EMD-RUN8

Not really seeing this exact thing in search so I'll ask here. My '01 has a fresh lift pump that works and fresh fuel filter. Mainly when the truck is hot and then gets shut off for say 15 minutes or so; when I go to start it again it will typically take 3-5 seconds to light. Well, yesterday it took about 10 to 12 seconds on the second try before it lit.

Now, here's where it gets interesting......it's worse as the weather warms up, the humidity goes up and therefore lower atmospheric pressure. In the winter months when this started, it wasn't nearly as noticeable when it was cold or even cool, like when a cold front would blow through with high atmospheric pressure. I'm in the FL panhandle so you know winter comes and goes many times between December and April. It would improve or get worse depending on whether it was cold or warm.

I don't really smell raw fuel under the hood (other than the typical crankcase vent smell) so I'm thinking maybe its a banjo fitting, crush washer, hose or something like that. Any ideas before I really start digging around?

rebal

first double check all fittings for an air leak.if you find none then try this, when its hot and your having the hot start issue try and unplug the lift pump and then start it if it fire right up your VP is going south dont run it with out the lift pump just do this for a test

EMD-RUN8

Thanks. I'll check the fittings for sure. I'll check on the VP but I think its OK. The truck actually ran a few months over the winter with the inoperative lift pump. Had to baby the throttle to keep the pressure demand low but it seemed to run fine. But after replacing the LP, still have same problem even though the trucks cold starts much better with the new LP.

EMD-RUN8

Well, truck was a little long cranking this morning. Pulled it up the driveway and shut it off. Did a once over on fittings. Went ahead and washed off the front of the motor and down under the VP some (crankcase vent puke) thinking maybe it could have crud on the crank sensor. Washed it all off and it started like ---right now. Like a new one would. Drove it down the road, got it hot and shut it down in the driveway. Started back up with just a few seconds delay. Went to run a few errands about a half hour later and the truck started about the same way with several seconds delay. Parked at a grocery store and handled a phone call for about 5 minutes with the truck idling. Went in and when I came back--------No start. Turns over but nothing. No check engine light but a 1693 code shows up when I check. There are no other codes.

I've done a little more diggin' on the web and I'm thinking maybe the VP is RIP. Any suggestions? Gonna leave it at the store until it cools off and see if that changes anything.

Oh, by the way.....the truck has been a light duty vehicle its whole life. The heaviest thing it has ever towed is a 25 ft camper. I can't say my Pop was religious about fuel filter changes but he didn't ignore it either. I've put one lift pump in it which quit after about a year and just had another one put one about 3 months ago that works fine so far.

EMD-RUN8

Unplugged the lift pump. Truck sputters but doesn't completely fire and run. Plug the LP back in and it just turns over.

VP dead I presume?

rebal

you probably damaged the vp a while back when your lift pump was bad Its sounds like its on its last legg

mattn124

I had a similar hard hot start issue but I never had any codes.

I found this TSB: TSB 18-015-00?

here's a link to it:

http://dodgeram.info/tsb/2000/18-15-00.htm

I took my truck to the dealer and had a re-flash as per the instruction in this TSB and now My truck starts just fine when hot!

It seems as though this TSB re-programs the computer to not have the lift pump running while the starter is engaged. The only thing I don't like about it is that I no longer can bump the starter to force the Lift Pump to run for 15 seconds or so, so i am not sure how i will prime the system when i change filters...