I'm having a similar no start issue. If I fill the fuel filter up with diesel, it fires right up though. Any thoughts?

 

Jim,

I extracted your post and created your own thread, it can be confusing when mixing problems belonging to more than one person.

You should also tell us the year, model, engine size, etc. etc. etc. so people have something to work with.

 

OK. Thanks.

1985 F250 6.9l diesel

200k

Injection pump and fuel lines replaced 5 or 6 years ago

Driven 1-4 times per month locally for dump runs and gravel pick up etc.

Recently the truck would die at idle and was having a very hard time starting. I had to keep my foot on the accelerator to keep it running at stop signs. I picked up a fuel filter, filled it with diesel installed it and it fired right up, not problem. I let it idle for a while then I shut it off. Went out next day and it would not start.

I've since taken it to a diesel mechanic. He says it needs an injection pump(again?). That is a very profitable solution for him.

Any ideas?

 

Make sure the pump down on the driver's side front of the engine is working ok. It's what pulls the fuel from the fuel tanks and sends it up to the fuel filter. I believe it should have around 5 or 6 psi coming out of it.

 

Those injection pumps should go 100,000 miles or more before needing a rebuild, so I'd be surprised if that's the problem. I'm with Franklin. Check your fuel pump.

 

Sounds like it's sucking air. check the o rings on the return lines at the top of your injectors.

 

X2 on that. Sounds like once you get it primed is ok, until it gets more air in there.

 

Concur! Also check the rubber portions of the supply hose, from the top of the fuel tank, to the engine. Anywhere there's a rubber section, there's a potential problem. Metal portions should also be looked at.
Cracks in the line can let air in, without letting fuel out. Air is thinner and smaller than fuel.

If it still has the water separator on it, these are prone to causing issues.

 

looking at the diagram for that system again...it seems obvious that the injection pump is not getting fuel.

Like Dave said...I would check the fuel pump first. Or make sure it's not sucking air.

If you fill the filter and it starts and runs...then it would seem to me the injector pump is working, or it wouldn't run at all.

 

Thanks for all of the tips. Here is what I did and what it's doing now-

Pulled fuel filter. It was full of fuel.
Emptied fuel out of filter and filled half way with Marvel's Mystery Oil and half fuel
Emptied rest of Marvel's Mystery into the tank, and added a jug of diesel cleaner/stabilizer as well
Turned the engine over with foot on pedal a little, nothing and then it fired and idled fine
Hopped in to drive away, pressed the throttle and RPM's would not come up, then it suddenly lunged and drove away
Drove on the freeway for about 20 minutes, it drove fine, seemed a little peppier
It has trouble going from throttle to idle, if I am driving and let off the pedal it dies, if I let the pedal back slowly it does not die, it starts right back up with some pressure on the pedal, if I don't give it throttle when I start it, it fires right up then dies, if started with some throttle or let down slowly while driving it will idle just fine
The exhaust had been pretty black for a long time, it is now not black unless I put the pedal to the floor, the exhaust is maybe a little blue if anything

So it drives great, just has trouble with the idle from speed or from first firing up

Any new suggestions with this information? Thanks for the help.

 

Blue, or white? white is raw fuel, black is burnt fuel, blue is oil.

My bet is still on sucking air, by putting oil in the filter, you cleaned the injectors, but did nothing towards the original problem.

The rubber hoses and rings came with your truck, and have hardened and dry rotted.
Have you ever replaced the fan belts? I'm sure you have, because they would have worn out by now. Same thing.

NAPA sells a kit to do the return o-rings and hoses, I think the price is reasonable.

 

The throttle problem doesn't sound good to me. I am leaning toward the injection pump myself now.

The leaking o-ring/air intrusion only causes starting problems after it sits awhile. I have had the lift pump suck air from a hole in the fuel line going to the tank, but that caused surging when going down the road.

 

Take the filter off and fill it full of power service brand Diesel Kleen. Start the truck run it for 15sec then shut it down and leave it sit over night. Next moring fire it up and drive it like you stole it. It sounds to me like the pump is sticking when you let off the throttle. I highly doubt you need a new pump, the one you have is just in need of a good cleaning.

 

Thanks for all of the help. I think you guys saved me from writing a $1200 check to the repair shop. I ran straight Diesel Kleen for 30 seconds, shut her down over night, fired it up the next morning and drove it hard. Problem solved. Starts and idles fine now.

I have a new problem though. There is diesel leaking from the lines around the lift pump. I tried tightening the clamps, but it is still dripping. These lines were not leaking before I took it into the shop. I am going to replace the rubber lines on and around the lift pump. I've never done this work myself on a diesel, so I am unsure of the process. I've never bled the system either. There is a shrader valve on the filter housing. Any tips?

 

The lift pump and it's lines are no different than a gasoline engine. Do what you need to do, and then start the engine. As long as the fuel filter stays full, you should not have any problems getting it started and running. Most of the air will make it's way down the return system to the tank.