My 1999 dodge 5.9 is missing bad. It has a Mad Dog 100 lift pump. I don't have a pressure gage. It acts like it is starving for fuel. Money is tight right now so don't want to replace something that is not the problem. I am questioning the lift pump. Is there any way of checking it without a pressure gage? I unpluged the pump and it acted the same way with it pluged in or unpluged. Any help you all can give me will be appreciated. Thanks

 

Wait, are you saying you unplugged the lift pump and ran the truck without a lift pump at all?

If you weren't running low fuel pressure before, you sure did then...

 

Yeah if you unplugged your pump you are damaging the VP. The only way to properly check the lift pump on the truck is to have a pressure gauge. The more you run it with out the lift pump the faster you will end up replacing a $1000 VP.

 

Thanks. I am going to get a pressure gage today. Last night I got under thr truck and had my wife turn the key on. Then I had her turn it off and back on bumping the starter. I could not hear anything or feel anything from the pump.