'99 hard to start

[MCain]

After I have driven our '99 3500, it does not start immediately. Fuel pressure is 8 psi at full load. When I turn the key to the on position, the fuel pressure does not come up before cranking the engine. Once it starts, the fuel pressure comes up to about 12 psi. What (pressure switch?) and where is the component that controls the lift pump? I presume I should always see fuel pressure before starting the engine? The mechanical gage is connected to one of the 1/8 NPT ports on the filter housing. Thanks!

 

[HBarlow]

I'm not a mechanic so could be mistaken but I would expect fuel pressure in the line between lift/transfer pump and injection pump. If it is not present when the key is turned on I would suspect the lift pump itself. If it is failed or failing it can and probably will still run with the injection pump sucking fuel but the injection pump is likely to fail if it continues.

The lift pump is only about $150 from a Cummins dealer and if you have basic skills, not too difficult to replace yourself.

 

[DavidC]

What your seeing is normal When you turn on the key it is a very quick blip to the pump and not really noticeable. If you momentarily crank the engine the lift pump should run for 20-30 seconds. Your pressure sounds close to normal for the stock lift pump.



Dave

 

[MCain]

Thank you both for your time. I am new to the TDR website and later found discussions about air leaking into the fuel line. I had to replace the starter, so I removed the lift pump and fuel filter housing to get to one fastener on the starter. I found the leak. The banjo connection on the lift pump discharge port was loose, which pulled air into the fuel system. It now starts like a brand new truck!!