shut down

[Ricktinfwb]

'95 6.5Turbo(K1500)... new rebuilt engine 47000 ago.rebuilt inj. pump, new turbo, new vaccum pump, new PMD (gray Stanadyne w/#7 resistor) new lift pump, cleaned fuel tank 1 yr ago; relaced PMD less than a yr ago, starts, runs GREAT...BUT now after being shut down for 20-30 min. it re-starts perfectly and idles for 5-10 seconds and shuts down....un-commanded....restarts and runs perfectly after about 4-5 cranking efforts. Sounds like fuel to me...but if anyone has suggestions, I could use them!!! Love my truck...but it is about to go the way of my last wife!!!!(also a new oil press switch)

[vsandme]

im fairly new to diesels, but have you cracked open the valve to see if fuel is steady coming out? and hows the fuel filter/s?

[Ricktinfwb]

im fairly new to diesels, but have you cracked open the valve to see if fuel is steady coming out? and hows the fuel filter/s?


Steady stream of clean fuel when I 'sump' the filter....also a new oil press switch(which controls the lift pump) thanks......

[Ricktinfwb]

After eplacing the oil pressure transmitter..AGAIN...fuel pump relay AGAIN..I've determined that there is either a wiring issue(yes, I've cleaned all accessible cannon plugs) or an ECM issue. The lift pump worked normally when the relay was 'jumped' directly, but WAS NOT pumping under normal conditions.
I now have a switch, wired to control the lift pump..works beautifully.

[JohnC]

The ECM has nothing to do with the lift pump on a '95. When the starter is energized the relay is energized and the lift pump is powered through the normally open contacts on the relay. When the engine has oil pressure and the starter is not engaged, power flows through the oil pressure switch and the normally closed contacts in the relay. IIRC, if you put the shifter in D and turn the ignition key to start the pump should run. ('95 only.)

The manual switch is not legal for use on the road, and isn't really safe, as when a fire burns through the fuel line the pump will continue to run.

If the oil pressure switch fixed it before, it will probably fix it again. Get a Delco switch for the longest life, and install another relay to off load the switch for essentially unlimited life.