OK I decided to tackle the problem myself. I took the check valve off the IP again and found it was clogged. Put the T back on the return line and left it off the IP. The generator ran fine without shutting down. I figured the system got flushed out since i left the top of the IP return line port open. Reassembled the T and check valve (after cleaning the check valve) and reconnected the return fuel lines. The generator ran for 7 minutes and then did the slow down/shut down routine.
Took it apart again and found it clogged. Decided to run the generator with the port open again to flush the debris. Same thing again!
I decided to separate the IP return line from the injector return line and eliminate the check valve.
Since the fuel tank has multiple return ports I disconnected the one for the exterior fuel feed. I installed a compression L on top of the IP and ran a copper 1/4" line from it. I inserted the 1/4" copper tubing into a 1/4" air hose and clamped it. I put a barbed fitting at the other end of the hose and inserted it into the return port hose.
I reinstalled the T with the check valve still attached to the return fuel line. I restarted the engine and watched the IP. The check valves leaks a little but I have a pan under it. I ran the engine like that for 30 minutes without any problems.
No the question is: How do i clean out the IP so it stops clogging the check valve? I would like to reattach the line like original once the debris issue is resolved. I was hoping someone could tell me a procedure for cleaning the IP (for beginners) without risking damage to the IP.
Any other suggestions are welcome.