6.5 td problems

94 6.5 td,
It is hard starting, it will run for about 5 sec and die. When I pull start it, it runs and starts fine. Also when i have somebody hitting the fuel
shutoff solenoid on the pump while cranking it will stay runnning. and ones it runs its ok, no problem starting hot or hesstation either.
Is has an updated pump, FSD cooler, new starter, fuel filter, 2 new optima batteries
Any sugestions?
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And now for something completely different... And take this with the knowledge that I know nothing specific about this engine. Check your oil pressure sender. Put a mechanical guage on it. Some vehicles use the oil pressure sender as a safety device to shut off the pump when it senses no oil pressure. You might have low oil pressure, or the sender switch might activate at an abnormally high pressure, delaying the activation of the pump. If the concept is similar to the gas engines, when you first turn the key to on, the pump is set to allow the first few seconds to run without oil pressure. Normally the oil pressure would build quickly, which then would continue the pump signal. If the signal is delayed for whatever reason, the engine would start and run for a few seconds.
KenG Dcc wrote:

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Thanks but I forgot to mention that the lift pump runs as soon i turn the key on. I bypassed the switch

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Ken's on the right track. There's a service bulletin on this and I used it on my '93 with the 6.5 TD. There's an updated combination oil press. switch/press. transmitter for this problem. What happens is the press. switch contacts in the switch develop high resistance and the voltage applied the electric fuel boost pump drops to about 7 volts. During crank, this circuit is bypassed, but you have lower voltage to pump then too due to excessive current draw to the starter. There's an updated part no. for the press. switch/ press. transmitter to take care of the problem. It's located at the back of the block behind the intake manifold and a little tough to get to. I had the exact same problem on my '93 and the new switch/transmitter fixed it. Ask a GM dealer to look up the service bulletin for you. It's very well written.
Garrett Fulton
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Thanks, I will check in the morning

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when was the last time you changed the fuel filter?
if you have air in to line somewhere it'll do that too.

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Bad ground guys, that was all
thanks for all the help

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Sorry, You're going to have to throw us a bigger bone than that. Details, man, details. KenG Dcc wrote:

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wrote in message Yeah. Where?
Garrett Fulton
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