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Hi, the problem you have is a weak starter, the starter has to spin the engine over fast enough to turn the injection pump a minimum of 175rpm, when the starter gets worn it drags more as it gets hot, then it wont spin the engine fast enough. replace the starter with a rebuilt unit and your problems should be solved.
That is another sign the starter is bad, also you should have the batteries load tested to ake sure they are good.
Some rebuilt starters are not that good
Do you need more help?
The only other thing that I have seen is the return line is being blocked off, this happens when the rubber hoses start to degrade and the rubber inside flakes off and blocks the line. The only suggestion I can come up with is to replace the return lines and try it. It may also be a worn injection pump.
When it stalls have you checked the solenoid wire to see if it has power on it? It may be losing power for some reason.