Aracheon Posted January 25, 2013 Share Posted January 25, 2013 and why is a sti control module better? are they not both commanded by the ecm? Specifically, the 04 STi FPCM. The internal wiring is nearly 2x larger. I noticed significantly less voltage drop across the STi unit. This is all detailed in earlier posts in the thread, if you care to read it. Link to comment Share on other sites More sharing options...
frank_ster Posted January 25, 2013 Share Posted January 25, 2013 oh i'm sory its been so long ago. 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...
mwiener2 Posted January 25, 2013 Share Posted January 25, 2013 So it's less voltage drop but there is still drop? Sounds like a band-aid to me My Mods List (Updated 8/22/17) 2005 Outback FMT Running on Electrons Link to comment Share on other sites More sharing options...
Drew888 Posted January 25, 2013 Share Posted January 25, 2013 100% idc to high 80's because of the voltage is significant enough to investigate. It isn't a problem being fixed so much as an improvement. Left alone we'd all just deal with it as is. [URL="http://legacygt.com/forums/vbpicgallery.php?do=view&g=1586"VbGallery/URL] Link to comment Share on other sites More sharing options...
Aracheon Posted January 25, 2013 Share Posted January 25, 2013 So it's less voltage drop but there is still drop? Sounds like a band-aid to me The voltage drop across the OEM unit was around 1.5v. It was around 1.0v on the first STi unit I bought. It was 0.1v on the second unit I bought. The second unit completely eliminated my fuel pressure problem, as the pump was finally seeing the current it needed to keep up. Link to comment Share on other sites More sharing options...
KCwagon Posted January 25, 2013 Share Posted January 25, 2013 (edited) So it's less voltage drop but there is still drop? Sounds like a band-aid to me Unless you wan't to run w/o a Fuel Pump Control Module altogether you can't avoid a voltage drop. The wiring in the STI unit is significantly larger compared to the wiring in the LGT unit.. Combined with using wired power from the battery, it is a great deal better than the factory configuration. I am not sure why you consider this a "band-aid". Edited February 3, 2013 by KCwagon Link to comment Share on other sites More sharing options...
Scooby2.5 Posted January 25, 2013 Share Posted January 25, 2013 It's because AGAIN the last few posters have not READ THE THREAD!!!!! Sounds like a "band aid" Read through the thread you lazy people, good grief! If this keeps up ill see if bosco can close it up Link to comment Share on other sites More sharing options...
Scooby2.5 Posted January 25, 2013 Share Posted January 25, 2013 oh i'm sory its been so long ago. What's that have to do with anything? Are you saying you don't like historical fact? Link to comment Share on other sites More sharing options...
Scooby2.5 Posted January 25, 2013 Share Posted January 25, 2013 (edited) i didnt read the whole thread. Edited January 25, 2013 by Scooby2.5 Link to comment Share on other sites More sharing options...
frank_ster Posted January 25, 2013 Share Posted January 25, 2013 Meh 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 3, 2013 Share Posted February 3, 2013 (edited) Yep! Turned out that the first FPCM I bought was bunk. Bought a second replacement and the problems suddenly went away. Sent from my ADR6400L using Tapatalk I may be having problems with mine. Mine is re-wired, has an STI FPCM, and I am still seeing 11.9 volts to the pump Edited February 3, 2013 by KCwagon Link to comment Share on other sites More sharing options...
mwiener2 Posted February 3, 2013 Share Posted February 3, 2013 O, your band aid stopped working? Time to hardwire 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 3, 2013 Share Posted February 3, 2013 O, your band aid stopped working? Time to hardwire it. I think someone used recently the word insolent to describe you in another thread. Definition of INSOLENT since I am sure you dont know the definition: 1 : insultingly contemptuous in speech or conduct : overbearing 2 : exhibiting boldness or effrontery : impudent effrontery: a very confident attitude or way of behaving that is shocking or rude Effrontery describes the attitude of a person who does something very boldly and without shame even though it is wrong or offensive in some way. If the shoe fits........ I think you work in a shop and do have some knowledge BUT I WOULD NEVER BRING A CAR TO YOUR SHOP If you read through the thread you will find out why we do not want to hardwire the pump for 100 DC all the time. If you have nothing CONSTRUCTIVE to add to this stickied thread GO AWAY! Link to comment Share on other sites More sharing options...
