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Lift pump suggestions


angus

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I will definitely go for a mechanical when the chance comes up. Both brands of pump make it really simple to run the electric pump as back up via a hobbs switch. If something happens to the mechanical pump it will automatically kick in the electric pump. Otherwise, the mechanical pump will always work as long as the engine is turning. Belts are cheap and easy to replace and I like the fact that the pressure will build with engine speed. You aren't at the mercy of the alternator to keep the juice coming for the electric pump.

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I will definitely go for a mechanical when the chance comes up. Both brands of pump make it really simple to run the electric pump as back up via a hobbs switch. If something happens to the mechanical pump it will automatically kick in the electric pump. Otherwise, the mechanical pump will always work as long as the engine is turning. Belts are cheap and easy to replace and I like the fact that the pressure will build with engine speed. You aren't at the mercy of the alternator to keep the juice coming for the electric pump.

 

I don't think the pressure builds, as they have a pressure regulator. The available flow does increase thou.

 

One problem with the high flow rate is filtration, it's very easy with a mechanical to outflow the filters.

 

 

What happens when the electrical pump goes bad and you cant pull through the pump?

 

All the mechanical pumps I have looked at have their own pickup, so they don't pull thru the pump.

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So there is a "t" fitting so it can run off of electrical or mechanical? Will they start when the electrical goes bad?

Im just trying to figure out how this works for future customer pickups

 

Yes they "T" into the same feed line, but I am not sure where.

 

According to a post in this thread they will start with a bad electrical pump.

 

I have a Fluidampr so a mechanical isn't a possibility for me.

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Well, everything went pretty smooth Sunday. The hardest part was trying to figure out where and how to mount the assembly inside the frame rails. I found a nice piece of barn door hardware at tractor supply that served as a stand off to clear the return lines. The pump motor is barely audible without the engine running , and makes 22psi (idle) at the CP3. The particulate filter wound up hanging about a half inch below the frame rail, but you have to really get down and look to notice it.

 

All in all I`m pretty pleased so far. I`m thinking of backing the pressure down a bit?? 22psi seems a little overkill for a CR engine?

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Thats 22psi after going through the OEM filter canister. I bought a Vulcan big line kit from the can to the CP3 with a pressure tee. I don`t have a gauge inside the truck yet, so I`m not sure what WOT is.

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Just curious here. What happens to the CP3 if to much lift pump pressure is run? I know on the VP's you run the risk of blowing the front seal out in the pump.

 

 I don't recall exactly what happens, and I don't think a little too much will hurt (IIRC Dork is running low 20s).. they can get noisy, but otherwise I don't recall.

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Just curious here. What happens to the CP3 if to much lift pump pressure is run? I know on the VP's you run the risk of blowing the front seal out in the pump.

 

 

IIRC;  there was a fellow by the call name of "SuperDuty" on CF.  He transplanted a CR Cummins into a Ford chassis..........don't remember the year of the chassis though.

 

Anyhow;  he was the first PROPONENT of the little Walbro pumps as viable LP's for our trucks.  He had several STICKYS/ARCHIVED posts about his dealings with LP's on the CR's.  Don't know if Michael would be able to find those or not.  It's going back almost 10 years now!!!

 

Anyhow;  SuperDuty said that the factory plastic FF cover could handle over 60psi before cracking/breaking/leaking.  IIRC;  he said that he didn't run those pressures, but that it was a good thing to know. 

 

In his first forays into the Walbro pumps for our trucks;  IIRC, SuperDuty didn't use a true "regulator"......................instead he used a fitting that looped back into the tank return line.  The CP3 took what it needed and it was fine.

 

When GDP expanded on this;  he did use a "regulator" to satisfy his customers.  Richard told that to me directly!!!

 

 

I guess what I'm trying to say here is that the CP3 is not pressure dependent.  It need flow/volume, not pressure.   My wiring harness to my CP3 failed about 5 years ago.  Because the pump was still fine, and it was an electrical SNAFU.............my CP3 was still able to draw fuel thru the Walbro LP.  Had the pump seized, I think I would've been stranded!!

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I have read that the FF cover is only good to 30psi, by most accounts... But I have never tested it. I gather the o-ring gives out and it starts to leak.

