frank_ster Posted February 7, 2013 Share Posted February 7, 2013 i was reading that the warbro 255 is more efficient its what i have. and i had on my sunbird. also if you had larger injectors and the fuel pressure went down to 40 lbs ish due to lack of supply .. the pump wont have to work as hard. there was a forum some where, they compared the fuel flow and currant draw of each pump over a wide variation of conditions. Now that's thinking out of the boxer! fyi all 05 + legacy's have built in code reader Link to comment Share on other sites More sharing options...
Scooby2.5 Posted February 7, 2013 Share Posted February 7, 2013 So no good replies? Maybe your aeromotive is faulty... it wouldn't be the first one. Aeromotive fixed it. Did you read the thread? Link to comment Share on other sites More sharing options...
Scooby2.5 Posted February 7, 2013 Share Posted February 7, 2013 i was reading that the warbro 255 is more efficient its what i have. and i had on my sunbird. also if you had larger injectors and the fuel pressure went down to 40 lbs ish due to lack of supply .. the pump wont have to work as hard. there was a forum some where, they compared the fuel flow and currant draw of each pump over a wide variation of conditions. One of the studies I posted in this thread, you might have to go back a few pages though Link to comment Share on other sites More sharing options...
mwiener2 Posted February 7, 2013 Share Posted February 7, 2013 Aeromotive fixed it. Did you read the thread? If the Aero fixed the problem, you wouldn't be re-wiring your FPCM. My Mods List (Updated 8/22/17) 2005 Outback FMT Running on Electrons Link to comment Share on other sites More sharing options...
KCwagon Posted February 8, 2013 Share Posted February 8, 2013 (edited) If the Aero fixed the problem, you wouldn't be re-wiring your FPCM. MWeiner's 12,146th helpful post ..... Edited February 8, 2013 by KCwagon Link to comment Share on other sites More sharing options...
mwiener2 Posted February 8, 2013 Share Posted February 8, 2013 you can't even spell my name right when it's all over the place # 12,147 you gotta work to get numbers like this My Mods List (Updated 8/22/17) 2005 Outback FMT Running on Electrons Link to comment Share on other sites More sharing options...
KCwagon Posted February 8, 2013 Share Posted February 8, 2013 (edited) you can't even spell my name right when it's all over the place # 12,147 you gotta work to get numbers like this My Grandpa alway said "There is no I in TEAM..... but there is an I in WIENER" __________________________________________________________________________________ Anyway. I replaced the wiring from the power block to the FPCM, as well as the ground wire. I replaced the 16g wire that was there with 12 gauge wire. As a result I am reading 12.2 volts to the pump at 100% instead of 11.8 with the old wiring. It is obviously not ideal, but shows the significance of larger gauge wiring at these points. I am still running direct power through the control module and the factory wiring to the fuel pump. My NEW plan is to use the original power supply from the Fuel Pump Relay wire to power the FPCM as well as turn on the added Relay. The direct battery power running to the installed Relay will run directly (new wire) to the Fuel Pump. Hopefully this will allow the FPCM to work as it is intended (floating ground), as well power the pump with direct battery power w/o having to run direct power through the FPCM. Wish me luck. Oh, and mwiener, please feel free to comment on how this will not work. Edited February 8, 2013 by KCwagon Link to comment Share on other sites More sharing options...
mwiener2 Posted February 8, 2013 Share Posted February 8, 2013 Have I ever said any of this wouldn't work? No. I just think you have a lot of misguided, unneeded modding to attain a laughable goal. My Mods List (Updated 8/22/17) 2005 Outback FMT Running on Electrons Link to comment Share on other sites More sharing options...
Scooby2.5 Posted February 8, 2013 Share Posted February 8, 2013 If the Aero fixed the problem, you wouldn't be re-wiring your FPCM. If you go back a few pages you would know that putting in the Aeromotive pump in place of the AVO my AFR's dropped by over a point even at the low voltage that was running it. Seems the Aeromotive as seen from various tests is flowing more at the lower voltage. We then moved on to the wiring with the FPCM and the combo fixed the problem. So why are you suggesting a faulty Aeromotive pump? Link to comment Share on other sites More sharing options...
