I have a 97 1500 express van with 250,000 miles that won't start due to a bad fuel pump (according to my mechanic). I dropped the tank myself and replaced with a new unit. It started right up with the new pump but after I turned the engine off it would not start. The engine turns over fine but doesn't fire....what am I missing?

 

Swap the fuel pump relay and the starter relay. They are the same...
Your issue may not have been the pump at all.
Try having someone turn it over while you bang on the underside of the tank.....if it starts then the new pump is jammed, or defective.....

 

Thanks for the suggestions...

Swapped out the relays...engine still turned over but no fire. I also banged on the tank near the pump but still no engine fire.

 

So when you turn the key on - but before you crank it - do you hear the pump running?

 

Did you drain the tank and put on a new filter as part of the fuel pump replacement?

 

If not, I bet on seized new pump.......its under warranty at least.

 

I do hear the pump running when I turn the ignition on.

I did not change the filter or clean the tank....did I ruin the new pump?

 

test your fuel pressure

 

If the pump is running on key on then its cycling to build up pressure. If there is a blockage then not enough fuel volume will get to engine. Replace filter. You are supposed to with new pump anyway.
If the filter you take off is not clogged, ( you should be able to freely blow air through the filter...), then it could be an electrical issue at the intake.
Have you checked for codes?