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Fuel pump control module


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What HP/TQ did you put to the wheels and what dyno was it on?

 

RomRaider's Road Dyno. 335whp/385wtq. E85. Stock catback.

Notes: RomRaider does not have a setting for the 08 spec.B so we used an STi profile to get the 6 spd. Obviously there are variations that were not accounted for so it is really only good for run-to-run comparisons with my car.

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  • 1 month later...
  • 3 weeks later...
I have a contact at DW that I will call on Tuesday and get more info about the voltage issue. If there is a problem I will see if this will this kit fix it and what price I can get this kit for. http://www.deatschwerks.com/fuel-pump-hardwire-kit Bryan
Racer X FMIC for '05-'09 LGTs, '08+ WRX and '10+ LGT,'14+ FXT, and '15+ WRX TMIC Racerxengineering.com
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Just a thought, maybe the fuel lines cannot keep up with the volume. There is a finite amout of fuel that will flow and any given pressure.

 

That's true about the flow. But, read post #48 you will see that his duty cycles went down when he ran a bypass.

Racer X FMIC for '05-'09 LGTs, '08+ WRX and '10+ LGT,'14+ FXT, and '15+ WRX TMIC Racerxengineering.com
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The hardwire kit will allow battery voltage to the FPM but even then it will not allow full voltage to the pump.

 

In our testing the FPM on the LGT/OBXT was limiting the output even if you bypassed the wiring harness and applied battery voltage direct.

 

The duty cycle did go down but not by enough, hence the reason for changing the module.

 

You could run battery voltage direct to the pump with the DW kit itsme posted but then you would have the pump running 100% DC all the time.

 

That kit is exactly what we did during the install. Inline fuse, relay etc. Great of DW to come out with it.

 

By the way the STI module I purchased bolted right into the stock location on my wagon in the left rear of the cargo area.

 

 

I also want to mention that I believe that unless you are approaching 380-400 WHP on E85 this will not be a factor to need this conversion.

 

E85 takes 30% more fuel and when you are pushing close to 400 with E85 the amount of needed fuel is greater hence the need for the pump to run at a higher voltage.

 

If my car were 385whp on pump gas I don't think you would see this issue as it would need less fuel. I could be wrong but thats what I think at this point.

 

I was trying to find other vehicles (LGT/OBXT) that were hitting close to this HP, with any turbo on E85, and seeing what the IDC was but haven't had much luck.

Edited by Scooby2.5
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That kit is just a wiring kit. I dont think it will work with the factory wiring at the pump since it is a PWM signal.

 

You can run the wiring direct to the pump and it will run 100% DC all the time.

 

You can run the kit direct to the FPM and the increase in wire size will allow more voltage to the FPM and cause the stock FPM to output higher voltage to the pump when the PW hits 100% DC.

 

You essentially bypass the factory wiring harness which is dropping the voltage as you go to the back of the car.

 

I thought I explained all this pretty well in previous posts? :confused:

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Just a thought, maybe the fuel lines cannot keep up with the volume. There is a finite amout of fuel that will flow and any given pressure.

 

Only fuel lines used were the ones coming from the tank to under the hood.

 

Everything under the hood was changed, ID1000 kit and custom fuel lines.

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I just got off the phone with DW and they said that their pumps performance is rated at the standard 13.4. And of the voltage is lower it will decrease the performance of the pump. He said the pump will work down to @ 8-9 volts and that lower voltage won't hurt the reliable of the pump. They are even willing to come on the site and answer questions. I think I will have them talk on a thread about there pump and then post a link for everyone to see. Let me know what you think. Bryan
Racer X FMIC for '05-'09 LGTs, '08+ WRX and '10+ LGT,'14+ FXT, and '15+ WRX TMIC Racerxengineering.com
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Im not really sure why the discussion on the pump......

 

Im sure everyones aftermarket pump, whether it be, Aeromotive, Walbro, AVO etc all are tested at battery + alt voltage which is generally 13.5 volts and above.

 

The problem with the legacy, near as we can tell, is you never get above 11.7 volts out of the fuel pump control module, even if a wire is direct to the module from the battery.

 

Not sure if you have read the whole thread or not but really the pump is not the issue its the voltage getting to the pump.

 

I replaced my AVO pump with an Aeromotive pump and it did not fix the problems discussed in this thread.

 

It wasn't until we discovered the voltage drop going to the module from the FPR and the low voltage out of the module to the pump.

 

Only After swapping in an STI module and running a wire from the battery to the module were we able to fix the issue.

 

See post 52

Edited by Scooby2.5
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This validates my solution, to maintain PWM control but also have hardwire override, activated via boost switch. So at the + & - wires from fuel pump module to pump, cut and intercept with DPDT relay. Have relay switched by boost pressure switch. When switched, relay directs power from fused thicker gauge wire direct from battery, through relay to fuel pump, back to relay and to ground (fuel pump module bypassed entirely). Could easily add a Boost-a-pump to the boost-switched circuit, so not only would you have BAP but you would have it on its own heavier gauge circuit. You may have to wire up a resistor to fool the fuel pump module, which would add some more complexity with second relay, but long story short the car would be all OEM-controlled while off boost, which would be nice!
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  • 2 weeks later...

