Capt, recommend having the injectors tested. Your symptoms is a classic example of tired, worn out injectors. A scan tool monitoring the rail pressure at startup can determine the state of the injectors. Excessive return from leaking injectors doesn't allow the rail pressure to be in the correct range for proper atomization during cold starting.

Oh, and I hope you disabled the heater grid before shooting gasoline into the intake.

 

I think both you guys have 1 or more worn injectors. As the engine cranks it needs to hit a certain rail pressure before it will even attempt to fire the injectors.

If an injector is bleeding off too much fuel into the return, the engine will require lots of cranking to start, may have to be plugged in to start, or may be a no-start.

I don't think the OP's problem has anything to do with the grid heaters. A healthy 5.9 will reliably crank up in 30 degree weather without letting the grid heaters cycle.

IMHO both you guys need to measure return flow as someone posted above. It involves buying fittings to seperate the return flow of he injection pump from the return flow of the injectors. Try torquing the nuts on the fuel tubes first, but I doubt that will be it.

You idle with injector flow going into a beaker for a specified period of time, and if the flow is too high at least one injector is bad. Block one injector off with that fitting and retest. Do the math and you can calculate the return from that one injector, and from the remaining 5.

Chances are that 1 will be out of spec, and the flow for the remaining 5 will be too high- indicating at least one of them is bad. Block a different injector if you want, but for me if it has been proven that 2 of 6 are bad... Time to replace all.

 

Agreed, Injector issue. Don't skimp on them or the cheap ones will bite you.