ICP = Injection Control Pressure.
IPR =Injection Pressure Regulator

 

Im thinking its a standpipe or dummey plug that when it cools down the seal shrinks and it begins to leak off HPO pressure it takes a longer crank to fill the HPO system back up and start

the HPO rails ontop the injectors need to come off to change those

Now its not very common to leak at the HPO rail to injector connection but

Theres an oring in the top of the injector that seals the HPO Rail to the injector its not very common for it to leak here to change those theres a little clip that needs to be pulled of the top of the Injector and then the oring fished out and a new one installed

I think if it were the STC fitting it would leak constantly and your Icp would be low number and IPR% would be High number so I dont think its the STC fitting

 

I think I read recently that there is a company that sells the injector o ring kit that includes the top o ring for the injector.

 

The Alliant Power kit has them, AP0002. I ordered them from Oregon Fuel Injection. It is a pain to replace the top injector though, you need a very good punch and some patience. I replaced all the o-rings in mine when I had them out.

Oregon Fuel Injection, diesel fuel injection pump, turbo, injector and diesel performance product specialist.

 

Thanks for all the info guys. Hopefully I'll have some time next weekend to do an air test and find out where the leak is.