LorenS

I'm not sure why one would use this over an air removing AirDog or FASS, but for an ELECTRIC pump has anyone heard of using a Holley Dominator? Only some sizes (100 and 200 GPH) are Diesel compatible, for some reason unknown to me. I think if I was looking for a frame mounted, non-air removing lift pump, I would choose this and the external regulator over the DRP (which I have) or Raptor 100. Anyway, this post is just for bench racing, if you will. Love to hear other's thoughts. https://www.holley.com/products/fuel_systems/fuel_pumps_regulators_and_filters/fuel_pumps/carbureted_fuel_pumps/carbureted_electric_fuel_pumps/parts/12-1800

I decided to "fix it 'til it's broke"

What are the thoughts on returning to the filler neck during the summer, and back to the stock basket in the winter? I'm thinking a 3-way valve or pair of ball valves, not physically moving the hose. If i switched it every March and October, that should eliminate my hot fuel in the summer months and give me the benefits of warmer fuel during the winter while in northern IA, Minnesota, etc. When I installed my draw straw and cleaned the basket, I accidentally tore off the fine 'screen' on the bottom of the basket and now have 1/4 tank issues in a BAD way! Will "run out" of fuel with 7 gallons still in the tank. Very aggravating to bleed injectors in a BUSY intersection merely because I went over a raised set of railroad tracks and all the fuel ran to the front of the tank.

I did another 400 mile trip today, home from Minnesota. Started with a full tank. It was about 88 degrees the whole way, according to overhead console - and humid. It took the whole trip, but fuel temps finally got over 150 degrees. IAT was generally around 125. Any time traffic slowed to 55 MPH for several miles, the fuel temp would drop several degrees, then we'd get going again and soon the fuel temp would be up again. Fuel pressure on ISSPRO would be consistent 16-17, then sometimes climb to 18-19 and then would fall to around 13, then go right back to 16-17 again. To me that sounds like a relief blowing off when I'm at 16-17, then shutting for several seconds so pressure rises to 18-19, blowing wide for several seconds to drop to 13, then finally the spring partially shutting the relief. But as Mike stated, relief failure is rare. This climb and then drop isn't very regular, and has nothing to do with engine load, throttle position, a head wind, or anything I can easily observe as a correlation. On my way to Minnesota on Monday I essentially hot wired the pump at the relay (load terminals, not the signal wire). The pressure wasn't any more consistent, it behaved the same way. It was very nice weather, only 68 degrees, so the fuel never got near 150, but was still 50 degrees hotter than ambient. Unlike you guys with a decent amount of fuel going to your filler neck, all my fuel just goes in a circle, right back to the factory sump/sending unit, so could it be that that fuel is just slowly getting super hot from that? I haven't measured the temperature of the fuel elsewhere in the tank, nor double checked that the computer isn't lying about the temp. It's not lying in the morning, reported fuel temp is near ambient. Should I plumb my return back to the filler neck? I rather hate to do that as it adds more splices and could entrain air in my fuel as it splashes back into the tank, and also in the winter that warming of the fuel has to be a good thing, right? I bought the $300 DDRP before I found this site, and don't really want to drop another $650 on yet another fuel pump just to remove air. Of course, there are a lot of things in life I don't want to do, but do anyway because it's better in the long run.

And with that, I'm through trying to intelligently discuss this topic. Have a pleasant evening.

If you have a relatively fixed orifice (the relief valve) then in order to get huge flow you need high pressure. Just like with DC electricity, if resistance is fixed then voltage (pressure) and amperage (flow) are proportional. Perhaps that is true. I have about as much faith in "technical writers" as I do engineers that eagerly wear ties or skirts to work. And I am an engineer who grudgingly wore a tie for six years - I'm now back where I started, wearing Carhartts and a Cummins ball cap or hard hat. However, we all know that 70% return is NOT just from lift pump pressure, there is a lot that is returned from downstream of the internal rotary vane pump. In fact, because the specification for the lift pump is 10 PSI and the relief valve is set to 14 PSI, it would APPEAR that the designers intended none of that return flow to be caused by the lift pump. I say appear because all we have is the technical writer's (likely wrong) interpretation. I believe over 15 PSI at moderate throttle is a very good thing to keep fuel temps low. Whether or not this is required at WOT when large volumes of fuel are passing through the pump, I am not certain. But my Vegas money is on "no". Your electric lift pump is putting just as much - if not more - fuel through the VP at WOT as it is at idle. And so is a mechanical lift pump, at a given engine RPM.

