Well I replaced the injector pump. Now it doesn't want to start. It started once but only after a ton of cranking. It ran very smooth. But when I went to re-start it it would not start.

Last time I had it on the road before I changed the pump it died going down the highway. I suspected a lift pump or filter.

So now I've replaced the injection pump and filter. I left the lift pump alone because it's spraying hard. I've checked and it's getting fuel to the injection pump. But I pulled an injector an it pulsed once then no more fuel has came out. I've cracked all the lines I can get to but no fuel is coming out. The rebuilt pump came from Pensacola Fuel injection one of the links that someone posted when we determined I had a weak injection pump.

It did studder and almost start again once after I had cracked a few injector lines. So I'm not sure whats going on now. I know there is no fuel right now coming out past the injection pump. Also when it did come out that one time it just kind of pulsed at low pressure when the line was clear off the injector. Is that the way it should be coming out of that injector line?

So I either have an injection pump that doesn't want to prime or is bad??


Thanks again,



Jeffro

 

Lift pump, I got my 7.3 for 500.00 for the same reason...Guy couldnt get it started after changing IP,Glow plugs,Starter,Batteries,Filter then gave up...He was paying a diesel mechanic 60.00 and hour,1200.00 later.....I got it put in a new 25.00 lift pump and it fired right up!

It was pushing fuel but would build pressure.

 

Thanks! Sure worth a try. But If I can actually see the injector pump getting fuel to it the lift could still be bad? Wouldn't that injector pump suck up what was ever available.

I have also taken off the return line at the pump and it has fuel coming out of it. I checked both of the 12V electrical connections and they are also getting fuel.


Stumped but I think it's going to get a new lift pump no matter what this particular problem is.


Thanks,


Jeffro

 

My guess would be the pump arm still makes the pump move fuel even when the bladder breaks, A gasser pump has holes in the side so when it breaks the bladder it leaks fuel...Since diesel is an oil and wont dry up like gas they didnt want oil pumping out of the pump?

 

The lift pump on these engines also have a vent hole on the side of 'em, and usually when the pump goes bad, it leaks from that vent hole.



That, or fuel gets into the crankcase...

 

I wonder if a spring inside breaks then?

 

Usually it's just the old diaphragm that breaks.



Same thing on a water pump, usually when they go bad, they also leak from the vent hole.

 

UPDATE PROBLEM FOUND!

The 12 volt fuel shut off switch on the top of the pump failed in the closed position.(On a new rebuilt pump)

Put my old unit on the new pump and it fires up like new.

So if your ever not getting fuel to the injectors that is sure a good thing to check.

Thanks for your help!!

 

so thats the cover on top??? were there springs and stuff ready to pop out?

 

Yes it's the top cover. Three small bolts coming directly out of the top. It houses two little electric servo things (I'm no Electrical wizzard and I can prove it! Lol) The top comes off and the servo's were submersed in diesel fuel. The gasket comes off with the top cover.

The front one (cloestest to the fan) is the "fuel shut off switch" The back one is the "Cold idle" switch I believe. I just grounded the top cover and put 12V to the exterior male plug and the servo should move open. If they don't, it's junk. Like my new one!! It cost me a starter and an extra day off of work but the pumps going anyway.

So to answer your question, no springs tried to pop out there were some down in there but they were going horizontal and looked to be pretty stable. I just took the old cover with the servo's off my old pump and bolted them up. It fired right up!!!!


Let me know I can post you some pics if I haven't described it good enough!!



Jeffro