7.3 idi air in lines

[Harrison jeffords]

92 7.3 idi. I found air in the lines but it only happens intermittently. The truck will run really crappy and almost have a surge and I’ll pop the hood and I can see bubbles in my clear line. Then after about 10 seconds it will return to normal idle, then clear up and have no bubbles in about 30 seconds. Or it will die all together and not start up for about 30 minutes to an hour after it’s been sitting and it will be hard to get it started. What could be my problem here? Lifter pump? Injection pump? What are the most common places for leaks? And I forgot to mention that it can/will happen about 1 or 2 times a day if I’m driving a lot even more. Thanks!

 

[genscripter]

Trace back your lines back to the tank. Look for seepage or leaks. That is your best bet.

If the lines and selector valve look dry, then you might need to get a mirror and check the bibs on the tank fuel pickup. If those have seepage, then you might have a tiny pinhole leak on the metal hookups.

If the tank sender and lines look dry, then check the connections on your lift pump. Maybe they are loose.

 

[nostrokes]

Check all you're connections for wetness. Is there fuel in you're oil? You could have a leak on the lift pump.

The start/die/no start for half to an hour is weird if the truck is cold. Usually will start right up after a few cranks if there is air in the lines. If it was hot and doing that I'd suspect the IP going south.

 

[MtnHaul]

Is your fuel filter fresh? A clogged or nearly clogged fuel filter should cause the lift pump to create more vacuum and possibly suck air in. You still probably have a weak or failed fuel system component but increased vacuum ought to exacerbate the situation. Just a thought.

 

[franklin2]

I have also gotten pinholes in the sending unit tubing on top of the tank. Junk lays up there and rusts them out. But like the other guys said, I also had slow fuel leak from the same pinholes, running down the side of the tank.

See if this happens also when the fuel tank gets low. Your pickup tube in the tank is plastic and they like to break off. Then when the tank gets around 1/4 and you go around a turn, it sucks air.