So heres my story I have a 1984 f250 that the injection pump went out on, that I sent in to get rebuilt by dcp out of tennessee. well then I get my pump back and throw it on and bled the system and nothing so I sent it back got it tested they sent it back told me it was good maybe my injectors or i was not getting enough fuel no big deal I already had a set of brand new injectors from ford in the box and lift pumps arent to pricey. Put those on bled the system and again nothing. Now I am getting 5-6 psi of fuel to the injection pump while its cranking from the lift pump and im getting fuel out of the injection pump from the injector lines to the retun line on the pump but im not getting fuel out of the return lines on the injetors

 

I can see its going to get messy!
I don't know how the ford set up their pump so bear with me.

So I read this right you are getting fuel from lift pump (5-6psi) to inject pump.
Then I get a little lost, you are getting fuel from injector pump lines to return lines on pump?
Then you say you are not getting fuel out the injector return lines?

So are you getting fuel out of the injector pump at each line for the injectors at the pump?
Are you then getting fuel out at each injector at the fuel in port?
Are you getting fuel out at each injector for the fuel out (return) port?
Then where ever the injectors returns come back to are you getting fuel there?

I am thinking you need to bleed at each injector because the air trapped in the lines to the injectors is compressing and will not let the fuel reach the injector to push it open.

I had a Chevy 6.2 diesel and I cant remember if it had returns at the injectors, don't think it did so the fuel would work its way thru when I changed out the pump the 1 time I did it.
Good luck and let us know how you make out.
Dave ----

 

ok so i tried to bleed it again no air out of the injectors but when I pressed the schrader valve on the filter head it had alot of air in it before any fuel came out of it. then when it sits for a couple minutes and you press it again no fuel comes out

 

If you crack the hard line connectors at the top of each injector and crank the engine you should eventually see some fuel seepage at the top of each injector. Then tighten them down but leave one or two cracked that are easy to get to and crank the engine. It will start and run with one or two of the hard lines cracked open to bleed the last of the air. After it is running get out and tighten them down. Until you get fuel at all 8 hard line/injector junctions there is still a lot of air in the system and it will not start. Be sure your batteries are charged up, as you will need good cranking speed to get it to start with a little air still lingering in the system. And let the starter cool down in between tries. It's easy to kill batteries and starters this way... Ask me how I know Ether can help as it will run briefly on the fumes before you get good fuel delivery but be sure to disconnect the glow plugs if you do this, and spray the paper filter not down the intake.

Edit: if you still have a lot of air in your filter it may be necessary to crack it slightly while someone cranks the engine. It can have so much air it won't bleed through the IP and hard lines. Just be sure to wrap it in a rag or when it fills it will spray fuel all over your shirt and the engine bay... Ask me how I know

 

ok I tried bleeding the system there is no more air coming out of the injector lines and im still getting nothing out of the returns I put some fresh oil in the glow plug holes thinking it had cylinder wash but it fired right up until the oil ran out and still no fuel coming out of the returns

 

I would put more oil in the cyl so it will fire off again but before you light it off open some of the returns (3) at the injector and others open the supply (3) injectors and leave some both sides (2) closed and see what you get.


Also do you have a way to pressurize the fuel tank say 5 to 10psi at most when doing this?
Dave ----

 

Thanks I will try that again but i do not have a way of pressureizing the tanks but i do know that one is completely full

 

Be careful putting oil in the cylinders. Over do it and you could hydro lock it. The IDI has piston oilers, this cyl washing thing is not a concern. Don't worry about seeing fuel in the return lines. At cranking speeds the lift pump will fill them very quickly at all. Just worry about getting the air out of the filter head, IP, and hard lines. If those are bled correctly and your pump timing is close it will start and run.

 

Don't worry about the psi on the tank(s) just thinking it may help "push" the fuel thru the system. I had to do that on my 6.2 when ever I changed out the filter.


I still think there is air in the lines. I would not worry about no fuel in the return lines just fuel at the injectors supply lines.
Dave ----

 

Some people install a marine primer "bulb" inline after the lift pump to prime the filter. Many also opt to bypass the mechanical lift pump and put an inline electric fuel pump. However, the factory set up is just fine if you bleed it correctly.

 

ok so i found out the pump that was on it was for a 7.3 which shouldnt matter but the company sent me a 6.9 and i put it on and it is doing the same thing so far. i should mention to that it did have a timing adaptor on cylinder 1 before on of the lines broke then i replaced them all would that matter?

 

The hard lines with the adapter on No. 1 cyl are from a 7.3, you can run either set just don't mix and match as they are slightly different lengths and some cylinders will be slightly out of time with the others. 7.3 pump is fine on a 6.9.

Just to make sure, when you changed the pump you didn't remove the pump housing and gear did you? Are you getting fuel at the injector hard line ends?

 

Any white smoke out the exhaust?

 

So I didnt remove the housing on it at all, I just removed the 3 bolts. the weird this is im not getting any smoke out of the exhaust right now at all

 

When you are cranking do you have it at full fuel, wide open, foot to the floor?


I wouldn't be worried that you aren't getting anything out of the returns, the question is fuel getting to the injectors, returns will take care of themselves. Me I'd skip the fuel system before the filter at this point and just run a hose to the filter from a fuel can on the roof of the truck and an electric or hand primer(bulb) pump. Then bleed(without cranking only fuel flow is needed) step by step, at the filter, at the line into the IP, (maybe at the IP taking the top off) then remove the injectors and put the lines in like shot glasses instead. Open the throttle and crank till the shot glasses have fuel in them.