At WOT, I can't imagine you need the relief to be open. The fuel you're burning is still passing through the VP absorbing heat.

If it was Montgomery Wards of the 40's and 50's, I think I'd love to spend a few hours there! Looking at old catalogs they had some really cool stuff way back in the day. I have an old Powr-Kraft table top drill press I used to use until I broke a cast sheave. It's splined, so finding a replacement has thus far proven impossible, even McMaster Carr, etc. haven't been of any use. I agree that NAPA is generally much better, but there are exceptions depending on the store owner's hiring decisions. The O'Reilly's where I used to live had a guy in an office, not behind the counter, and he was the guy you needed to talk to if it was mildly complicated. For instance, a Continental engine, and not a Lincoln Continental... Pretty sad state of affairs these days at the parts houses.

I'll bet a dollar that Mopar1973Man recommends NAPA

You guys crack me up! I'm still in the <235 HP range with my HY35 and stock (but fresh) injectors. Hence my reading older posts about turbos

Yes, that's a perfect example! The lights are amazing.

Yes, that's the one. My truck must have had aftermarket seat covers most of its life, because the fabric isn't faded. It does have a big rip right in the middle, but I run some high-dollar (Covercraft?), heavy duty seat covers, too, so the tear hasn't grown. Otherwise I would have purchased the new fabric, also. Taking the old fabric off was the hard part because of the big clips that snap onto the steel part of the seat. A couple of them were very stubborn. I reused my existing hog rings with the help of two pairs of pliers, they run left to right holding down the center of the seat fabric. I have an 01 so didn't remove the entire seat, have no idea why they say to do that in the instructions; supposedly 94-97 guys have to do so. Cost for just the foam is rather high at $125, but having experienced the change I'd very grudgingly pay twice that. Any higher and I'd just cobble something together under the original foam!

I knew the ECM would modulate the lift pump, but I just looked up the standard operation in the FSM and learned it only does that during cranking! I incorrectly assumed it had an algorithm to know how much to pulse. Before I assume that part of the ECM is dead, is there anything else it could be, like a pressure relief valve that has a "hitch" in it? If not, I'll be doing the IBMobile modification - I currently don't have an operational backup vehicle (1986 military Blazer has sat a long time).

Just took about 30 minutes and installed my new driver's seat cushion from Geno's and I wish I had spent the money 50k miles ago. It is SUCH a drastic improvement. No more smashing my tailbone on the rear crossbar with every bump!

If the ECM isn't triggering the pump to operate, I could have 3" pipe and still not have 18 PSI.

I have 3/8 from tank to stock filter, then 1/2 from filter to IP, all banjos removed. Since the pump puts out great and consistent pressure when jumpered, I believe the ECM is "pulse width modulating" the pump for some reason. For my 400 mile drive home I plan to jumper it just to see what happens. Fuel got to 151 today and it was only 88 degrees out. IAT was 125. Flat Iowa terrain.

I didn't say cooler, I was referring the humidity we have here when I said sauna. It seems you agree our trucks are very different. @dripley The IBMobile mod to which I refer is where the lift pump relay is triggered by a wire (orange and black?) from the PDC that will cut power in the event of a crash, instead of being controlled by the ECM. My fuel pressure rises and falls around 13 to 18 as I drive, but if I shove a jumper in the wiring to power the pump it's consistently up around 18-19.

