Engine/Transmission (1998.5 - 2002) Running two carter fule pumps

[TBrock]

I talked to some guys that are running two carters one in the stock location and one by the fule tank there using a relay switched by the front one and powered from ignition. Any thoughts on this set up, they say they are holding 15psi -13psi WOT and have had this set up for 30kka mi.



Thanks for the input

Thomas Brock

 

[klaybus]

I suppose it would\could work but I would think the pressure at idle would be a bit excessive with both pumps running... . My question would be, why would you want to run something with such poor performance (life span) X 2? That could get kinda expensive in a hurry with all the failures of the OEM Carter pumps IMHO.



Clay

 

[TBrock]

I would think that thay would olny work half as hard and last longer as far as pressure thay wont put out more then 15psi, I dont know just looking for some input.



Thomas Brock

 

[klaybus]

I would think that thay would olny work half as hard and last longer as far as pressure thay wont put out more then 15psi, I dont know just looking for some input.



Thomas Brock

I would think they the psi would almost double... 15 psi + 15 psi=30 psi +-. I guess my point would be their a typically CHEAP built pump. The last two I have taken apart with low miles both contained lots of metal fragments & it appeared to me the Q. C. has gone downhill over the past year or two... . Lots of failures. Just my opinion however. After installing my 7th Carter pump in 100k miles I just installed the Walbro GFS-392 pump. Time will tell if this is a viable solution, but I know with the Carter I WILL EXPERIENCE YET ANOTHER FAILURE.

Again, just my humble opinion... .



Good luck. I hope yours is better than mine.



Clay

 

[WestTN]

I replaced the original pump at 106,000 miles and used the Vulcan relocator kit from Genos Garage. Now my pressures are 14. 5 psi at idle and 13. 5 psi at full throttle and 27 psi boost. It is the latest model with the internal bypass.

I don't see anything wrong with the standard pump. I also don't try to run the tank dry before refueling since that can be hard on any DC powered pump due to severe overspeeding. The last thing is that I don't use any fuel additives except a biocide once a year. I now have 110,500 miles on the truck and have NO other repairs of any kind.

 

[MBFARMS]

That setup is called a pusher pump setup. Many ways to do it. Do a search for pusher pump and you will get hours of reading. Usually you keep your stock pump and add a second pump that works at a lower PSI at the tank. I think most people are using a Carter 4601, don't quote me on that. Jegs, summitt and others sell that pump. Gary - K7GLD has a nice pusher setup, might want to look at his pics to see them.

 

[TBrock]

This is a post from another diesel site



I hope!



For the last week I have been trying to improve the fuel pressure performance on my '00 truck. I have been through 6 LPs in 85K miles. The last one was just getting a little soft so I thought I'd try to do something else this time besides just replace it(BTW, I can now do a LP on a cold engine in 12 minutes!, plenty of practice... ) I usually see 14~15 psi@idle and 9@WOT with the stock pump.

So I thought I'd move the location down by the tank on the frame. I went to the parts store and my buddy talked me into a 4601HP. Specs said 18 psi and plenty of flow. I mounted it on the frame and it showed 10 psi@idle and 7 or 8@WOT. Bummer! I called Carter and the tech explained that it WILL make 18 psi but only if you restrict the output. So the pressure was governed by the load at the VP44 apparently and was not building up past that point due to the bypassed fuel at the engine.

I returned my stock 74213 Carter on warranty and put that pump at the new location on the frame. This was a disaster. I only saw 10 psi@idle and when you really stood on it, it would suddenly drop to ZERO psi. What the... ?!

Part of this may be due to the line I had to run from the pump to the filter. I did not yet have the special 12mm fittings to run 3/8" hose all the way and had to juggle the banjos around and had to use 1/4" from pump to filter housing. I cannot guess how much this would improve with bigger hose but it was scary watching the gauge drop to nothing!

Last resort was to put the stock LP back on the engine and put the 4601 on the frame as a booster/feeder for the other one. I did build a harness and ran a relay and larger wire to operate the rear pump.

the setup is now inlinefilter----3/8"----->P4601HP---3/8"--->74213----3/8"-->VP44

I did not know what to expect from this setup but it appears to be ideal. It is running 14. 5 psi from idle all the way to WOT. Not even a wiggle! I was really glad to see it was not running off the top of the gauge and the regulation is impressive.

The proof of the setup will be in how long these pumps will function as opposed to past experience. I have a feeling the front pump is going to be much happier being force fed and not having to suck the fuel up from the tank. I have read some remarks about the 4601 pump concerning reliability. I am confident that this would work equally as well with one of the Holley pumps and if I end up having a problem with the rear pump I plan on trying a different brand.

The one thing that would make me happier would be getting the front pump out of the heat/vibration of being mounted directly on the engine. Quite a few people suggested that was contributing to the short lifespan.

The tech at Carter said he kept notes and had talked to a lot of people about this particular issue and he even suggested the dual pump setup, adding that consideration needed to be given to the electrical feed if that is done. Very nice fellow...



Here is a graph of was I was seeing with each of these arrangments

 

[OPoole]

I have used the carters for a few years now the die left and right. I do have one on my truck now and one under the seat! But not for long i have a new FASS 95/95-1008 going on as soon i get time for my own truck??

 

[klaybus]

I know many have run pushers & they do work, but for how long? I'm hoping the Walbro continues to perform but short of a mechanical pump anything we install electrical can & will fail. :{ I just hope the prices of the mechanical pumps start dropping sooner rather than later... ... .



Clay

 

[OPoole]

Do you have a aftermarket cam? F1 cams has the lobe for a mechanical pump.

I have ran just one carter 15lbs pump back by the tank for 26,000 miles now but i do keep one under the seat. Yes it has worked and i have made 600hp with it and it is a noisey little thing! There about like a VP-44 some last and some don't.

 

[mhenon]

After having my VP replaced by the dealer they installed the in-tank pump. I wasn't too happy with the pressure put out by this pump (7psi @ idle... "0" psi WOT) and finally went after market.

The fuel system now looks like this: in-tank pump goes to a 20 micron filter/water seperator... then to a Carter pump mounted on the frame... into a 2 micron filter and straight to the VP (removed the stock filter).

All of this is running through Vulcan big lines and fittings (no banjo bolts). Glacier supplied the filters and mounts.

So far it's been running about 25 psi at idle and 22psi at WOT. I'll have to see how it holds up. It will run with either pump off by the way (I checked) so I could limp home if one poops out.

Mike

 

[Larry Willard]

I have been running the set up you ask about for 100000 miles now. I was on the 3rd pump and it was holding 5 pounds or less towing when I added the 7 psi pusher, and it kept the poor stock pump for 60000 miles before I finally replaced it. I still am running 13psi wide open.

Larry