Good evening I am new to community but am having some serious issues with my 93 barth 8.3 cummins and i cannot figure it out. It will not start on its own. It used to start and run fine. I have already drained and cleaned fuel tank, put new fuel and filters on. I have even isolated fuel and gone from a bucket straight to the new mechanical lift pump and still nothing, what's baffling me is that I can use starter fluid to get it going and blead air from injector lines and it will idle for hours just fine. but as soon as I bring up rpms to a steady higher pace it will run for roughly 60 seconds then stall out and die and not start again. PLEASE HELP, could it be electrical somehow? Also the shutoff solenoid is working properly as well.

Could possibly be the overflow valve on the injector pump .

https://www.google.com/url?sa=...nwAUlqUylwT5bHCGowTC

My 8.3 has always started well. Normally, when I replace the fuel filters I mostly fill them with fuel. It will start and run smooth within 30 seconds. The system normally clears air promptly.

After I replaced my lift pump it would not run smooth and well. Turns out I had an air leak on the suction side. When I tightened the fittings, it ran fine again.

Be sure the fuel solenoid is pulling hard enough to open the fuel control valve fully. There are two windings: the weaker one holds the valve open, the heavier winding pulls it open and and is only energized during cranking. If the solenoid does not fully open the valve, you will only get partial fuel and reduced power.

Thank yall. Will the overflow valve work on 8.3 as well?

Yes sir . The 5.9 pump is the same as the 8.3 pump . I installed that one in my 94 Bluebird with an 8.3 . I also used a 95 Dodge Cummins mechanical fuel pickup pump on it , ran great .

Replaced and still having same exact problem. Not sure whats going on. Any other advice?

Are you positive that the fuel shutoff is working properly . It has two positive wires . One only has power when starting , then the other one keeps it open while running .

Also fuel pressure to the injector pump needs to be at least 30 psi .

Other than that I would think it would have to be an internal problem with the injector pump . I'll research it and see if I can come up with anything . If you have an injector pump specialist in your area they might can shed light on it .

https://youtu.be/6rNawg7pTgw?si=rMvThUmvmk1YfTH4

Yes fuel shutoff is working properly and staying open when running and there is pressure to pump as well.

It could be that the rack inside the injector pump is stuck . Here is a discussion about that .

https://www.google.com/url?sa=...ypI987BO9Cw6Sb4VG8Ju

With the low sulfur diesel and our older diesel engines with mechanical pumps it is important to add a lubricant.

I use this one :

https://www.googleadservices.c...g8oAHoECBIQSg&adurl=

Ouch! Parked the Barth here at home. Was going to take it for a drive and would not start. Finally gave up an put the eletric pump used in the dodge pickup in the late 80s. Works great now. Almost starts on first revolution.