Deadbunny

91 D250 Cummins

Need help quick.

I ran out of fuel a few days ago and have been trying to get this **** thing to start again. Iv bleed the hell out of the system 5 times already and it is still pushing out masive amounts of air from the injector lines. No where in the fuel system or the IP does it leak fuel so all I can think of is that the air is coming from the boost line. I don't know

I installed a purge bulb and bleed it all the way up to the IP so I know Im not getting air from the tank or filter.

Iv tried bleeding the injector lines several ways from just loosening the injector lines to pulling them off and letting them blow fuel freely to putting clear nylon tubes in the lines so I could see the fuel and air come out.

When I put the clear tubes on the injector lines I watched them push out massive amouts of air. It pushed out so much air that I killed a battery with a fresh charge. I don't know where this air is coming from. Its not coming from the feed line.

Is the IP screwed up? I need help fast. My rig is sitting in a parking lot and the town police are not too happy with me.

Totallyrad

Assuming you've got plenty of fuel in the tank now, check the fuel filter. If you changed it or opened the drain on the bottom, you could have messed up the seals or left the drain open. Also, just curiosity on my part, check your oil. If the stock pump has a bad diaphragm I think it could be dumping fuel into the crankcase.

Deadbunny

I'll check my filter.

How and which pump would be dumping fuel into the crank case?

Totallyrad

The lift pump. I believe the stocker is like the old Chrysler V8 pumps, cam driven. If the diaphragm fails, the fuel will dump into the block.

Totallyrad

Also make sure you didn't knock the wire off your fuel cut off on the injection pump.

https://www.dieseltruckresource.com/...5&postcount=19

Deadbunny

just checked the truck. Wire is still on the solenoid and fuel is still passing through the high pressure lines so thats not the problem.

there's no fuel leaking out anywhere near the filter or drain **** so thats not it. Irregardless the the feed line to IP is free of air, eliminating the filter and LP as my culprit.

Oil is still at the same level when I last checked it, just below the "safe" line. So there's no fuel passing into the crank casing.

However I did find the manual fuel primer on the side of the lift pump. I pumped it and it doesn't work. I don't know what significance this has as the diaphragm lift pump still pushes fuel through the system.

D2 Cat

I'm not familiar with your engine, but you might have a problem with the manual primer. To find out disconnect the in and out lines (at the primer) and connect them with a short piece of hose or a hose barb if they're long enough to reach each other.

Deadbunny

I do have a problem with the manual primer. However its not effecting the lift pumps operation, i.e. the lift pump works, so Im ruling it out.


All I can figure is, air is getting into the IP form somewhere that isn't the fuel feed line.

I don't know, maybe the air is coming in through the KBS, fuel return or boost line. Im not sure how that would happen. Im not totally familiar with VE pumps.

duner

maybe you didn't actually run out ot fuel in the first place. just a thought.

Deadbunny

At this point I think you might be right.

rattlerbob5.9

The manual prime lever will NOT work if the engine has stopped on the high spot of the cam. The lever will feel like it is just flopping around.

You are not getting air from the boost line

With a FULLY charged battery slightly crack the fuel line from the filter feeding the inj pump roll it over and see if you have good fuel there. if it is ok close it then slightly crack 3 lines at the injectors and roll it over to purge them.

Close the first 3 and then open the last three roll it again and purge those.
Close them and make sure your battery is fully charged put your foot on the throttle push it a good 3/4 down and try to start it.

It should try to start now keep your foot in it enough to keep it running it will run ruff for a little while and then straighten out.

You need to have a good battery with a high amount of charge in it to spin it over fast enough to start

Deadbunny

So I tried again today.

I took the return line off the IP and watched a poop load of air come out of it.

I get the feeling there is a lot of air still trapped in the IP.

What my next question is, is there a valve or something else to purge the air from the IP? It doesn't make much sense that the air trapped in the IP would be properly evacuated out of the injector lines at the bottom of the IP while air would stay at the top of the IP.

wannadiesel

You are getting air into the IP from the fuel system. Check your lines very closely.

Deadbunny

The air is not coming from the fuel system. I pushed roughly a gallon of fuel through the LP, filter, and low pressure line all the way up to the IP with an in-line purge bulb.

there is no way in hell there is still air in the system before the IP.

Deadbunny

Oh and I forgot to mention. Rattlerbob is right. My manual fuel primer does work.