Scooby2.5 Posted February 8, 2013 Share Posted February 8, 2013 Have I ever said any of this wouldn't work? No. I just think you have a lot of misguided, unneeded modding to attain a laughable goal. Really? How so? Link to comment Share on other sites More sharing options...
mwiener2 Posted February 8, 2013 Share Posted February 8, 2013 That's another story altogether.... I've come across more bad ones than good ones. I refuse to sell them anymore. Under test conditions, they seem to work. In real world conditions, they don't, especially after some use. What measurable benefit are you getting by varying pump flow? Your modded motors will blow up long before you wear out the pump. The 0.02% gain in economy isn't it. The 5hp loss from hot fuel isn't it.... My Mods List (Updated 8/22/17) 2005 Outback FMT Running on Electrons Link to comment Share on other sites More sharing options...
Scooby2.5 Posted February 8, 2013 Share Posted February 8, 2013 (edited) I think there have been reports of walboro 255 failures and if I look around the web I rarely see Aeromotive stealth 340 issues. I also have seen numerous threads of 400 whp on E85 where walboro 255 is not enough flow. I wonder what your magic solution has been http://i241.photobucket.com/albums/ff228/ScottsAMSPics/FuelPumpflowchart1.jpg http://i241.photobucket.com/albums/ff228/ScottsAMSPics/Fuelpumpameragechart1.jpg Edited February 8, 2013 by Scooby2.5 Link to comment Share on other sites More sharing options...
mwiener2 Posted February 8, 2013 Share Posted February 8, 2013 (edited) I don't have a wideband and I'm probably a bit lean up top. But that's the joy of E85. Maybe try an Outback FPCM I dyno'd 436 awhp at 24psi boost. I was running 28-30psi a few months ago. Another shop owner up here has a 470 awhp 2.5rs that also has a walbro 255. I wouldn't suggest it to anyone, but it can do it. I have 3 aero pumps that would not hold proper fuel pressure in a car running 60psi base. Boost was 26, but one of the pumps dropped to 40psi at redline on a 7psi boost pull. This car has 10g wiring direct to the pump and would hold full voltage throughout a pull. All the pumps passed a flow test when removed from the car. Each pump performed properly for about a pull or two before failing. Aeromotive tech support claims cavitation on the impeller due to a negatively pressurized fuel tank. I say BS. A walbro 460 solved the problem. I had a Corvette with a 1000hp goal that had 2 aero's. First attempt the wiring supplied with the kit fried, killed one of the pumps. Put a new one in. Ran seperate 10g wire to each pump and fuel pressure would still drop off near redline when it was only making 600hp. Replaced with DW300's and amperage was down and fueling was up. I had similar experiences 3 years ago, let aeros sneak back in, but now they're out for good. Maybe think of the AEM320 as a middle ground pump. Edited February 8, 2013 by mwiener2 My Mods List (Updated 8/22/17) 2005 Outback FMT Running on Electrons Link to comment Share on other sites More sharing options...
doccrowley Posted February 8, 2013 Share Posted February 8, 2013 I had dropping fuel pressure troubles like you described. WOT on the dyno and pressure would drop, car would run lean. All voltage tests indicated in this thread never showed voltage drop from FPCM to the pump. Put a bunch of diagnostic money down the drain. It was determined that I had faulty o-rings in the fuel basket. Once that was remedied, fuel pressure was great at WOT. DW300. My walbro didn't survive after 2 months on E85. Still subscribed for future reference. Link to comment Share on other sites More sharing options...
Scooby2.5 Posted February 10, 2013 Share Posted February 10, 2013 (edited) My plan now is to wire it like z0rr0 did. I purchased the DW wiring kit, just to get the inline fuse, 12 ga wire, and relay and relay socket. Just to make it a more finished product. (IM OCD) Im going to run the DW kit from the battery to the pump positive lead. Switching the relay as we have been off the fuel pump relay feed to the module. Im going to leave the FPCM in place which is feeding the varying voltage to the negative pump lead. Should have full voltage direct to the pump from battery and varying negative lead from the module which should duty cycle the pump just like factory. At least going this route you will always have the batt/alt voltage to the pump and dont have to worry about a drop going through the wiring or the module. The negative lead out of the module to the pump seems to approximately be 0, 8v or 6v depending on the duty cycle requested. Will report back on how it works out. We will be doing mine and kcwagons car this way in the near future. Edited February 10, 2013 by Scooby2.5 Link to comment Share on other sites More sharing options...