I get that, but our trucks are about as different as they are similar, so I don't know how much stock to put in comparing temps. The big differences are that I've got dinky injectors at stock pop pressure, a dinky turbo, a slushbox, and operate in a sea-level sauna compared to Idaho. My truck has also been used and abused before I got it (36k pound plates?!), whereas I recall you bought yours new and surely took care of it. And yes, I'm running giant 3rd gen stock tires with my 0.69 overdrive. We have so many differences it's hard to know why my fuel temps are reported as high. For all I know the sensor is bad, my return line is restricted, or since my injectors are small the solenoid has to be energized longer each injection cylce and thus puts more heat in the fuel. Most likely if I did the IBMobile mod the temp would come down. Maybe my relief valve isn't up to snuff.

With relatively fresh stock injectors, 3.55 gears and HY35, is 17* at 1900ish RPM on a slight hill extremely conservative? I see 20* going down hill, that's about it. I haven't tapped the pump so just utilize levels 2 and 3 on Quad. I think I'm running one of your tow tunes for stock trucks that I bought.

Around 118. I think the ECM was doing a lot of pulse width modulating because the pressure would go up and down with a fair bit of regularity, 14 to 17. Then sometimes it would go up to 18-19 for a few seconds. I could not deduce the pattern looking at IAT, boost, load %, fuel temp. I almost tied my relay into the wire that IBMobile recommends if the ECM loses the lift pump circuit, but really didn't want to put a splice in a perfectly good wire.

I don't believe the new pump helped much. Fuel temp reached 141, and it's 10 degrees cooler out. I did have an extra 1,000 pounds in the bed, so the test is far from definitive.

Installed the DRP late this afternoon, bumped starter and achieved 19 PSI. Have over 800 hundred miles to drive this week so we'll see how fuel temps turn out.

That's good advice. My FASS is just the wimpy FASS, with no fiters. It's the DRP model, just 80 GPH and was designed to sit on the engine block like the Carter. I have my pump situated inside the frame rail near the skid plate instead of RIGHT by the fuel tank. Likely because I saw the photo of your setup and found it to be quite wise. The filter I mention looks like an old inline filter for a mid-90's GM truck, but with hose barbs instead of threads. 150 micron screen, nothing fancy.

On Saturday I put the lift pump on an ECM triggered relay, which (to no surprise) didn't raise pressure, even when 'hotwired' with a jumper instead of the ECM. On Sunday I replaced the existing Carter lift pump (frame mounted) and at first the pressure went down some. Now after 150 miles or so the pressure is in the 14-16 PSI range at low load and must be opening the relief valve as my fuel temp is more in the 109 range versus +140. My assumption is that the vanes finally mated to the stator(?) and there's less blow by. The thing is still as loud as the old one. Speaking of the old one I disassembled the pump end and it look great. No trash of any kind in the inlet screen; I thought perhaps there would be from when it was mounted on the block. When relocated to frame I put an inline screen ahead of it, the one that comes with FASS DRP units that they say to replace every 5k miles. I ran the thing 20k miles, I'd guess, and it was clear, too. I guess I have been pretty lucky and wise in my fueling station selections! I freely admit I find the newest or best-maintained fueling stations at which to buy fuel. If they don't bother to change burned out bulbs or do touch-up painting, what are the odds they maintain their tanks and filters? Once I buy or fabricate a suitable mount the FASS pump will get installed. I bought it in 2017 and never installed it because I only wanted to run it off of a relay. Well, I finally made the harness then realized I didn't have a suitable bracket! Geno's used to have them for $8, but no longer. Will need to root around the scrap iron pile for some 3/16" strap, etc., and get after it.

Hard to go wrong with JAG1's recommendation. Price is right. http://www.vulcanperformance.com/mobile/Product.aspx?ProductCode=FFIP59 Vulcan also has other pieces and parts. On my truck the port connection is on the AN style 90 at the VP44, but it's not a long sweeping elbow. Like this, but tapped for connecting pressure transducer. http://www.vulcanperformance.com/mobile/Product.aspx?ProductCode=650066 Don't hook the transducer directly to this location or it will be ruined. Many recommend air brake tubing to remote mount mount the transducer, due large volume to dampen pulses. I am the black sheep who uses a snubber and a grease hose - yes, zip tied to the power steering hose. So far, so good, but that's only 50k miles.