The OPS has 2 circuits,one for the gauge and 1 for the LP.

The LP circuit burns out because it was under built so that is the reason for the OPS relay mod.
Once you replace the OPS with an AC Delco OPS and do the OPS relay mod you will likely never need another OPS again.

Kennedy Diesel also sells an OPS relay mod kit if DIY is not for you.

 

Try some more diagnostics 1st Lift Pumps & OPS operation and troubleshooting

 

ok im leaking fule out of bellhouseing where is it comeing from??

 

There are 3 fuel lines connected to the filter manager housing and 3 O-rings contained within it-all can cause fuel to drain from the bell housing.

The water in fuel drain hose that goes forward under the intake to the T-valve can leak.
The IP feed line that goes under the intake can leak.
The fuel line from the LP can leak.

The fuel heater O ring can leak and often causes hard starts after the truck sits.
The water in fuel sensor O ring can leak causing the same problem.

The filter O ring can also be a problem-the original style filters can only be installed 1 way,they clock into the filter housing on the teeth of the housing.
If not properly installed you will get a leak because it won't tighten down.

The newer integral filter/cap style do not have this problem but several people have reported trouble getting them to seal properly.