After setting for 2 days or more I have trouble starting my 98 12 valve.The truck will start right up but after about 30 seconds will stall.It takes several cranking cycles before it will start.It runs very rough for a few seconds and then smoothes out.I will not have any more problems untill I let it set for a couple of days and then the same thing.It acts like it has air in the system and must work it out.The lift pump was replaced about 10000 mi back as was the overflow valve.Could it be a sticky or lazy fuel shut off valve?Anyone have any ideas?

 

Most likely a leaky fuel return hose. They can suck in air without leaking fuel out.
Replace it with about 2 feet of diesel rated 5/16" hose.

 

Thanks ,I'll try that.This forum is the greatest. Norm.

 

Norm, you're not going to think that after doing this job.
Although the hose replacement is straight forward the space is tight and has to be done mostly by feel, you will cuss and most likely come away with scars.

If you want to make it easier and avoid future potential problems abandon the metal lines on top of the bell housing and run hose all the way back to the tank. Takes about 12 feet but measure first.

 

Thanks for the followup Infidel.I think I'll take your advice and run the line all the way back to the tank.I do have one question about the fuel return line.Is this line down stream of the overflow valve and if so how can it suck air into the injector pump if it is a return line back to the tank? Norm

 

Think of it as the old pick up water with your finger over the end of a straw trick.
Fuel will not drain from the pump unless there is air from a leak to replace it.

 

OK that makes sense to me.I'll change the hose this weekend and let you know what happens.I'm sure your correct.Thanks again

 

I have found it is easier to get into that area with the fuel filter off - provides a little more wiggle room for the hands and forearms. Just be sure to use diesel-rated hose or you will be back at it before the scars (physically an psychologically) heal

 

Thanks for the heads up Red Ram.

 

Mine was the lift pump

 

Redrocket,the liftpump was replaced about 10k back.I'll try the return line first.I hope its not the lp;.