fuel issue lift pump?

[Robmears]

I have a 84 j code 6.2 when it runs it sounds good. But she dies and has to be reprimed to start. Thinking its the lift pump. Anyone been here befor?

[Robyn]

Sucking air is likely.

The lift pump can be going south.

That year used a regular mechanic pump, and if the thing goes away, it can cause problems.

Make sure your fuel lines are not letting air in.

A leaky hose on the suction side could be the culprit.


If the lift pump has a bad valve, same thing.


If the lift pump has not been replaced in a long time, replace it.

Install a clear hose up top on the return line, then run it and watch for bubbles.


Good luck

Missy

[joeq]

welcome to TDP.

[Robmears]

Thanks for the help missy. I put a in line electric pump. She fired right up and ran really good.

[DmaxMaverick]

Beware.....

If you use an inline electric pump, and pump fuel through the mechanical pump, a failed mechanical pump can leak fuel. The leaked fuel will either exit the weep hole and drip to the ground, or, if the weep hole is blocked or the fuel volume is too great, fill the crankcase. Having both in place is not a bad idea, as long as you have a means to bypass the mechanical pump if this should occur. Keep in mind, as long as the mechanical pump is attached to the engine, it is still trying to pump fuel any time the engine is running. If it's failed, whatever has failed will continue to fail, to the point of complete and total failure. In your case, the pump should either be replaced with new, or removed and the hole blocked (like the 6.5TD).

[Robmears]

I removed the lift pump and took out the rod. Then put the pump back on to block it off. Then I bypassed the pump with my lines. I figured an in line would be a lot easyer to get to right on the fram should anything go wrong. Seeing how my 6.2 has a plow pump on it.