I have a 1986, f250 with a 6.9. Never having owned a diesel before its been a learning process. The problem I'm having is that it seems weak, when I first got it it was a mess. So far I have replaced the muffler, (took the car muffler off) replaced the glow plugs, put a manual switch on because the controller was fried. Changed both air and fuel filters, cleaned both fuel tanks. It runs and starts fine, but it barely pulls itself up hills. I have a heavy trailer I would like to pull with it but it just doesnt have the power. As I asked around, one guy asked me if it would "blow black" when I stepped on it. I tried it and it doesnt really blow anything. He said it was probably a fuel related issue but didn't have any suggestion other than take it to a mechanic. Besides being limited on funds, I'm not the kind of guy to pay for something I could do myself if I have the proper info. Reading through some of the forums I've seen talk of turning up the pump, but I assumed it should be set right from the factory unless someone changed it. If anyone could give me some info on what to try first I would greatly appreciate it. Someone also mentioned a screen where the fuel line enters the pump may be clogged. That is the next thing I was going to check. Also can someone tell me where I can get a diagram or info on the pump. It would be helpful to understand how they work.

Thanks,

DRAPP127

 

To be safe you should probably post this in the Ford section I'm sure they'll be more than happy to help you out there.