I have a '98 w/ 12V cummins and ran with no smoke or power loss at all. Then 1 day, pulling up to stop light, engine RPM at idle was way low. At the green light, I tried to get going but could only get up to 1500 RPM in 1st gear, even with clutch in. I got it into a parking lot and it would not fire up again. I pumped the primer for a good 5 min but it never seemed to pressure up.
I got it hauled to a "repair shop" and they replaced the fuel filter and over flow valve (thanks for wasting $420). It never replicated the condition for them. I drove it 30 miles home and this morning now I have same conditions.
Is the fuel lift pump electrical and if so, where are the solenoids? Could this be a problem with turbo? I just feel it's electrical due to sudden failure with no warning. Thanks for the help.

 

If you have a 12V, then your lift pump is mechanical. Typically the symptoms of a failing mechanical pump are harder and even harder starts. Have you checked the fuel shut off solenoid? From what I've read that appears to be a more frequent problem on the 12V engines (aside from the Killer Dowel Pin). You might also have a leak somewhere, air getting into the fuel system would create a no start, die while rolling situation too.

 

i would start with the shut off solinoid first, you get the same symtoms when it gets out of adjustment, dont replace it, just adjust it... take the actuator arm off the lever, turn key on and pull actuator arm all the way up, then pull the lever all the way up, if the lever goes very far past the atuator arm it needs to be adjusted, there is an actuall measurement for it but i find this way a lot eaiser, just pull that lever all the way up and set the actuator arm to that

 

any smoke??

 

No smoke during startup tries or rough idle condition. Where is the shut off solenoid? I do get what your saying about the adjustment though, just need to find it.

 

on the left (driver) side, rear of the injection pump, the actuator has about a six inch pigtail off of it to a weather pack connector (3 wires) and is vertical

 

I think I know where it's at then. It should move up when the key is turned on, right? I ran the battery dead so it's getting charged. It didn't move last time I looked at it from off position.
Will I need to crack open the injector lines to bleed the air out of the lines? When I tried priming it, it didn't seem to get harder. Should it on a 12V when it's fully primed?
Also, where is the overflow valve? The "repair shop" replaced it but I didn't see any noticable new parts.

 

with the key on, it will not move, but if you pull up on it all the way it will stick all the way up in the run position, if it does not do that then you have a bad solinoid or wiring...
overflow valve is on the right side of the injection pump, at the top, front, and is a banjo stlle fitting.

 

Before I get home to try it, is there a way to bypass the relay? If the solenoid works manually, then I want to troubleshoot the relay. I will see if it is getting voltage during crank but don't want to short something out by running a jumper wire wrong.

 

OK, the solenoid and relay work and are set to the right position. I did find I had some fried wires at the fuel heater/pre-filter. That will need to get fixed.
I think I have an air leak somewhere though. When I loosened the line on top of fuel filter, priming it produced a bunch of bubbly fuel. Must be somewhere before the transfer pump, right?
I pulled the fuel heater and transfer pump off. Any ideas on what to test from here?