Meat Man

My truck : 1998.5, 2500, 24V, auto, 4x4

I installed a 5 psi fuel pressure warning light. This might be the best money spent on my truck yet. First trip around the block turned the light on and stayed on. I thought it might be air in the fitting, changed the mounting. Light still came on, but not as much. Finally go tired of guessing, so I rigged up a gauge tonight and took a drive. I found out that the light is not lying. When the light is on, I have "0" fuel pressure. I am not using that as an expression, I mean zero on the gauge. Granted I have a 100 psi gauge that is graduated in twos, but it is still at the bottom.

When lift pump pressurizes the system (by bumping the starter) I get 10-12 psi. Holds about 10 at idle. Down to about 5 psi under WOT, but it doesn't trip the light. Light will come on when cruising at 65 mph. Not all the time, just intermittent. Check the gauge and it says 0. Pressure will not return until after I shut the truck off and restart. Also noticed for the first time tonight that when hot, the LP will not cycle when bumping the starter.

Unless someone has other suggestions, I am going to relocate LP to the frame. Might go with Big Line kit.

Nathan

Fishin2Deep4U

Make sure the lift pump is getting voltage when you are showing 0 pressure.

Call Eric at Vulcan. he's the man with the relocation and other lift pump options out there.

Dave

Meat Man

I was going to try to verify voltage last night, but I decided I liked the skin on my arms. I couldn't reach the plug when engine was hot. I am going to rig up a test connection tonight and test drive.

Thanks,

Nathan

Doug_TX

Well let me know what you find. I'm at wits end trying to get stable fuel pressure. I have a Q'zilla commander with the FP kit and it almost acts like a random number generator at times. I've damned near replaced every part in the fuel system (including the sender for the FP) to no avail. I'm thinking of selling the truck before I have to buy a VP.

ldornak

Make sure all your electrical connections are good and tight and that you have good batteries. I had similar symptoms with my FP gauge bouncing around until I replaced my batteries. Now it's stable.

DodgeCowboy

Why not go to a simple mechanical gauge? With my truck and the mods in my sig I changed out one lift pump a year ago and I am having 0 problems I have 14psi idling and no lower than 9psi pulling a load and in it hard just putting around i get 10ish pis. This is all with a factory pump in the factory spot. I am still trying to figure why

Doug_TX

Have brand new (about 4 months old anyway) batteries. All the connections are good and I've powered the pump via three different paths with no impact on the pressure readings.

I'd love to use a mechanical gauge, I just don't want to pipe fuel inside the cab.

wadecool

You need a gauge that gives you the actual FP, not a warning light. How would you know if your fp was 3or4. As expensive as the vp44 is, you wanna know the actual pressure, not just that its less than 5.

Clunk

With my cheapo mechanical gauge, there's a needle valve on the line that dampens the pressure pulses (and the injector pump creates those pulses so strong the gauge needle is a blur without the needle valve).


With the bleeder valve barely open 1/4 turn, it won't squirt much if the gauge does turns leaker.

Doug_TX

Agree the valve would be needed. But if you leaked diesel into the cab and it got into the carpet, you'd never get the odor out of it. That's why I wanted the electric gauge.

Russ Roth

Just use an isolator. Eric @ Vulcan performance has them and out of more than 200 sold he has only had 3 come back. Those were likely either operator error (don't ask how I know) or the little o-ring fell out of the bleed screw.

Doug_TX

If I have to add another gauge, what's the use of the Commander at that point? Well, I do have EGT and boost readings from it.

Meat Man

Tested voltage tonight and found that I do have power when the pump is at zero. I am going to replace LP with an Alliant replacement. I found it locally for $200. Seems to be competitivly priced with other units when shipping considered. I liked it because of the fail safe bypass.

I looked at every setup I have researched on here and could not justify going with anything much better than stock. I am not going to bomb this thing out, I have a hard enough time just keeping it on the road.

I looked at FASS, Stanadyne Fuelmanager, Holley, Delphi and BD. I liked the BD pump, but didn't know if it is $100 better without spending another $100 for relocation and Big Line kit. Would like the FASS, but not realistic for my goals. I am interested in the Stanadyne with heater and water seperator prefilter, waiting on a price and flow specs. MWFI is looking for it, but I'll still be over $350 before I'm done.

I am going to keep the light for now, but will keep mechanical test gauge handy. I agree that having mechanical gauge on all the time would be best. When I get gauges, fuel pressure is on the list. I might get it before the three gauge pod with boost, pyro, trans temp. I liked the idea of mounting it below the ashtray. I will still keep the light on there for attention grabber in emergency.

Nathan

Clunk

I'm wondering if a needle valve will help your electric gauge...which I don't have a problem with, I monitor pressures & levels with hundreds of transducers in my job.

m.rehme

My original LP gave me some crazy readings from time to time, I know it was pumping I could hear it but the check valve was letting the pressure by so it would show little or no pressure whenever it felt like it. That went on for about 50,000 miles I finally replaced the LP and pressure readings have been great ever since.
I have 313,000 on the original VP44!