rickf

I have a problem that is bothering me. I suspect the lift pump is going bad but I want to be sure before Idrop the money on a new one. This has been a rough couple of weeks and money is tight.
I had my gauge acting up and bouncing all over (Glowshift). They sent me a new sender and all was good. Took it for a test ride and verified that I had pressure. Not real good pressure but 12lbs. at idle and 6 at WOT with the Quad on. Was talking to a friend and the pressure just dropped to zero. Power off type of drop, not gradual. Truck stayed running. Shut it down and restarted it and pressure came up for a little bit and then off again. Put a mechanical gauge on along with the electrical and verified that it is shutting down. Tapped on pump to no avail. This was a NAPA pump bought three years ago. At that time I had bought the truck and found that it had no fuel pressure, Nobody knows for how long, previous owner told me it always ran well. So this si the second time. My VP is on borrowed time but right now I need to know what you guys think is the issue here?

Rick

totalloser

Save yourself a headache and some money. Don't put a stock pump back on.

Carter makes pretty much the same pump but with NPT fittings and they sell for about $100 versus $240 (if I remember right) and comes with a rubber isolated frame mount kit and nipples. Napa had mine in stock and it looked nearly identical to the pricier factory style. In fact other than the wiring connectors and fuel fittings, it appears to be the exact same pump.

Mounting the pump on the framerail puts the pump below the tank (no dry priming) and isolates it from engine vibration and heat. It will live a LOT longer and be way more reliable.

If you go this route, wire in a relay to run the pump so the pump load is off the stock wiring. Use the stock wiring just to operate the relay. The stock pump is run by a relay that is INSIDE the pcm so if it goes bad you have to crack the pcm. I used a stock style relay to do this on mine. Be careful how you wire it up, put the hot on the switched side, not the switch side of the relay so that when it's off there isn't a hot tab just sitting there exposed. Look at the diagram on the relay and you'll see what I mean.

I'd REALLY try and avoid running the engine with the lift pump bad, it might cost you an injection pump.

whiskers

I agree with TL, but not with the Carter. They don't put out the best pressure, Go with a fass or raptor. Much better pressure for your IP. The fuel flow is what cools the IP.

high bid

LP is going out. Mine did the similar thing. I replaced the factory w/one from rock auto. I have one frame mounted Holley w/filter and the rock auto Factory replacement LP and have way more than enough fuel psi. From the psi after the LP install I could just run it and have plenty of fuel. Good luck

totalloser

Whiskers has a good point with the fuel flow, but there are two other solutions: First is to drill out the major restrictions in the fuel system- the banjo bolts. Some trucks come with the bigger ones (mine did) and you also can buy oversize ones. Geno's garage carries them.

The other is to run dual lift pumps. I ran dual for a while, but ran a second relay to prevent "hard starting" which is common with higher pressure. I pulled the factory one back off though. At my hp (400-450ish at the crank) I doubt I need it. The Carter pumps are internally regulated so they double the max pressure when inline. I had mine wired to kick the engine pump off when engaging the starter, but a better way is to get a "T" off the oil sending unit on the block and put in a normally open Hobbs switch (pressure switch) and have that run the second LP. This makes the second stay off until the engine oil pressure is up. It also prevents the upper pump from dry priming.

And again, the Carter will bolt right into the engine bracket, just different fittings- use npt nipples and regular fuel hose. Dual pumps will cost about what the single stocker costs. And you can do the second LP later as things are tight right now as stated in original post.

rickf

Well, I went with the DDRP from FASS and I am now sorry I did. 10 lbs. at idle and drops to 4lbs. under mild acceleration. Not even drivable! I have a call in to FASS and to Geno's Garage where I bought it but that does me no good at this point because now the truck is down for another week.

Thundercraft

Wonder if there is a restriction in the pickup line somewhere?

BigIron70

Did you clean the pickup screen in stock tank when you put sending unit in? Transfer tanks are known to rust and get water in them.

rickf

I'll answer the last two posts in one reply. My transfer tank is a aluminum saddle tank from a big rig so no rust there plus I run a filter between it and the main tank. I have not had that installed for the last year or more. I thought about a restriction but my old beat up NAPA replacement pump was putting out 15 lbs. at idle and 8-10 at WOT. The reason I had to replace it was that it was cutting out electrically. I figure if the stock pump can put those pressures out then there is nothing wrong with the pick-up. The tank is full so it is not having to lift it very far.

scottsjeeprolet

Stupid question , but check that you plumbed the pump up correctly. Had a friend hook his up wrong once. It still ran but at reduced flow.

rickf

The DDRP can only be hooked up one way unless they mounted it to their bracket at the factory wrong, and marked it wrong.

Beatle

I had the same problem with junk sending units with Glowshift 4 later. Get them to upgrade you to a Elite 10 or Max diesel fuel guage they come with the transducer instead of the old sending units (Junk). I went with the Raptor FRRP works great only had it for 8 months now. Same unit as Raptor pump. I use it as a Aux pump with intank pump works great 20 psi pulls down to 15psi. One thing about the FRRP you can crank up the psi to what you like.

rickf

I am using a mechanical gauge to back up all of my readings, I did not trust electric gauges that much either but that said the Glowshift is within 1/4 lb.. I have seen way too many horror stories about Airdog products since the change of ownership. More bad than good. If you are using that pump along with the intank pump and still pulling down to 15 lbs. then something is wrong. Also, if that intank goes out you will cook the Airdog in short order trying to pull through the dead intank pump. You can pull some through but if you need a lot of volume then there is to much resistance.

Beatle

Your right when the time comes I will pull the pump in the tank and go with just the basket and Draw straw 5 in the fuel basket. I have had the in tank pump now for six years no problems original owner had the pump put in which sucks. I added the Aux pump in the beginning. The biggest problem with the pumps is the brushes in the motors wear out from the continues running and they are not designed for this. I have opened up the Holley pumps and the same problems with all of the brushes are gone. The vanes in the pump half are fine. This is where the gauge works you can tell if either pump fails with the built in alarm in the Glowshift Elite set at 5psi. I see your Fass pump is in the same range starts 15 psi and drops to 8psi. Let me know if you get it in a higher range that is why I run 20psi and drops to 15psi and it runs there all day long. The only reason I went with the Airdog was the four year warranty I will end up rebuilding it also it is easy to do. I guess the best thing will be to go with the gear driven pumps off the crank.

rickf

Geno's Garage is THE place to go. I called them today about the issue since I bought the pump there and they are overnighting a new pressure relief spring to me along with a relocation kit I requested. Come to find out that apparently FASS had a bunch of these pumps leave the factory with the wrong springs, think they would say anything? They e-mailed me today and said "It sounds like you have a weak relief valve spring" They will send me a new one. Geno's had told me that FASS sent them a whole bunch of springs fully knowing there was a problem. They would not give out a serial number range though. I feel sorry for the people that put these pumps on without a gauge assuming it is a brand name pump and end up wiping out the VP and probably not even realizing why it happened. Then you have the ones that pay mechanics to do the work, TWICE! I feel sorry for places like Geno's since a lot of people will take it out on the distributor and not the main supplier. In this case the distributors had no clue until the calls started coming in. So now I get to do it all over again but this time in the rain and snow.