Need help with Bosch Injection Pump on Case 590 Backhoe with 4BT Cummins

Here goes...Hoping you guys can help me. I have a 1996 Case 590 Backhoe with the 4 cylinder cummins with the Bosch VE pump (pump number is 0 460 424 081. Last year, the machine shut off on me while working. Upon further review, my fuel lift pump went bad. No big deal, ordered a new one and right back in business. A year later, same thing again, it just died. So I grabbed another lift pump, primed it, purged air, etc.... Cranked the engine and I am getting nothing. I checked the fuel shutoff solenoid and it works fine and I even installed a new one just to be sure. No change. At this point, I would like to figure out next diagostic steps. I was going to hook up a pressure gauge to the injector outlet line to confirm the pump is pumping the right pressures. I cannot find any data to confirm what the output pressure should be to each injector. I am also thinking it may have skipped time. I am getting black smoke out the exhaust when trying to crank it over but its not even trying to fire up. Any help would be greatly appreciated.

You need to verify that you have pressure going IN to the injection pump. Then you pretty much trust the pump to do it's thing or pull it off and have it fixed if it doesn't.

Were you getting black smoke while cranking since it died on you? or only since the new lift pump? I think you're close to getting it started, just still a little air to work out.

Thanks for the response. I know I am getting fuel from the lift pump thru the fuel filter and to the pump (I cracked the inlet line when pumping the lift pump lever). It dripped/spurted out of the inlet pump line. What should the inlet pressure be to the injector pump. Maybe I put a gauge on that. I found some data that the injector outlets to the injector should be around 1750 psi range. We've cranked on this engine for hours and we are getting black smoke out the exhaust but no fire at all.

The lift pump is flowing fuel thru this inline filter with no issues.

Does the fuel shut off solenoid have power while cranking?

Also, if the engine does not spin fast enough while cranking, they may not start either.....

I do know that the solenoid actuates up and down when I turn the key on and off but I did not check if their is voltage during the ignition cranking stage on the switch.

Yes, be sure it has voltage WHILE CRANKING..

Delmer said:

Were you getting black smoke while cranking since it died on you? or only since the new lift pump?

Click to expand...

And did you diagnose the bad lift pump, or put the new one on out of habit?

How about the air? Pull the hose of the intake manifold, or test the "boost pressure" with a pressure/vacuum gauge. Any chance there's some load on the hydraulics or transmission? I don't think I've ever seen a diesel blow black smoke while cranking and not start.

It's possible to slip time, just not likely. The outlet pressure is not practical to test, the testing procedure measures the output of each line under pressure. You can pull an injector and see if it's spraying, but since it's blowing black smoke, I wouldn't do that yet.

The feed pressure up to the injection pump should be about 5psi or better..
YOU cant test the injector opening pressure unless you have a pop tester and their done 1 at a time outside the machine..
You CAN however take them out, turn them and hook them back up outside the machine to SEE if they are popping/opening up.
Have you loosened all the lines AT the injectors to see if the pump is pumping fuel UP TO the injectors?? Black smoke is an indicator but what the hell, why not try.

Thanks for all the feedback so far guys. I replaced the lift pump purely out of habit since the last time this happened, it was the lift pump. It was a $20 cheap fix but it obviously didnt fit my problem now. I will do the following today: 1. Check to make sure I have 12 volts to the shutoff solenoid during cranking. 2. I will re-purge the fuel inlet line at the pump. 3. I will crack open the lines at the injectors and confirm the pump is pumping fuel up to the injectors. Maybe I just need to purge the air better and do some more engine cranking to purge it all out. All fuel ilters on the machine were replaced with new ones when I put the new lift pump on the other day.

Just saying low fuel pressure is what kills those little priming pumps....
be sure to blow back thru your fuel supply hose and drain the water out of tank
on a regular basics...

Sure sounds like the same problem we had but on a older backhoe. Ended up being the rack in the pump. Your on the right forum though... these guys can help figure out just about anything.