injection pump problems

[lhypes]

Hi I'd like to thank everybody for there help last time.Got a new problem old injection pump went out I took off another pump and was running when i took it off i actually drove it and it ran great.So I put it on my 6.9 and I can't get any fuel up to where it comes out the lines got fuel to the pump.This is what i have done so far I ran a hot wire to the cylanode and open up the throttle to wide open and cranked at intervals and never got a drop to come out the lines.Don't know what i'm doing wrong maybe you gentilmen do?Any help would greatly be apperated.Thank you lhypes

[rsr911]

Don't know if the 6.9 is like the 7.3 as far as the filter housing goes but on mine (7.3) there's a schrader valve to purge air out of the filter. I'd start by pulling the supply line to the filter from the lift pump, crank the engine and see if you get fuel there, this will confirm whether the lift pump is supplying fuel. Put that line back on and if you have the schrader valve (looks like a tire valve) crank the engine while holding this open with a screwdriver (I ususally jumper the solenoid to do this). Once you have fuel there the system is mostly purged. I loosen the lines at the injectors and tighten each one as I start to see fuel.

Are you certain your injector pump was bad? Sounds almost like the lift pump isn't supplying any fuel.

[lhypes]

Originally Posted by rsr911

Don't know if the 6.9 is like the 7.3 as far as the filter housing goes but on mine (7.3) there's a schrader valve to purge air out of the filter. I'd start by pulling the supply line to the filter from the lift pump, crank the engine and see if you get fuel there, this will confirm whether the lift pump is supplying fuel. Put that line back on and if you have the schrader valve (looks like a tire valve) crank the engine while holding this open with a screwdriver (I ususally jumper the solenoid to do this). Once you have fuel there the system is mostly purged. I loosen the lines at the injectors and tighten each one as I start to see fuel.

Are you certain your injector pump was bad? Sounds almost like the lift pump isn't supplying any fuel.

Hi yes I put on a new lift pump i"m rebuilding this truck ground up so I know what I have.Thanks

[rsr911]

Well is the lift pump supplying fuel to the filter head?

[lhypes]

Yes I have fuel into the filter and I have at the pump I just can't get the fuel to the injectors?I just don't know what I'm doing wrong I'm afraid i'm going to burn my strater up.lhypes

[Evel486]

You stated you are building it from the ground up. Did you also replace the water pump at the same time?
With key on engine off touch the solenoid wire to it's terminal. You should hear it click if it's working.

[chuckster57]

Yes I have fuel into the filter and I have at the pump I just can't get the fuel to the injectors?

At idle the injector pump moves very little fuel. You can crack a line on the top of an injector and then with your foot to the floor, crank it. As long as you crank for 20 seconds and then REST THE STARTER for 2 minutes, your batteries will probably go dead first. It can take quite a while to purge all the air out of the system.

Did you also replace the water pump at the same time?
With key on engine off touch the solenoid wire to it's terminal. You should hear it click if it's working.

Did you mean the INJECTOR pump? then yeah you can test the fuel shut off solenoid on the IP. It is the FRONT tab on the drivers side top. With the key on you should be able to hear a "click" when you remove and then replace the wire.

[Evel486]

Water pump. The upgraded water pump for 6.9s is cast differently. If you mount it using the original bolts it will seize the injector pump.
At cranking speed the IP governor is in full fuel position. It does not start backing off until about 400 rpm. Pumping or holding the throttle wide open while cranking will make no difference.

[lhypes]

No the water pump is not new evel 486 what do mean in your last post so what i'm doing is wrong?I was told to run a hot wire from the battery to the solenoid and hold the throttle wide open to get the air out of the lines and get the fuel started.If this isn't right then i'd like to know the right way.When i said i was building from ground up i put on a new cab ,new box and alot of other stuff but the only thing that was changed on the motor was the lift pump and the injection pump the lift pump is pumping plenty of fuel i cracked the return line and got fuel.I'm kind out of options i'm only working on it at night when i get home everybody i talk to says just cranking it you'll get the air out.I just think that i should fuel by now? And yes the solenoid clicks.Lhypes

[Evel486]

Have you loosened the high pressure lines at the injectors? It's the only way to purge the air from the lines.

[lhypes]

Yes the lines are loose at the injectors and i can not get one drop out of any of them so we put abrand new pump on and same thing.I guess open for any suggestions?