Hard hot start

[mikediesel]

I know from looking over the net, and exploring the site this could be many things, but I really need help with this. My 2001 Dodge 2500 starts perfectly when cold. The truck is hard to start AFTER it is brought up to normal operating temperature and attempt to restart after shutdown. It cranks for a bit, finally turns over, and then blows a bit of black smoke and runs perfectly.It does have the relay installed that shuts off power to the VP44 while cranking (this fixed the hard starting I experienced before). I have replaced this relay to make sure that this is not the reason for the problem now. I replaced the lift pump two years ago. It is a FASS DDRP2. I have a dash mounted fuel pressure gauge that is showing good pressure, at idle and WOTI took it to the dealer, wanting to get a reflash. They said that there was no reflash available for my truck. They told me that I would have to wait because their best diesel mechanic was busy that day. I said no problem, I want the best. They call and tell me the stock lift pump needed to be replaced with one that goes in the tank. They couldn’t believe that the original lift pump was still in the truck! (I started thinking there was another pump I hadn’t replaced!) Then we go out to the truck, and I couldn’t believe that they were looking at the FASS pump with me, (we both saw the FASS stickers on the pump) and they were telling me it was the Original PUMP! Needless to say I picked up the truck and now need your help in figuring out how to fix this. Sorry for the long post. Thanks.

[dripley]

i am curious as to what pressures you are running. 17 to 20 at idle and 14 to 17 at wot are good numbers.the dealer did build any confidence with the analysis of the lift pump being oe. what ever you do dont let them or any one else install the in tank pump it is worse than the oe. i just got thru replacing mine with an air dog. i will have to defer ot some more knowlegable folks for your hard starting problem. they cant be far behind me.

[mikediesel]

Thanks.Yes, I now have no confidence in the dealership being able to help. My fuel pressures are 19 at idle and 16 at WOT. I had someone local tell me the in tank was bad too. Apparently that's all Dodge does now - the in tank solution. I've been really happy with the DDRP 2, it keeps good pressure and was pretty easy to install. Heard all these stories about folks replacing multiple items and still having problems, so I don't want to do the same.

[dripley]

your pressures are good. your opinion of the dealer is good. i dont know much about the DDRP or the hard starting while hot other than what i have read here. instead of me leading you down the wrong road lets see what the other folks have to say. i have not had to deal with that problem.

[KATOOM]

Do you still have the original VP? If so then next time you experience the hard hot start issue, stop cranking, open the hood and pour about a gallon of cool water directly on top of the VP's computer. Of course this means you have to carry around some water with you which could be an inconvenience.What I'm getting at is that since you've already installed the delay relay to stop the fuel pump during engine cranking that the original VP's computer is showing signs of being overly hot for many years and has racked up its fair share or heat cycles during that time. So then what happens is the computer gets hot and begins to intermittently short out and cause many other issues as well as the hard hot start. Pouring the cool water directly on it will cool it enough to allow starting but if this works then just know that it wont be long before it fails completely. And when it fails, it can fail at any time, even while driving.

[mikediesel]

Yes, I do have the original VP44 (as far a I know) - I bought the truck with 93K and it now has 147K. I will try the water test, the next time it won't start when hoe and will post results - thanks. I replaced the fuel pressure sender, and FP is 20-21 at idle, and even delaying shifts at WOT, I cannot get it to drop below 10 PSI. This part seems good doesn't it? I really don't want to go here, but if it is a VP, where is the best place to get one, and how difficult is it to install. I'm pretty handy and easily replace components - is there timing involved?

[dripley]

10 psi at wot is low. in an earlier post you said you had 16 at wot. could be a sign of your ddrp is crapping out. i dont know what if anything that would contribute to a hot hard start problem.

[MarbleCrusher]

I think what he was trying to say is that fuel pressure doesnt drop below 10psi even at WOT throttle, since thats the most common number people are told i think he was just saying that to rule out a fuel pressure problem.-Jordan-

[mikediesel]

Yes, the earlier 16 pressure was at WOT, without delaying the shifts. The 16 PSI was WOT under normal driving, the 10PSI was when I held it in the lower gear much, much longer than normal. It was to rule out a pressure problem. Is 10 PSI bad under those conditions. I have no mods on the truck, just the DDRP2, and an MBRP exhaust.

[dripley]

i know 10psi is low.but from what you are saying its probably ok since under normal circumstances you would not see 10psi. mine stays right at 16.5 at wot even above 3k rpm. mine does not see that very often, only when the teenager in me comes out. if you see that pressure constantly it would be a problem. the overflow on the vp doesnt fully open till around 14 psi and thats where you get all of your cooling from.

[mikediesel]

16.5 PSI steady, what type of lift pump do you run?

[MarbleCrusher]

looks like hes showing and Airdog II 165 in his signature-Jordan-

[Mopar1973Man]

The reason why the dealer was tell you to put a intank pump in is because the fact no pump is designed to suck fuel any length of distance. So most of use have move the lift pump back close to the fuel tank reducing the suction required (lift).But I would look into pump relocation kit (Vulcan Performance) and move the FASS back by the fuel tank with all 1/2" lines...

[dripley]

16.5 PSI steady, what type of lift pump do you run?

it is an AD165 and it is overkill for my truck. the pressure on it is adjustable. the raptor is adjustable also and i believe youcan get the same pressure out of it. The AD will pump more gph than the raptor. another reason iwent with the AD165 is it came with a kit to eliminate the in tank pump dodge gave me a few years ago. the in tank pump is a pos. the pressure was lousy and i ended up putting a booster pump on the frame rail to help it. the in tank pump cost $1000 and the booster pump cost around $300 plus my time. i did not know anything about the fuel system in these truck then and just went along with the dealer. the AD cost me $630 and my time to install, a cheaper product that works right for the truck.

[burnt_servo]

for the last year and a half i have been driving my truck like that . ( 2001 , automatic , fas 150 lift pump ) hard to start when warm , eventually really poor mileage , various engine codes .... code 216 was consistant . when i replaced the pump a couple weeks ago had code 1689 come up . and the truck had next to no power , got around 4 mpg and still hard to start . check your codes and see what come up . if i recall corectly the hard starting when warm is a indication of computer problems on the pump .there is suposed to be a power transister that has a poor conection to the main board that gets worse over time . i haven't pulled my old pump apart yet to confirm this , but i have seen pictures in other forums dealing with european pumps similar to the vp44 hope this helps some

[mikediesel]

Thanks for all the info. It's not showing any codes, and I drove it all day last weekend start stop. weather was cooler (85-90), and I parked down hill each time - started perfectly. Will have to try it not parking downhill. The relocation kit sounds like a good idea too. From all that has been said, I guess it most likely is the computer on the IP, but if I can get a year out of it (or close) I'll be able to save up for it.