GrampZ

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
...

http://users.adelphia.net/~teamtofu/yah/LIFTPUMP.jpg

Hillcountry

Thanks so much for posting this. I have noticed the same results with my 4601HP on the framerail...and I have been thinking of running a Holley Blue back by the tank to keep the pressure up. This will give me the motivation to do it this weekend. I have two relays and I plan on running both pumps off of relays so the voltage is constant.

Hopefully it works as it did for you.
Thanks

GrampZ

Yeehaw! Just got back from a 160 mile freeway run into L.A. and back. I had 14.5 psi SOLID all the way. Idle or dragrace from a light, it did not waver a needle width the whole way. Amazing! And you can believe I had my eye on that gauge every few seconds...
If you still have a good stock lift pump, you could do this dual pump setup for a little over $100 or so depending where you get your parts. I'm lovin' it so far!

GrampZ
SoCal

GrampZ

Austin eh? I was born in San Antonio but was an army brat and moved all about the country after. Been in SoCal for many years but have been through Texas hill cty. a few time recently.
The wife and I love the area. Been thinking about looking around the Austin/New Braunfels/San A./Kerrville area for a future move. You're lucky!!!

GrampZ

greasemonki

hmmm... I'm down to 12 psi at idle with mine (it was 14 when i first put the gauges on). I think I've found my project for the weekend. Thanks for the post

GrampZ

If you order your 74213 Carter pump from your local parts dealer(better if you know him personally!) it comes with a short wiring harness. This harness has both ends you need to make up the relay/rear pump,control cable. I just bought a relay at NAPA but you can get one at Radio Shack as well.
Good luck. If you need help, holler!

Oh yeah, you need a compact tubing cutter. I found a "made in USA" tool at Sears that fit the bill. Very compact, did the job, AND put beans on the table of an American worker.

G

greasemonki

I work as a mechanic, we are on the "kids play together" relationship (I dont have any yet, but my boss does).We make a quick phone call and get whatever it is, delivered, usually in about 15 minutes .

GrampZ

You're up late for EST!!!

Gz

Mopar1973man

Well let me throw 5 cents to the pile...

I'm using a Vulcan Big Line Kit which happens to be 1/2" fuel line from the tank to the VP44. I've measured the stock steel lines and they measure down to about 6mm. Too darn small for these engines...



Then I dumped the stock LP pump out... Then ordered a Carter campaign pump. Mounted it as close as I could to the tank.



Now I'm seeing 15.0 @ idle and 13.0 @ WOT which in my book isn't bad at all. 2 PSI loss for WOT is good... Now if the pump weaken over time and my WOT pressure drops to 10.0 I'll be pulling this pump out and replacing it... Being I only paid $46.90 for the Campaign pump from Cummins.

GrampZ

I've seen quite a few mentions of the Campaign pump but couldn't find specific info on getting these. Do you just drop by the Cummins shop and buy them or do you have to exchange for it? At that price, I'd like to stock up!! Details please!

Mopar1973man

You can get it at any Cummins shop...

Carter Campaign Lift Pump (PN# 4090046)

And there is the Cummins part number behind it... I got mine at Rocky Mountain Cummins in Boise, Idaho

The pump looks identical to stock OEM lift pump but it has been redesigned for the Cummins... The kit comes with a low pressure switch, tapped banjo bolt, new sealing washers, and the wiring for the switch... Instruction even too!!!

J BODY

Big line kit "from the fuel tank". I would think that would be overkill since you are still having to "pull" fuel through that tiny orfice on the in-tank module.

dieseldodge

but wouldnt the bigger line make like a resovoir for fuel which in turn giving more volume along with pressure?

nitrousn

A bigger line can allow more volume. The only way the pressure can increase is if a restriction is removed. The banjo fittings are more of a restriction than the lines.

Mopar1973man

Either way guys...

My fuel pressure has improved over the stock lines I had... My old fuel pressure numbers where 7-8 PSI @ WOT and now with the Big Line Kit its 13 PSI @ WOT. I would say that the restriction in the tank must not be to bad.