Hard Starting when warm

[T.C.Mac]

no excessive smoke when it does finally fire, checking the glow plugs with a infrared thermometer the glow plug is 660 degrees f stone cold. after the 15 minute cool down the controler only stays on long enough to bring the glow plugs to approx 440 degrees F?
doesn't seem to be any fuel in the oil?

[HUMTECH]

Any codes set? tough one to diagnose over the internet. As far as the glow plugs not coming on as long they are set on a timer and will come on for shorter periods of time with a warm engine. Possible leak in the fuel return system and after it sits the air bleeds out? You can always put a piece of clear hose in place of the return line at the pump and check for air bubbles while the engine is running.

[Yetti]

if it helps the lead going to each bank from the controler should pull 55 amps. each plug pulls around 15 by it self. if your having issue with plugs its one thing, but your discribing a pump issue. under the right conditions the check valve on the pump can pick up debrie. problem is the debrie is coming from the innereds of the pump. if the check valve is leaking then it will loose its prime by drawing air back into the pump from the over flow line. the valve screws right into the top of the pump and looks like a brass nipple with a small hose attached. if the pump goes real bad it can and will over advance the pump timing. once the head presure reachs 10 psi it will quit starting. if you suspect the pump/valve after all is said and done remove it and put in a straight fitting with no check valve. if it fires and runs the pump is going bad and will need rebuilt.

[T.C.Mac]

OK GUYS, THANKS FOR ALL THE INPUT ALL GREAT IDEAS, BUT I FOUND IT... GLOW PLUG CIRCUT A OK, FUEL DELIVERY A OK.. INJECTION PUMP A OK....
THE PROBLEM WAS WHEN THE VEHICLE GOT TO 160 DEGREES OR HOTTER THE STARTER MOTOR WOULD DRAG, LOSE ABOUT 100 RPM BUT STILL CONTINUE TO CRANK. IT JUST WASN'T CRANKING QUITE FAST ENOUGH TO CATCH. TOOK MY STARTER IN TO A REBUILDER AND $450.00 LATER IT FIRES FIRST TIME EVERY TIME.
SO YOU GUYS KNOW, IT DIDN'T "SOUND" LIKE THE STARTER WAS ANY SLOWER SO BE WARY...
THANKS AGAIN FOR ALL YOUR INPUT
T.C. MAC...