I have learned a lot in the few days that I have been in this site. I own the 99 Cummins 6 spd that just quits like someone turned the key off. I wanted to install fuel pressure guages (as was suggested by someone on this site) since I have read about the lift pump problem. Are the female threads on the filter housing 1/8 NPT? Does one reflect pre fuel filter and the other one post fuel filter pressure? Could one just hook up an elec fuel pump and control it with a switch with no darn computers? I would by-pass the factory pump altogether. At least if it quits and I have the guages on there I will learn something about the problem like what it is or what its not. Thanks.

 

Yes they are 1/8 npt. One is pre filter and the other is post filter. I don't remember which one is which. You are looking for a sudden drop in pressure, so it shouldn't matter in your case. You can put aftermarket electric pumps on to eliminate the in tank pump. I would recommend leaving the 12 volt supply from the relay to keep the auto shut off factor in the loop incase of a serious accident. Your eng is computer controled, so the injection pump stays.

 

The most forward pipe plug on your fuel filter top is the port to read off of.