Engine/Transmission (1998.5 - 2002) Fuel Pressure Questions

[LCampbell]

The lift pump has been relocated to the fuel tank & then the VP44 was replaced after 2 successive 0916 codes. After recently installing a Westach fuel pressure gauge & then taking the truck on a short trip I am seeing the following fuel pressures. 7 1/2 psi at idle, 5 psi at 60mph on a level road & about 2-3 psi at 70 mph & about 2200rpm up a long uphill grade while pulling a small enclosed trailer with about a 2500# load. I would be afraid to try WOT because it would probably suck the fuel pressure down to zero. The truck is stock & out of warranty. From what I have been reading on this sight it sounds like these pressures are low.

Any Suggestions????

When I questioned the dealer about the fuel pressure a while back they said that the pump is putting out the proper flow.

Thanks in advance for any help provided.

 

[Sixpack]

Same pressures here before I made a couple changes. First I upgraded my fuel lines to 8-an and second I added a Carter 4600 7psi pump where the stock lift pump used to be. Pressure now is 15psi at idle and 12psi at WOT. If this 4600 pump doesn't last longer than the other POS pumps then I'll do the Walbro setup. I just had to try this first. Phil

 

[AFarmer]

Look into getting a FASS system. To get the most HP and reliability out of your VP you won't need to let that pressure get below a bare minimum of 10lbs.

 

[LCampbell]

Thanks for the replys. I would like to hear from someone who has the same intank lift pump setup & what specifically they have done to resolve the low fuel pressure problems. I assume that I am going to have to remove the tank to pull the pump in order to install an aftermarket system. What about a big line kit?

 

[mhenon]

Thanks for the replys. I would like to hear from someone who has the same intank lift pump setup & what specifically they have done to resolve the low fuel pressure problems. I assume that I am going to have to remove the tank to pull the pump in order to install an aftermarket system. What about a big line kit?

I have the in-tank pump and, like you, am not happy with it. I just added the Carter pump down by the frame and let the in-tank act as a pusher.

This and Vulcan Big lines brought my pressure up to 20+ psi.

Mike

 

[mhenon]

One thing I should have added. The Carter LP runs very quiet with the in-tank supplying a head of pressure. If i turn the in-tank off (toggle switch in the cab) the Carter still supplies about 12psi but it's loud... like it's cavitating. Doesn't sound good at all.

Wonder if this is why they're going belly up so fast in the stock configuration?

Another thing I'm going to change is the OEM wiring to the Carter. Just getting real suspicious of the voltage supply coming from the ECU under hard conditions (like the LP's cavitating!). A relay in there should take care of the load and put a solid voltage to the pump.

Mike

 

[JMcKee]

In tank setup

I reciently had the in tank setup installed under warranty after the stock lp on the firewall gave out. Gauge reads 7-10 psi at idle, 5 cruising down the freeway at 60, and zero at wot most of the time especially when the box is cranked up. Crappy setup but warranty none the less. What is involved with removing the in tank pump after warranty is expired and installing a more reliable fuel delivery system?



thanks

joe



2002 4x4 extended cab short bed,muffler gone,silencer ring gone,bhaf,isspro fuel/exhaust/boost,edge drag comp,leveling kit,305 muds,smarty soon.