Ok I've been having this issue these last few days. Sometimes when I romp on the go pedal, it runs hard and if i'm stopped it runs good until I shift into 3rd and then my FP gauge drops to 0 and my truck dies. Turn the truck off and back on and it runs fine. Same thing happened to me on the highway too. I was going about 50 and was feeling rambunctous and took her up to 80 rather quickly. As soon as I let off my FP dropped to 0 again and the truck died. Also the fuel pump WILL NOT RUN AGAIN until I shut the truck off.

Anybody else have this happen? I'm not sure if it's the truck or the ADR but I'm reluctant to recreate the circumstances if I don't have to for obvious reasons. Oh and no codes.

 

Either there is a fuel pump problem or the ECM isn't suppling a solid fuel signal for the pump. I would try un-hooking the Q'Zilla for a try... (Software issue??)

But any any case you better get the fuel issue corrected because this will kill the VP44 in the long haul...

 

yep,running a hot VP out of fuel is a bad thing.

 

Be aware gang there is a few out there that are arguing that VP44 can be ran down to 5 PSI worth of fuel pressure without harm. I don't suggest it...

How to diagnose a lift pump

Quote:

We proved on a dynomometer in 1998 that if you have 5 PSI, under load, you can make all the power available from a VP44, and 5 psi will provide plenty of return fuel for pump lubrication. We do not recommend running more than 12-15 PSI as that does NOT help the fuel system in any way. In fact higher pressures could diminish fuel delivery to the rotor and make the truck run worse at high RPM and possibly overheat and damage the fuel bypass solenoid.

Personally just because he made a few runs on the dyno for a few hours doesn't mean much to me. I look at the long haul wear on the pump. And I think I rather stick to Dodge/Cummins Specs for safety... But there was no long term testing of the pump. (100K, 200K, 500K miles ??)

 

if you have the stock lift pump then thats your problem you need more fuel.

 

several of us was having the same issue with the new com2 tune on the ADR. and custom tuning.. as soon as i hit redline the truck just poo poo'd on me. i had to turn the key off.. then the LP would not run for like 60 seconds or so. but fires right up after that. always had good FP. @ around 17 psi.

it has to do with the adr defueling up top?? dunno why. but as soon as i backed down the pump stretch it hasent happened since

 

I was wondering if that was the case. I'm also running a custom tuned version of the Comp2(the latest one) only my fuel stretch is all the way down (1200). The timing is all the way up. I've been running it like that for a while and it works like a charm( little to no smoke unless you floor it and still runs like a raped ape. a vain attempt to try and save my stock clutch ) My tps and can mins are both at 35.

On mine the lift pump will run as soon as I turn the truck off, tap the throttle to kill the turbo timer, and turn the key back on. weird huh?

 

try running the comp2 dated 11/17 seems to be a little better than the 11/24?

i'm running timing at 8
stretch at 1850
mins at 30
max at 95
timing scale 20