I have a '99 Ram 2500 24V Diesel (obviously). I recently replaced the starter (unrelated) and then decided to replace the fuel filter which I had not yet done. Upon doing so, I found the fuel lift pump (transfer pump) was not functiong properly b/c it wouldn't prime the system. So, I paid the handsome sum of $270 and the truck appeared to be fine.

A few days later, my brother drove it, the first time at length since I had repaired it and we found out that the truck is very hard to start once it's been warmed up. At a cold crank, it does okay (not as good as it used to be). But when warm, it can take up to 10 or 15 5-second attempts to get it started.

I'm concerened about what the problem could be now.

I've replaced the fuel transfer pump and the fuel filter. I've run nothing but diesel in the engine. Any suggestions? I've probably run it a total of 8 hours since repairing it and would assume all of the air is out of the system.

Thanks for any help anyone might have.

Bryan