January 6, 201312 yr Ok that's kinda what I thought. If I wasn't running such large injectors, would that help keep my pressures up? Cause there would t be as much fuel going into the engine, making the pressure to the vp higher?? I think that would keep the pressures up with smaller injectors. With the pressure differences you have it sounds like you don't have enough fuel flow (weak pump, too small of a supply line, dirty fuel filter, low fuel flow rate on the pump) note than an actual pressure issue. Sent from my DROID BIONIC using Tapatalk 2
January 6, 201312 yr DDRP... That's the problem... You still using the stock plumbing. I have upgraded 3/8" line from the tank to the VP. I also replace the fuel filter every 5000 miles. Someone put a small inline filter back before the DDRP. I am going to replace that and see what happens. This is why I was wondering about the bigger injectors making the pressure lower.
January 7, 201312 yr Yeah, they will cause a pressure drop and it is amplified when there is not enough volume of fuel getting to the vpSent from my DROID BIONIC using Tapatalk 2
January 13, 201312 yr Ya I am going to change that inline filter before the DDRP and see what comes of it. - - - Updated - - - So i changed the filter before the pump and it didnt really help. I didnt get out and drive it yet but it still only had 16 psi at idle. I think I posted this in another thread already, but I found out that I dont actually have the DDRP. I took a closer look and the tag says FASS HPFP. I am not sure what one but I could only guess it is the 95 gpm. What psi should these babies be running?
January 15, 201312 yr I got out and drove the truck to work today. Changing that filter did help a bit. It idles a little higher now, 16-17. It cruises at around 14, and it only drops to 11-12 at WOT. Its some improvement but still a bit low I think. I am going to change the stock filter next and see what happens then.
January 25, 201312 yr Owner Even with the cold weather as of the last week I was seeing a drop in pressure which is totally normal. I would see roughly 17-18 at idle for fuel pressure and then 15-16 at wide open throttle. But usually once the fuel warm up some it would rise back up to near normal 17 at WOT and 18-19 at idle.
February 6, 201312 yr So I am going to replace the lift pump. I am looking at the rapter frrp. I know this is a constant battle, but what would you guys suggest? Which pump would be the best for me at a reasonable price? I am not looking for huge power. Having some rv275's installed this week. What do you guys think?
February 7, 201312 yr After putting in the Fass 95 and my own 1/2" line kit with draw straw to the VP, I have a constant 16-18 psi at idle and 14-16 at wot. And that is going through the stock filter housing that I retapped for bigger ID fittings. No more banjo bolts.
February 7, 201312 yr Sounds like a good idea. I already have a frame mounted fass hpfp. I also have a 3/8 big line kit from tank to vp. I think the pump is just getting weak because it holds steady pressure, it's just a bit low. 16 at idle and 13 at cruise. It does drop to about 9 at WOT. All I need is to replace the pump. I don't really need all the accessories and stuff for it.
February 8, 201312 yr Mine is 17psi at idle, and 15 at WOT with the Edge on 5x5. That's with a Fass 150HD and the stock fuel basket
February 16, 201312 yr raptor 150, vulcan draw straw, 2 micron cat filter, 1/2 lines 18psi @ idle, 17psi @ WOT im sure if i were running a wire tap box it would drop to 15-16@WOTi run a mechanical FP gauge, with no isolator
February 23, 201312 yr Got my new regulator from Stefan, (it's kinda like the Airdog regulators - ball & spring) and I got it adjusted about as good as I'm gonna get it. When I first start the truck, I got about 14 1/2 PSI, and then it'll settle at about ~13 PSI idle. Going through the gears, it's hard to get the pressure past 21 or 22 PSI. 3rd gear at 2,500 RPM it was at 25 PSI, so it's not that bad. . .
March 3, 201312 yr Owner With 30K miles on the AirDog filters I'm now down roughly 1.5 to 2 PSI from my 19 @ idle to 17 @ WOT. It's hard to tell exactly because of the cold fuel is lower in pressure anyways.
March 12, 201312 yr Owner Well tomorrow I'll be digging into the truck and doing some maintenance and repairs of miscellaneous things like adding my MPG fooler as a permanent switch, changing brake fluid, and changing fuel filters. It's been over 30K miles...
March 12, 201312 yr When I install my new raptor, I intend to put a Baldwin bf1212 before it. What kind of micron rating would that filter have? It had to be better than the stock one I'm thinking.
March 14, 201312 yr Fuel Boss, 17 at idle, 21 WOT, with comp box off. I wish I could get my Assassin to do that.
March 14, 201312 yr Mitusa pump, idles at 15.5-16. Any throttle and it jumps to 17-18 and never dips below that, even at WOT.
A poll to help with quick look at vitals.