I've got an interesting problem that just started on a recent trip. The vehicle is a little motorhome built on a Ram 3500 van, 5.9L motor. When starting the motor cold, it fires up instantly and runs for maybe half a second, then dies. It does this repeatedly for maybe 5 or 6 times, then on the next try it stays running. When warm it usually does not have this problem, but occasionally it does. This just started out of the blue. Otherwise it runs perfectly.

Anyone have an idea?

 

I forgot to mention that the van is a 2003 model.

 

By cold and warm do you mean the outside temperature or engine temperature?

 

Engine temperature.

 

Actually, I don't really think it is the engine temperature. Once the engine has started and is running continuously, even for only a minute, it then restarts without a problem. A couple of hours after shutting down, it still starts immediately. The next day, though, the starting problem reappears.

Like I said, weird.

 

It could be a bad check valve in the fuel pump assembly. I would connect a fuel pressure gauge and then let it sit overnight with the FP gauge connected. Then check to see if there's still pressure in the morning. If not, the check valve is slowly leaking and the hard starting/stalling is because the pump has to get the fuel line filled back up before any fuel gets to the engine.

 

Good suggestion, thanks. I was thinking along those same lines, but I didn't know enough about it to judge if it was reasonable.

 

Mine did this early this week. We had plenty of rain and it was cold. I changed the cap-n-rotor and the problem went away.