months ago and he has been over the fuel system and claims there are no air leaks. He suggested a weak injection pump or leaks at the return caps on the injectors.
When I went to check it out at the previous owners place the veggie oil line up past the veggie oil filter was full of foamy water, so Im assuming at some point this engine was fed some swampy mix of water and oil... wonderful for the pump and injectors Im sure.
So, in my about 2 hrs of trying to get this beast to start here is what I have found thus far:
Fully charged the batteries for maximum cranking power.
Diesel tank has fuel, hard fuel lines were replaced a few years back.
Very new glow plugs operate on push type switch on dash, run off stock relay, no reason to believe they are shot...
Relatively new lift pump is working, getting fuel flow right up to the hard line that goes into the IP. I even installed a low psi electric pump after the filter, right before that hard fuel line to ensure adequate fuel delivery to IP.
Shut off solenoid is working with key on, I hear an audible click when removing and replacing the wire clip.
No fuel at injector line when cracked and cranking.
My conclusion is that unless there is a clog in the hard line that feeds the IP, I may be looking at a bad injection pump.
Pulling this part and replacing it actually looks quite easy, but before I jump into a $400 project I want to make sure I have diagnosed this correctly.
Any ideas or suggestions would be very appreciated!
thanks,
- Ben