My neighbor has a 110HP JD 6 cyl diesel tractor that I believe is having fueling issues. You turn on key, hear lift pump gargle fuel thru 2 fuel filters (checked for water and none present). I bled air off of both filters and lift pump stops prior to starting. Crank on engine and it will start, run for a 4 second interval and shut down. Lift pump comes back on while key is still on but engine has died. It used to do this occasionally, but would start back up and run for as long as you wanted. Today it finally will not keep running.

I have bled air to injection pump and have decent fuel flow and pressure. While bleeding injector lines, not so much fuel. My guess is that the injector pump (mechanical) is not getting fuel to the injectors. My bleed to the injectors was short lived tonite and I only spent maybe 3 minutes doing so since the tractor is in the field, it was getting dark and the battery was getting low. Anyone have any thoughts besides putting more effort into injector bleeding? I know on my Cummins it would take a good 10-15 minutes to get the air out of the injector lines before it would start.

Any input is a big welcome, and thanks for looking.

Gary

 

a start and stop thought:

1. jelled fuel/ partial block that floats

2. air bubble from first opening at injector pump.

I would hook up the truck cables to tractor battery and keep on bleeding babe! first go through from filter on up to pump and make sure no other lines are letting in air, biggest area is gasket right at filter, re seal with inspection.

good luck.

 

Once it fires keep it running with starter fluid until it catches on its own

 

I personally kind of steer away from juicing it with ether. I have a buddy that trashed his Perkins 3 cyl by using sleeping gas. He used it to start his little perk almost every time in the winter and usually hit it with 4-5 squirts. We pulled the head on it and one of the the pistons had a hole the size of a quarter in it.

 

I second no starting fluid, I always kept them running with aerosol WD40, but check to make sure it is still a flammable mix, somewhere I read they had changed the formulation. I have kept them running for over 5 minutes with that stuff before, no ill effects.

Just for giggles, could it be a oil pressure sender not giving the ECM a signal indicating pressure? 4 Seconds every time seems too consistent to be a happenstance.

 

It's been a minute since I worked for the green company, but iirc, that oil pressure sensor will shut down the fuel pump if it doesn't see high enough pressure. Or, it could be (depending on how old) a fuel pressure sensor that's not tripping the relay right. Once started the lift pump should almost constantly be going. Your comment of hearing the pump come back on after it has died leads me to believe it's not tripping and coming on soon enough after it has started to keep it going. And yes stay away from ether!!! Drugs are bad!!! I'd say check oil pressure sensor, fuel pressure sensor (if it has it) and lift pump relay.

09 CTD qcsb, parts fell off, some got added, car seat and hot wife mod w/ full wallet delete

 

Just dawned on me about the mechanical fuel pump seeming like it's weak, if I'm suspecting that I'd pull the lift pump pressure side off and let it pump into a fuel can, watch the stream, good solid stream pump doesn't shut off then I'd definitely call the injector pump being the culprit. When you bleed the lines it might be pumping up just enough fuel for 4sec of run time, but is too weak for whatever reason to keep enough fuel going to keep up

09 CTD qcsb, parts fell off, some got added, car seat and hot wife mod w/ full wallet delete

 

A friend had something like a 7800 on his lot, and a 6430 wouldn't run, did something like that. Ended up putting new fuel lines on them. Tried hitting the 6430 with ether and instantly vapor-locked it.

Can't remember how we diagnosed them.

 

Thanks for all of the input. I found the culprit. I started from the filters and bled air from anywhere I could get a wrench on the fuel line connectors. I made it to the injector pump fuel inlet. Removed the connection and pulled the line out of the inlet. At this point I noticed a rubber bushing in the nut that looked crushed. I removed it and found it torn almost in half. I replaced it with a short piece of fuel rated vacuum hose (redneck ingenuity) and tightened the nut back onto the IP inlet. Cracked all 6 of the injector lines and started bleeding. It took about 3 minutes and it started doing the rough idle run until I tightened all of the injector lines. She works like a champ. My guess is that the rubber bushing was allowing the inlet to siphon air into the line when the lift pump was not running (tractor off) but not leak fuel. It just finally got so bad with me bleeding the lines that it fed the IP a load of air.

Again thank you all!

Gary