I have the '03 4.7L V8 Ram and I've been having some odd issues with it. It will start fine but during my commute I notice the RPM's will fluctuate, for instance at a red light it will ocassionally drop between 250-1k RPM and the odd time it will stall right there. Also, it has also stalled while driving, the other issue is getting it to start afterwards. I can hear the starter working and most times it starts the first try after stalling, other times it will take 10-20 minutes of letting it sit before getting it to start again. I took it to a local mechanic to get diagnostics. He didn't give me specific code numbers but was able to tell me it could be the purge solenoid and that there was a 'small-gross leak.' I went ahead and changed the purge solenoid but still having the same issue. Any ideas here of what my problem is?

 

EGR valve most likely. Easy fix and not too expensive. Its located on the top back of the motor right behind the air intake. 2 bolts and a plug. Make sure the gasket is sealed.

 

It could also be the fuel pump gettin weak. If it dont wanna start try hitting against the fuel tank about 2/3s back. Alot of times that will get it going again.