Hello all,
I have an 87 f-350 with 7.3L. I have great fuel pressure all the way to the injection pump but nothing but a couple drops coming out the lines to the injectors. I tested the solenoid on top of the pump and it is working.
The odd thing is,... sometimes it will start. Then runs pretty good until it sits all night. But when it will not start I have no fuel pressure past the injector pump.

I know I am doomed (injection pump time) but in the hopes of something I missed. Is there any other reason I would not be getting fuel to the injectors intermittently?

Thanks for reading

 

An air leak somewhere in the fuel system causing the fuel lines to lose prime will cause your problem. It doesn't have to leak fuel out to get air in.

The lift pump may be very weak. Check engine oil for fuel dilution, a bad lift pump will add fuel to the oil though the broken diaphragm.

 

Thanks "Mistaken" for your reply,

I have an electric fuel pump on the frame as well as the mechanical pump. I have no leaks and I have great fuel pressure to the IP. After the IP nothing.

I will check the oil for fuel,.. in fact right now.

Thanks for the tip.

 

A bad lift pump will not always put fuel in the crankcase. It does sound as if you have a leak somewhere. The last one I repaired had a leaking tank switch. Push the bleed valve in the morning and have someone crank it over, if you don't have fuel right away you have a leak. Does sound like a pump thou.

 

No fuel in the oil,... Just won't put fuel to the injectors. Not at all now.

 

Thanks "lenzhotrod",
I have great fuel pressure through the filter (including bleeder valve) and to the IP. There is no pressure "after" the IP,... at all.

 

It does sound IP related based on the information given. If you run the e-pump for 10 seconds before starting and it doesn't fire off quickly, then you can be sure it isn't a leak causing the issue and you are looking at an IP replacement. Even with leak back, it should fire off after a crank or two.

If you replace the IP, you need to replace the injectors, too. It is pretty critical to do both at the same time of you like MPG and HP. Have the timing set as well.

 

Thanks eatont9999,

I was reading your problem as well and came to the same :-( conclusion.
I appreciate everyones input! I will post the solution when done.

 

I could be wrong, but I thought I once read here about a screen at the IP inlet that was blocked up with junk?

 

bio-d,

Could that be true??
I guess I will find out when I take it off Monday. I will be sure to watch for that first.

Thanks for the tip.

 

I don't know about a screen, but the '87 in the signature keep cutting off aprox. 1/2 hour of running; always the same, highway speed let off fuel for decel or turn OFF. Hard start. Man runs a diesel shop told me over the phone to try this $25.00 a quart cleaner he had. Someone here, I think said try new filter with ATF. I filled new filter with 50/50 mix Diesel clean and ATF then accidentally poured 10 gal. hi sul off road in the tank. So far she has cut off once in 500 +- mile of driving short trips. Try cleaning her out first. We were using 5% Bio mostly before that. Now were are adding ATF to fuel. We generally change fuel filters every other oil change -aprox. 10K.

 

i hate when that off road#2 spills like that

 

What kind of cost are we taking about for a new IP. What about the cost of rebuilding them?

 

Ha HA