clc900

Got a 12 valve that wont start. I think it is fuel problems but just not sure where.

I dont drive the truck much anymore and it sits in the driveway out in the sun. Last month it sat 2-3 weeks without driivng it. I had to crack an injector line and prime the fuel system because it wouldnt start. After priming the fuel system it fired right up.

Today it has been sitting about 3 weeks. Cracked #1 injector line, tried to start and didnt get any fuel. Opened the bleeder screw on top of the fuel filter and manual pumped it. Got fuel and very little if any air. To make a long story short it looks like some of the injectors are getting a small amount of fuel and some are not getting any at all.

The injector lines at the pump look like the same thing. Some are pumping what looks like a SMALL amount of fuel. Others have no fuel coming from them.

Any ideas?

Could diesel fuel get old and varnish up and plug the injector line or fuel pump?

It doesnt look like the fuel pump is pumping very much fuel. What would cause this.

I get lots of fuel coming from the fuel filter to the fuel pump when I loosen the banjo bolt on the side of the injection pump.

I cant figure out why I am not getting much fuel from the injection pump to the injectors.

Help me out if you can.

THANKS!!!

Chad

rich

what year is it had a 95 that the return line from the injector pump was rubber and was cracking and would let the fuel drain back to the tank

Crimedog

Check to see if your fuel shutoff solenoid is functioning properly. It is located on the pump and basically pulls a rod up which cuts fuel supply to the injectors, this is how the engine actually shuts off - by just cutting the fuel off. It should pull up when you turn the key to the start position, and remain up until you turn the key off. If it is not working, you can get the truck started by manually pulling the solenoid up.

clc900

Its a 1997 12 valve in a 2001 Ford F350. I had all of the lines replaced.

Crimedog....I think you may be right (hopefully). I forgot about the fuel shutoff. I will check it out and hopefully that is it. I have a spare in the shop.

Thanks!!

Chad

RCW

The fuel shutoff will not cause the pump to lose its prime. You have air infiltration.

Air gets in around the filter(s), around the O-rings on the fuel heater, around the insulation on the fuel heater connection, from bad fuel lines, and from a broken spring on the overflow valve - the little guy in the valley between the engine and injection pump where the return line connects.

All things being equal, I would bet on the overflow valve poppet spring as the culprit given the age of the truck.

Crimedog

If you are getting zero flow at the injectors, the shutoff solenoid IS a possibility (not as an air source, but as a parallel issue), and is an easy check. If it is functioing properly, check the overflow by pinching off the return line and see if that gets you any more flow, doing this will demonstrate the possibility of a bad overflow valve. RCW is correct in that the system is losing its prime, however I've never had problems starting from a dry fuel system (supply lines and injector lines) with manually priming the lift pump. I think the longest I've cranked has been about 90 seconds before it starts to fire.