 

While he may have had good luck with a lot of pressure to the CP3 others haven't... So it comes down to what is recommended vs what works for others. When I first started on the CR scene 7 years ago CP3's were getting a lot of pressure, as Dork's10 year old memory eludes to, now they don't. Heck you can't even find the Walbro pump for sale anymore from GDP or other diesel retailers. I think it was a good design, but failures were occurring and they lost out to AD and FASS.. thou I am not always convinced that was a improvement.

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Talked to a BD tech today and he says the Max Flo pump is regulated by different springs in the pump head. Its supposed to ship with the light spring installed 15psi and the optional 18psi spring included which I did`nt find. 22PSI is not considered normal for this pump. He wants me to check the spring and piston cup first to make sure something isn`t stuck from sitting on the shelf.

 

So I`ll see where this leads.

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I have read that the FF cover is only good to 30psi, by most accounts... But I have never tested it. I gather the o-ring gives out and it starts to leak.

 

While he may have had good luck with a lot of pressure to the CP3 others haven't... So it comes down to what is recommended vs what works for others. When I first started on the CR scene 7 years ago CP3's were getting a lot of pressure, as Dork's10 year old memory eludes to, now they don't. Heck you can't even find the Walbro pump for sale anymore from GDP or other diesel retailers. I think it was a good design, but failures were occurring and they lost out to AD and FASS.. thou I am not always convinced that was a improvement.

Richard from GDP told me when I bought another wiring harness from him for my Walbro..............that he stopped selling his Walbro system because Walbro wanted him to buy a HUGE amount of pumps at one time for a decent price break.   Richard just couldn't have that $$$ tied to inventory to stay competitive, so he dropped his fine Walbro set up.

 

The Walbro pump was not failing per se, nor was it the weak link in his system.  I think many failures were due to CP3 ignorance at the time and the fact that guys were doing stuff without thinking too much.

 

My FP is read PRE OEM FILTER.  Sometimes in the Winter, my 30psi Autometer gauge is pegged if I leave her outside overnight.  Summer time it runs 24-25psi.  Have no idea what the pressure is at the CP3 after going thru a 7micron Fleetguard and a 2 micron secondary Fleeguard filter.  Any idea about the pressure drop across the filters John???

 

No leaks from my OEM FF cover or gasket ever.

 

Just saying, and "I think" my memory is still good......................I don't remember though

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24V guys stepping in here...

 

Like with 24V engine I only suggest 4-6 PSI over design pressure this allows for buffer room to keeping your minimum pressure met at WOT runs. If you getting pressure fall out during WOT I would typical suggest looking for restrictions like plugged fuel filter, kink line, weak pump etc. But really there should be no reason for over pressurizing the system to over design failure. We had guys running old mechanical lift pump from 12V's running up to 40 PSI on a 24V and the risk you take is popping the front seal out of the VP44 well in your case the CP3.

 

So to the OP I would get a gauge in the cab ASAP then tone the pressure down a wee bit and get back to a normal range.

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24V guys stepping in here...

 

Like with 24V engine I only suggest 4-6 PSI over design pressure this allows for buffer room to keeping your minimum pressure met at WOT runs. If you getting pressure fall out during WOT I would typical suggest looking for restrictions like plugged fuel filter, kink line, weak pump etc. But really there should be no reason for over pressurizing the system to over design failure. We had guys running old mechanical lift pump from 12V's running up to 40 PSI on a 24V and the risk you take is popping the front seal out of the VP44 well in your case the CP3.

 

So to the OP I would get a gauge in the cab ASAP then tone the pressure down a wee bit and get back to a normal range.

The Tech guy at BD is sending me some different springs to try. He said they do have higher pressure springs that cater to the extreme performance crowd, but the pump should have shipped with the lightest spring installed.

 

The truck seems to run just fine at 22psi, but I want to get it dialed down to around 12-15 @ idle.

 

ON THE GAUGES topic.. I kind of like the three gauge dash pod I have seen for the 3rd gen trucks.

 

Anybody have any experience with these ? or getting to the forward underneath part of the dash?

It looks like a guy might have to disassemble half of the dash to get back there.

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