Somewhat relevant to this thread, since I imagine people are trying to do something with the extra voltage, perhaps involving a bigger pump or either way more fuel.

http://forums.nasioc.com/forums/showthread.php?t=2300161

http://forums.nasioc.com/forums/showpost.php?p=36330515&postcount=5213

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Side note, some say the pump rebranded as a Walbro400 no likey E85.

Maybe that is why after running e85 for the last 6 months my car was getting harder and to start and my learning view was lean across the board. Now with my new DW 65c it starts quicker, runs smoother, and my learing view looks much better.

Edited by itsme
Racer X FMIC for '05-'09 LGTs, '08+ WRX and '10+ LGT,'14+ FXT, and '15+ WRX TMIC Racerxengineering.com
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  • 1 month later...
Older thread but have an interesting one related to this.....

 

Went to Cobb tuning back in 2009 and my car at 350whp 373wtq with an AVO380 AVO fuel pump and DW 850 injectors was at 100% duty cycle for some reason.

 

Just went to Cobb this week, I had changed regulator and orings in the tank but still had my 2-3 year old AVO pump in but now have Id1000's.

 

While at the beginning of tuning right when we got to 360whp 415wtq, still in the rich stages of the tune I was at 97% duty cycle on the ID1000's.

 

AFR's were in the 12.7 range when they should have been in the 10.5 range at the beginning of the tune.

 

 

I changed my pump to the Aeromotive Stealth in the parking lot and the AFR's dropped by a point immediately but I was still at 97% duty cycle on the injectors.

 

Through some trouble shooting and tearing of my interior apart to get to the fuel pump relay and the fuel pump control module/unit we found part of the problem.

 

My stock wiring harness was dropping almost 2 volts from the fuel pump relay to the fuel pump module at the back left of the car. It was causing the fuel pump to never get above about 11.7 volts coming out of the fuel pump module/unit.

 

We bypassed the wiring from the relay to the module and then were able to get 12.7 volts out of the module to the pump and the duty cycle of the injectors dropped to 80-85 % when the pump was at 100%

 

If we bypassed the fuel pump control module/unit altogether and had 14v battery/alt voltage it would drop the duty cycle of the injectors even more.

 

We are doing some more testing to find if the fuel pump module/unit is defective or not but it was interesting to see how the pump changed the AFR's as well as how I had a 2 volt drop in my wiring harness.

 

In my case the fuel pump control module/unit never allowed the pump to go above 11.75 volts on stock wiring and with external wiring it went to 12.7.

 

Stay tuned......

 

Help needed now. AF/r's of 15/1 to 19/1 and lucky the motor hasn't blown.

 

What came of this? Re-wire overide or conversion to STi FPCM only, or both??? I am confused.

 

DW300 fp 2 months old after I was told that my Walbro255 had died after only 3 months running e85.

 

850 side feeds, BNR hta68 running on E85 at approx 70%duty cycle. It goes massively lean above 4500rpm's after only 2 months on this tune and DW pump set-up.

 

Help.

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Help needed now. AF/r's of 15/1 to 19/1 and lucky the motor hasn't blown.

 

What came of this? Re-wire overide or conversion to STi FPCM only, or both??? I am confused.

 

DW300 fp 2 months old after I was told that my Walbro255 had died after only 3 months running e85.

 

850 side feeds, BNR hta68 running on E85 at approx 70%duty cycle. It goes massively lean above 4500rpm's after only 2 months on this tune and DW pump set-up.

 

Help.

 

I'll say it before someone else does: could be many things. Do you have a thread on this matter? Would like to follow. Your rate of fuel flow is not unusual, so the problem might not be electrical.

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Help needed now. AF/r's of 15/1 to 19/1 and lucky the motor hasn't blown.

 

What came of this? Re-wire overide or conversion to STi FPCM only, or both??? I am confused.

 

DW300 fp 2 months old after I was told that my Walbro255 had died after only 3 months running e85.

 

850 side feeds, BNR hta68 running on E85 at approx 70%duty cycle. It goes massively lean above 4500rpm's after only 2 months on this tune and DW pump set-up.

 

Help.

 

Could be your pump or your WB02 is dying.

 

Are you running at altitude? My 850 side feeds are in the high 90s IDC in the cold weather on E85 (FP HTA68 - 7cm) - no way your IDC s should be in the 70's.

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Just a thought, maybe the fuel lines cannot keep up with the volume. There is a finite amout of fuel that will flow and any given pressure.

 

Rao and I discussed this at length a while back. Stock fuel lines can flow more fuel than a single Walbro could ever possibly provide.

 

That all said, a buddy of mine runs two Aeromotive in-tanks with twin controllers. He did run -10 lines, but he is also shooting for 600+ on redneck-racegas.

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I'll say it before someone else does: could be many things. Do you have a thread on this matter? Would like to follow. Your rate of fuel flow is not unusual, so the problem might not be electrical.

Boost leak? Ooh, is your FPR line still connected to the manifold and FPR? Those things have a tendency to pop off if not properly secured. This would be my first guess.

 

If the tune was fine for 2 months and now the car runs like crap, it sounds like it isn't the tune and should be something mechanical. Then again, you were tuned the winter and now e85 is switching to summer blend which requires more fuel, so that could be it.

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