95 Chevy 6.5 td with 300,756 miles
 

A couple of questions, 1 the erg has been unhooked. How important is it and do I need to hook it back up? 2 what is the difference between marine injectors and regular injectors? 3 can I use the marine injectors without changing anything else and be alright? And number 4 after my truck has run awhile and I shut it off and let it set for 30 minutes or more it is hard to start. It will start and the die right a way and then is hard to start back. When it does start it puts out a white like smoke for 3 to 5 seconds and then clears up and runs fine. Any ideals what causes that? Thanks to everyone who reads this.

Ok the marine injectors are no benefit without the marine mechanical IP-don't believe the hype.
Standard replacement injectors with bosch,stanadyne or delphi nozzles ONLY-bosch germany preferred.
The reason being is that the IP is the bottlenkeck,stock/standard injectors can flow more fuel than the IP can supply-have them pop tested to 2200psi if you get yours rebuilt locally.

The EGR does not need to be connected-and if you get an aftermarket ECM tune done they can remove it from the programming.
The vac lines to all the solenoids still need to be in place and functioning though-the vac line to the EGR needs to be plugged.

the starting difficulty sounds like a 2 part problem-
air leaks in the fuel system accompanied by a non working lift pump?

the LP is powered by the oil pressure switch when the engine runs and it is a common failure item-replace with AC Delco only if the cause and google and install the OPS relay mod.
replace the IP fuel return line with clear diesel rated hose and with the truck safely parked and idling-watch that line for bubbles,they indicate an air leak pre LP.

You have some work to do and report back.

the LP test is with the engine running open the water in fuel Tee-valve located on the thermostat housing and if the engine stalls the LP is not working-determine why?
if it keeps running you are good as long as fuel is draining from the valve.

If it does stall you now have to bleed the system and that means the LP must work.

Lp
 

With the motor running I can open the t valve and the motor continues to run but nothing comes out of the valve. I can put it in drive with the motor not running open the t valve and turn the key to start and the fuel comes out of the t valve. Any comments

thats really curious?
It should stall when running if the LP isn't working because air gets back in.

Could be that it does need an oil pressure switch=AC Delco ONLY and OPS relay mod encouraged.

Ops
 

Can you tell me were the oil pressure switch is and is it the same as the optical sensor?

the oil pressure switch is located at the back of the engine very close to under the glow [plug relay or under the intake manifold depending if the engine has ever been swapped?

the optical sensor is a part of the injection pump and is located on top of the IP.