Starts right up, runs rough, dies

[hce]

Was running just fine, let it sit for a couple weeks and starts acting up. Fires right off, run fine then gets rough and dies, about 20-30 seconds. Have to crank a bit to get to re-prime, runs fine once started again. Scenario will repeat if let sit for a couple of hours. If shut down for a minute, it will start fine, but then idles rough and stays running. O-rings are fine, no other visable leaks present. Tried a electric pump inline and no change, same on both tanks. I have had o-ring leak, but they took much longer then this to affect starting. Really perplexed by how fast it loosing prime and do not like working my starter this much. Maybe the moose is getting tired.

 

[The_Josh_Bear]

Do you still have the factory return line off the filter header? If so your check valve inside the fitting on the header is broken. Quick fix is remove the hose and plug, better fix is to replace the check valve with a better one.

Like this but not 10mm:
https://www.google.com/url?sa=t&sou...FjAAegQIChAB&usg=AOvVaw21mvSj0su35o2K3n7Ta5ZQ

 

[hce]

Found it. Let the electric fuel pump run for a while. Little leak out of the old water separator drain tube. Cranked the shut off valve on the bottom, all problems solved. Time for new orings in water separator again. Electric pump might be a good tool for air intrusion, as long as it is right off the tank or tank switcher valve. Possibly could restrict the return line to cause more pressure to find leaks quicker.

 

[lotzagoodstuff]

Nice catch! Great diagnosis technique. I have a Facet pump in my toolbox for transferring fluids, but this shows it's worthwhile having one for this type of trouble shooting.

Treat yourself to a cold beverage as a reward

 

[hce]

Follow up. I will say my comment on running fine in the first post was correct. Fine not great, white smoke on initial engine start up and cold acceleration haze is gone Very little black smoke either the banks/precision turbo balances out the moose pump well once again. Just more and smoother power everywhere. Funny how these engines can slowly descend to a lesser state of tune and not be noticeable how far the descent was till brought back up to par. Honestly from the white smoke thought I had a weak injector.

 

[Jim993]

I took the water separator off mine in 1999. I do check the fuel filter for water when I change it every 15,000 miles. No water so far.