KCwagon Posted February 3, 2013 Share Posted February 3, 2013 (edited) O, your band aid stopped working? Time to hardwire it. Oh Weiner..stop being a dick I just bought another STI module to help troubleshoot. I will dig into it this week and report. Thanks to everyone who has done the homework on this one. Edited February 3, 2013 by KCwagon Link to comment Share on other sites More sharing options...
mwiener2 Posted February 3, 2013 Share Posted February 3, 2013 (edited) The modules were designed for a certain amp draw. You are putting in pumps that require more amps. The modules can't keep up. Big surprise. You need to find an aftermarket fuel pump controller (there aren't any at an affordable price) or you need to modify the stock one to handle higher current. Unless an electrical engineer decides to take this on in his free time, you guys are chasing your tails... with BANDAIDS edit: Fuelabs makes some pump / regulator combos that would solve all your issues properly. But you'll have to pay for it. Edited February 3, 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...
frank_ster Posted February 4, 2013 Share Posted February 4, 2013 automation direct solid state relay? does the fpcm get a pwm input? 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...
Aracheon Posted February 4, 2013 Share Posted February 4, 2013 I may be having problems with mine. Mine is re-wired, has an STI FPCM, and I am still seeing 11.9 volts to the pump They don't last forever, evidently. Since it's a cheap and easy replacement, slapping another FPCM in there would be what I'd try next. (Assuming you don't want to plunk down a few Benjamins to replace it with an aftermarket unit.) Link to comment Share on other sites More sharing options...
Scooby2.5 Posted February 4, 2013 Share Posted February 4, 2013 I totally agree with weiner's last post about the current draw, IMHO it can be somewhat fixed with the proper run size of wire, which we did not do from the FPCM to the Pump. Knock on wood Mine has bee running fine for almost a year no problems. Many an STI (which has larger wire) has run an aftermarket fuel pump with the stock wiring and stock STI FPCM and had no issues. I think if you get the voltage up to the FPCM with the direct wire off a relay and run larger wire to the Pump from the module like aracheon did it will be fine. Running larger wire to my PUMP this week. I do think the 10 guage wire aeromotive suggests may be a bit over kill so I am going to go a bit smaller and see how it goes. If not Ill get the aftermarket one. By the way as you said it is a cheap replacement using the 04-05 STI one if you BUY IT USED. If you dont get it used for some reason as uncle mat pointed out the 04-05 one is 300 bucks or more. I am guessing some larger more expensive circuitry is being used in the older ones and now they have went to a more cheaply made one. Mine is currently at 13.4 volts at the pump but with the next wire change it should be more which should lower the current draw. Ill try to get some more specs on the aeromotive and see what the current draw is at 13.5 volts and see what guage wire is actually necessary. Link to comment Share on other sites More sharing options...
