Implementing a Walbro fuel system
01-14-2006, 10:14 AM
#61
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SD, concerning the capacity of the stock fuel pump electrical system to handle the higher amp wahlbro, you said:
"If you look at the Walbro flow curve, you'll see that it draws 5A at about 10 PSI and 6A at 20 PSI and 7A at 37 PSI. I don't think you'll run much more pressure than that.
So... CP3 trucks using a plain bypass probably don't have to touch the relay. It will work fine because your backpressure at the pump is about 6-8 PSI with a clean filter."
Do you think that the addition of a 2 micron filter setup before the cp3 would draw a significant amount more amps to warrant modification to the relays?
"If you look at the Walbro flow curve, you'll see that it draws 5A at about 10 PSI and 6A at 20 PSI and 7A at 37 PSI. I don't think you'll run much more pressure than that.
So... CP3 trucks using a plain bypass probably don't have to touch the relay. It will work fine because your backpressure at the pump is about 6-8 PSI with a clean filter."
Do you think that the addition of a 2 micron filter setup before the cp3 would draw a significant amount more amps to warrant modification to the relays?
01-14-2006, 10:20 AM
#62
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BTW, if anyone with a 03-04.5 with a filter mounted pump is interested. I got the FASS adapter for replacing the stock pump from Rip at http://www.sourceautomotive.biz/
01-14-2006, 05:06 PM
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This has probably been answered somewhere in all these threads, but is anybody but me averse to idea of splicing in a pump with push-over fittings and little hose clamps?
Has anybody thought of implementing a system with full-boogey Milspec AN fittings and jet fuel capable hoses? I know that on aircraft the general recommendation is to replace hoses every five years, and hose failures are pretty rare. This could also get rid of the banjo bolts and replace them with nice angle fittings. I think it would also give a lot better, professional-looking appearance to the system.
Has anybody thought of implementing a system with full-boogey Milspec AN fittings and jet fuel capable hoses? I know that on aircraft the general recommendation is to replace hoses every five years, and hose failures are pretty rare. This could also get rid of the banjo bolts and replace them with nice angle fittings. I think it would also give a lot better, professional-looking appearance to the system.
I thought this was a fuel pump thread?
01-14-2006, 06:30 PM
#69
Administrator / Scooter Bum
A 9mm may expand, but a .45 will never shrink.
.....Meanwhile back at the ranch...........
did anyone see a fuel pump thread around here somewhere, I seemed to have lost one......
.....Meanwhile back at the ranch...........
did anyone see a fuel pump thread around here somewhere, I seemed to have lost one......
01-15-2006, 10:37 AM
#70
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SD, concerning the capacity of the stock fuel pump electrical system to handle the higher amp wahlbro, you said:
"If you look at the Walbro flow curve, you'll see that it draws 5A at about 10 PSI and 6A at 20 PSI and 7A at 37 PSI. I don't think you'll run much more pressure than that.
So... CP3 trucks using a plain bypass probably don't have to touch the relay. It will work fine because your backpressure at the pump is about 6-8 PSI with a clean filter."
Do you think that the addition of a 2 micron filter setup before the cp3 would draw a significant amount more amps to warrant modification to the relays?
"If you look at the Walbro flow curve, you'll see that it draws 5A at about 10 PSI and 6A at 20 PSI and 7A at 37 PSI. I don't think you'll run much more pressure than that.
So... CP3 trucks using a plain bypass probably don't have to touch the relay. It will work fine because your backpressure at the pump is about 6-8 PSI with a clean filter."
Do you think that the addition of a 2 micron filter setup before the cp3 would draw a significant amount more amps to warrant modification to the relays?
I don't know what to say about a 2nd gen truck as far as Walbro wiring goes. I've been told that the ECM controls the fuel pump electrical power and that it gets modulated down during start up. I've also been told that the VP44 has an overflow valve set at 14 PSI. If so, why does one need to modulate down the lift pump power ? Unless the lift pumps are totally stalled at 14 PSI ?
Anyway... I don't think I would run a Walbro off the ECM on a 2nd gen. Apparently the maximum draw on the 2nd gen fuel pump drive is 5A, and it is unclear to me if the ECM actively limits that current or if that is a specification maximum. I don't even own a Dodge truck, remember ?
If I had a second gen truck, I would either find a relay that will operate properly with the voltage the ECM supplies during startup OR I would wire a relay in to be controlled by the Key On voltage and run it from that. I don't think I would chance running a Walbro from the ECM until I had figured out exactly what comes out of the ECM to run a fuel pump.
01-15-2006, 11:29 AM
#71
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How about an oil pressure switch to run the LP? That way if the motor dies (say in a crash) the LP isn't running. Run a relay off the "start" terminal on the starter as well to provide fuel during starting.
01-15-2006, 11:42 AM
#72
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My Ford has a crash switch that turns off the lift pump. It supplies the power to the fuel pump relay. The relay is not powered directly from the battery, it goes through the crash switch.
I suspect the Dodge has such a switch too. I don't know anything more about it though. Maybe it depowers the whole ECM. How else would the ECM know the truck has crashed ?
I suspect the Dodge has such a switch too. I don't know anything more about it though. Maybe it depowers the whole ECM. How else would the ECM know the truck has crashed ?
01-15-2006, 04:47 PM
#73
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Originally Posted by Superduty
My Ford has a crash switch that turns off the lift pump. It supplies the power to the fuel pump relay. The relay is not powered directly from the battery, it goes through the crash switch.
I suspect the Dodge has such a switch too. I don't know anything more about it though. Maybe it depowers the whole ECM. How else would the ECM know the truck has crashed ?
I suspect the Dodge has such a switch too. I don't know anything more about it though. Maybe it depowers the whole ECM. How else would the ECM know the truck has crashed ?
Ahh, the good old inertia switch. Brings back memories of my old ford gasser.
I have no idea if Dodge has anything similar.
01-15-2006, 07:30 PM
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Originally Posted by linetrash75
sea01cummer, what size inlet and outlet fittings are on your bosh pump, I hope they are larger than 10mmx1 like the walbro pump.please respond.
Jed
Jed
I haven't measured it but it is close to 3/8. I have been delayed till next weekend on the install, the regulator came in as a 12-803, it should have been 12-803BP. They reordered it and it should be there monday. I am confident that this pump is going to solve alot of peoples lift pump problems. You guys need to keep a open mind about where this pump came from and give some of us a chance to install it , then we will go from there. I got the pump used for 35 bucks , so it is a realatively cheap thing to try. I know a PSD can run WOT at 450hp and keep fuel pressures at a psi that is plenty for us. I guess we will see, SUPERDUTY thank you for the help>>
Steve
