Truck Stalls and quits??

[Stamm1]

I had this happen the other day. Got to my Parents house, shut off the truck. about 30 min later fired it up. It ran about 2 sec, then died. Cranked and cranked, nothing. Took filter out poured some fuel into the bowl. It fired up. So
I replaced the filter, lift pump and relay. I thought everything was good, until tonight. Same thing, luckily I was at my buddys house, and he lives on a farm, so no problem getting diesel to pour in the bowl...
What could this be? It's like it sucking more fuel than it can supply when it starts? Could this be a OPS problem? Is the lift pump supposed to run a bit before firing, like a gas fuel pump, when you turn the key, you hear a buzz for about a second or two.
Or am I gonna have to start carrying a bottle of fuel for priming my truck?

Thanks

[94 at Large]

I will watch this thread with interest as the same is happening to me and only since the weather has turned warmer. Fortunately I have the Kennedy OPS bypass so all I do is press a button and it fills the fuel filter. It completely died the first time and wouldn't start without "priming", stumbled the second time but ran fine after about 30 seconds. My lift pump is the high output and new and fuel filter was just replaced also.

[tommac95]

>Could this be a OPS problem?

Yes, possible.
Did you drain the filter bowl , wipe out bottom when replacing , and bleed air out of cannister following filter-replacement?

If you put a gage on it that gives a clue...(hose from brass petcock on thermo mtg front engine -- lift hose and attach gage).

[Stamm1]

What should the guage read?

[Stamm1]

Well I noticed I had a fuel leak. I got further into it, the O-ring on the bottom of the filter housing is bad... But I tried the open the petcock, while its running, well the truck dies. Keep in minf I replaced the filter, pump and relay. So I hardwired the pump to 12volt to test it. Truck runs wonderful.... Idels nice, plenty of power. I tested the voltage on the lift pump, without it hooked to 12volt, it was only getting 4.5volts. Does the voltage go down with the demand for fuel? I know the pump it relayed, so doesn't that mean small voltage in 12volt constant out... Isn't that the purpose of a replay?

Thanks

[tommac95]

Hello, Stamm-
Frankly , i'm not too sharp on the '93 model year.
The low voltage feeding the LiftPump is most likely due to worn points (or insufficient closure) in the OilPressureSwitch. I'd suggest you install a new OPS , or at least check the voltage on its' input.

Replacing the OPS can be a lot of fun, if you have plenty time , patience , and the proper socket. It might be confirmative to check the resistance across the OPS before swapping out ... but the effort to break into the connector and wire up temporarily is prohibitive.