Archived starting problems 1997

[mglaser]

1997 2500 auto Primeloc

The truck will sometimes start and sometimes not like now, cranks fast good- batterys seems like not getting fuel.

My questions center on lift pump diagnosis, shut off solenoid diagnosis, fuel supply and return line leakage diagnosis, plugged fuel filter and screen diagnosis.

Lift pump- where is it, any pics?, how do I check for correct operation ie pressure gauge insertion point, output?

Shut off solenoid how do I test for correct operation?

Supply and return lines how do check for leakage ie vacuum leaks and are these type of leaks possible? has some one used a different type of line that has proven to be more reliable-durable?

Does the primeloc filter head port facing to the rear the place to install the pressure gauge? How can I tell if the filter is plugged?

How do I tell if the screen in the heater-screen is plugged?

Thanks for your help!

 

[LandShark]

Has the fuel return line been replaced? That's the most common cause of starting problems on 12v engines.

 

[Joe G.]

Have you tried removing the Primeloc to see if the symptoms go away? From what I have read on these forums in the last few years quite a few of those things have been tossed in the trash.



If the filter head port on the Primeloc is on the output side it would be a good place to test pressure that goes to the injection pump.



You can test the overflow valve by clamping the return hose that goes from the steel line on the overflow valve. If it starts good then there is probably something wrong with the overflow valve. Don't allow the engine to run more that just a couple seconds with that line clamped off.



You can test the fuel solenoid by tying the lever up with a tie wrap. If that cures the hard start problem them check to see if the fuel solenoid relay is working. Also check blue fuse link wire from the postitive post of the driver's side battery. If all that is good, then test the fuel solenoid by disconnecting the three wire connector to it. Apply a ground test lead to the terminal for the black wire. Apply a 12 volt test lead to the small colored wire. Then jump 12 volts to the large white wire. The fuel solenoid should pull up and hold when you remove the jumper to the white wire.



The input supply fuel hose from the tank steel line to the steel line that attaches to the lift pump may be leaking air. Replace it. The originals were junk.



You can remove the pre-filter screen from the bottom with a 17mm socket. Be careful or you may get a diesel bath. Clean the screen if it is dirty. Then remove the large screw in the middle of the fuel heater that the pre-filter attached to. That will allow you to remove the fuel heater. These things tend to crack where the electrical plug goes in. Screw the pre-filter back on without the fuel heater. Prime the system. If it starts and runs good then you have a bad fuel heater. Also check the fitting where the input line attaches to the fuel heater. It can go bad and suck air.



Check the condition of the short curved hose between the pre-filter and the lift pump.



If you have checked all the above and it still does not start and run right, remove the lift pump. Here is what it looks like:

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There are three large O rings and three check valves. If the O-rings and check valves are ok, there are no broken springs, and no metal shavings it's ok.

 

[mglaser]

What type, length, dia. hose is used for replacement of supply hose, curved hose, return hose?

 

[Joe G.]

I think the curved hose is a Cummins part. I've never had to change one. Look here for a fuel hose replacement kit:

http://www.fostertruck.com/dodge/default.htm

 

[mglaser]

Thanks Joe I think I found the problem it was the fuel seperator drain not sealing close after draining. I must make sure that the drain seals by centering pull section and pulling down at the same time.