Scooby2.5 Posted February 24, 2013 Share Posted February 24, 2013 (edited) Ok we worked on this again today and still have a weird issue so input is welcome. We wired kcwagons car today with direct batt voltage to the pump bypassing the factory wiring harness. Referencing ground we had 13.8 volts at the pump B+ We left the negative wire B- alone from the pump to the module. (the one that changes from 0,7,9) Now the problem we have is that if we reference ground to the B- at the pump we measure 1v in the first 7 seconds, giving us a difference accross the wires of 12.8 which is not enough If we reference that same wire at the MODULE output connector we get .2 volts. We are thinking we need to bypass the factory harness B- wire from the module to the pump like others did. I just cant figure out, why we get the B- reading .2v at the module output and 1v at the pump which is the other end of the same wire. (still not using a scope, I know I know) Its like we have more voltage AFTER it goes through the wire. WEIRD.......Any input?????? Edited February 24, 2013 by Scooby2.5 Link to comment Share on other sites More sharing options...
SeeeeeYa Posted February 25, 2013 Share Posted February 25, 2013 It's not DC? Link to comment Share on other sites More sharing options...
Scooby2.5 Posted February 25, 2013 Share Posted February 25, 2013 (edited) Yea I know, did you didn't see my parenthetical about not using a scope? Even so why the difference in measurements on one end of the wire vs the other end? Most others have been somewhat successful using a meter so that's what we have been using. Guess Ill dig my work scope out Im supposed to send it in soon for a recalibration anyway so might as well get it out. We just dont use them much anymore at work so I'm being lazy Edited February 25, 2013 by Scooby2.5 Link to comment Share on other sites More sharing options...
mwiener2 Posted February 25, 2013 Share Posted February 25, 2013 So what's the big deal about having a fuel pump that can be ramped down? My Mods List (Updated 8/22/17) 2005 Outback FMT Running on Electrons Link to comment Share on other sites More sharing options...
Scooby2.5 Posted February 25, 2013 Share Posted February 25, 2013 Not following you? Link to comment Share on other sites More sharing options...
mwiener2 Posted February 25, 2013 Share Posted February 25, 2013 You've spent months trying to rewire the stock FPCM so you can run the pump at 30, 60, 100%. You could have spent an hour or two hardwiring the pump and been done with it at 100% flow all the time. Why do you want variable pump so bad? This is part of pay to play. It doesn't always mean money. In this case it means you give up variable pump control so you can move the fuel you need. I'll say this again. The FPCM is an engineered circuit. It was designed for a pump that draws less than 10amps. Unless you re-engineer the circuit, it will never be stout enough to do what you are trying to do. My Mods List (Updated 8/22/17) 2005 Outback FMT Running on Electrons Link to comment Share on other sites More sharing options...
Scooby2.5 Posted February 25, 2013 Share Posted February 25, 2013 (edited) Cant say I disagree with what you said....... If there is a way to get it to work consistently without damaging the FPCM we will I might add the STI has larger wires, a different FPCM and it has 13.8 volts to the pump. Perfect! We are now duplicating that. Direct wire to the pump from Batt, Larger wire from the FPCM switched legg. Should work perfect. Otherwise we will do it the easy simple method, especially before we blow up a motor Watching AFR's closely Edited February 25, 2013 by Scooby2.5 Link to comment Share on other sites More sharing options...
integroid Posted February 25, 2013 Share Posted February 25, 2013 I honestly dont know how much this will have to do with it but the Legacy is also assembled in the US vs. the WRX and STI being assembled in Japan. Different sourced parts (wires) in the US vs Japan? Link to comment Share on other sites More sharing options...
frank_ster Posted February 25, 2013 Share Posted February 25, 2013 Ok we worked on this again today and still have a weird issue so input is welcome. We wired kcwagons car today with direct batt voltage to the pump bypassing the factory wiring harness. Referencing ground we had 13.8 volts at the pump B+ We left the negative wire B- alone from the pump to the module. (the one that changes from 0,7,9) Now the problem we have is that if we reference ground to the B- at the pump we measure 1v in the first 7 seconds, giving us a difference accross the wires of 12.8 which is not enough If we reference that same wire at the MODULE output connector we get .2 volts. We are thinking we need to bypass the factory harness B- wire from the module to the pump like others did. I just cant figure out, why we get the B- reading .2v at the module output and 1v at the pump which is the other end of the same wire. (still not using a scope, I know I know) Its like we have more voltage AFTER it goes through the wire. WEIRD.......Any input?????? well its dc but its pwm .the volt meter will read sort of an average, and the capacitance of the volt meter would bias up or down depending the the frequency, Now that's thinking out of the boxer! fyi all 05 + legacy's have built in code reader Link to comment Share on other sites More sharing options...
KCwagon Posted February 25, 2013 Share Posted February 25, 2013 I think we are going to replace the factory negative wire (from FP to FPCM) and see. It may be an issue of resistance running a large positive wire and a very small negative wire. We will report on the results. Link to comment Share on other sites More sharing options...
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