Engine/Transmission (1998.5 - 2002) Need Advice on Low Fuel Pressure

[MGomez]

I had my engine rebuilt roughly 7,000 miles ago while the engine was out I had a new Lift Pump installed and Water pump as well. I wanted some more power and had a Edge with Attitude Module installed and it works great. I never had a fuel pressure gauge before now that I have the Edge Module the truck starts and idles at 12 to 13 psi as it warms up it drops to 5, 4, 3 psi I shut the engine down and restart it and the same thing 12 to 13 psi after it runs for 3 to 4 minutes it drops I changed the fuel filter thinking it might be dirty and had no change. Can someone help me with this matter will the FASS Fuel Pump Take Care of This?



Thanks in Advance



M. Gomez

 

[jhoughton]

I don't know what year your truck is but I had a similar problem to yours. Mine was actually sucking air somewhere between the tank and the recocated lift pump. I was able to determine it was where the factory line connected to the top of the fuel tank. I installed a Draw straw mod and now with the same lift pump have 13 idle and 11 WOT. I also put on another lift pump about 4k earlier for this problem. At least I still have it I doubt that there is anything wrong with it. I would highly recommend relocating your pump if you have not done so already. It's all available through Vulcan. When I relocated I picked up 2 psi with the same pump in new location. I also went to 1/2" lines throughout. Very pleased with all. Hope this gives you some other ideas. Jim

 

[MGomez]

I have 1998 24V with the 5Speed Transmission 127,000 miles I lost number 5 cylinder that's why I had the engine rebuilt at 120,000. I never knew what kind of fuel pressure it had. Reading about the problems with the lift pumps everyone seems to be having I had it replaced now I'm afraid to drive my truck.

Thanks

M. Gomez

 

[GCULP]

check all the lines to the guage, I just changed 3 lift pumps only to find it was the silly little fitting on the isolater bleeding off pressure.

 

[KBrasch]

Just installed my juice w/att and am having the same exact problem. 14-15psi at start up and then down to 3-4-5 instantly no matter what I do. Going to check with a manual gauge and check over my lines tommarow. Keep us posted on your fix, i'll let you know if I figure mine out.

 

[KBrasch]

Yep it was the lift pump. Luckly a local shop had one ($123) with one year war. Took about 45min to swap this morning and all is good again. 15-16psi idle, 12-13wot. Hope you get yours figured out. Kyle

 

[MGomez]

Good to hear something Positive, I've ordered a Fuel Pump relocation Bkit and Big like Kit, I guess I'll be replacing the Fuel pump as well. I'll let you guys know as soon as I get them and install them.



Thanks Everyone for your Help I'll be in touch



M Gomez

 

[MGomez]

Well I got my Big line kit in from Genos Garage an d installed it Saturday night my starts at 13 psi idling as I take off it will drop to 12 and under WOT it drops between 11 and 10 psi. Going down the freeway it's steady 12 and lots of power I didn't have to change the Lift Pump since it was new. Many thanks guys greatly appreciate all your advice. This is what makes having a web site like the TDR a GREAT PLACE you can get help, advice, and save a lot of money with everyones help.



Thanks Again Gary and Kyle



Marga

 

[JHatch]

glad to hear the big line kit works just got mine in the mail from geno's I had put stage 3 injectors and installed a 3 psi light. on start up after the install the light would start flickering at 1200 rpm then go on steady at 1500 got a bus campaign pump and installed worked good no light for 30 mi then the light at1800 now getting gradually worse checked with a gauge and it is acurate. dont dare drive till i get the big line relo kit on and the westach gauge i also ordered installed , hopfully this will fix mine to, really want to test those injectors out.

 

[Fishin Guide]

The Vulcan Draw Straw and Big Dog fuel line kit brought my WOT pressures from 22psi to 37psi.



Of course I am running a 12V mechanical pump as well.



Dave