Scooby2.5 Posted February 4, 2013 Share Posted February 4, 2013 (edited) Sorry for being so harsh. The fpcm is designed for a pump that never draws more than 20a because that's the fuse Subaru put in there. Evan at 15a, you guys have found undersized wiring. In my opinion, anything larger than 300l/h should have dedicated wiring and the only way to cycle it world be to get an aftermarket controller. You guys have over stressed controllers that could fail at any time. The modules were designed for a certain amp draw. You are putting in pumps that require more amps. The modules can't keep up. Big surprise. You need to find an aftermarket fuel pump controller (there aren't any at an affordable price) or you need to modify the stock one to handle higher current. Unless an electrical engineer decides to take this on in his free time, you guys are chasing your tails... with BANDAIDS edit: Fuelabs makes some pump / regulator combos that would solve all your issues properly. But you'll have to pay for it. Ok so you have pointed this out 2 times and I already responded before but I will give it a go again. I even talked to an electrical engineer with the company I work for today (Toshiba Medical Systems) so for whats its worth. I am the only one that I know of IN THIS THREAD so far running the AEROMOTIVE 340 pump with the STI module and pushing it hard on E85. It is advertised as a low current pump by a 340LPH pump standards. Its MAXIMUM current draw is 19 AMPS. "Considering the wiring requirements for a single 340 Stealth pump, installing multiple pumps on a single hanger will require serious, heavy duty electrical bulkheads, along with the same level of external wiring, relay(s) and fuses/breakers. Looking at the flow and current draw chart on page 2 of the 340 Stealth Pump instructions, you see that each pump is drawing 15 amps at 60 PSI and 13.5 Volts. Two pumps draw 30 amps, 3 pumps 45 amps. As pressures go higher, so goes current draw, with a peak of 19 amps per pump at 90 PSI pressure." The pumps like the DW 65C draw WAY less AMPS than the Aeromotive at maximum flow. "Connector Terminal Spade pos/neg Min Voltage Input 6 volts Max Voltage Input 18 volts Current Draw (40 psi) 12 amps (13.5v) Current Draw (80 psi) 15 amps (13.5v)" So basically what I am showing by the pump MFG data is that we are not EVER pulling more than about 15 amps with either of these pumps. At 43 PSI base pressure and 20 PSI of boost we are running 63 PSI which would be approximately 15 amps on the aeromoitve and about 13.5-14 amps on the DW 65c. I would think a 20 AMP circuit with updated wiring should be able to handle that. Wouldnt you???? Now with all that being said, I looked at the fuse for the fuel pump on a legacy and it is a 15 amp fuse not a 20 amp. I am not sure what the amperage is of the fuse in an STI, anybody know if its 15 or 20???? Edited February 4, 2013 by Scooby2.5 Link to comment Share on other sites More sharing options...
mwiener2 Posted February 4, 2013 Share Posted February 4, 2013 I usually see around 17amps on an Aeromotive 340 as measured by an amp clamp. I also rarely see Aeromotive 340's live up to their spec sheet. I'm not going to be using them anymore for customers because of my experiences with them over the last 5 years, the final one being last week. I'm pretty sure lots of people have 340's in legacy's as well. They're just not on here. Yes, everything you guys are doing is HELPING. But it's not fixing the problem. The problem is that the FPCM is not designed to run a pump larger than stock and unless you redesign the module, you'll always have a problem. 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 4, 2013 Share Posted February 4, 2013 17 amps at what pressure? What was the problems you are having with the Aeromotive in general as well as last week? I will say I did have an issue with my first Aeromotive in that the check valve in the pump went bad and was draining the fuel back to the tank at key off so fast it was hard to restart. Aeromotive noted my pump flowed more than they had seen when it was tested and I am sure it was because the checkvalve was not restricting it. Ive seen people remove the valve to get more flow. I didnt care because it flows enough for my setup and the check valve is nice for priming and keeping pressure up for a while like its supposed to on a daily driver so it starts easy. Link to comment Share on other sites More sharing options...
KCwagon Posted February 4, 2013 Share Posted February 4, 2013 The modules were designed for a certain amp draw. You are putting in pumps that require more amps. The modules can't keep up. Big surprise. You need to find an aftermarket fuel pump controller (there aren't any at an affordable price) or you need to modify the stock one to handle higher current. Unless an electrical engineer decides to take this on in his free time, you guys are chasing your tails... with BANDAIDS edit: Fuelabs makes some pump / regulator combos that would solve all your issues properly. But you'll have to pay for it. I sustained a cut today on my hand while replacing my FPCM. Mweiner, you will be glad to hear that I had to use a Band-aid. I guess you were right after all.. Link to comment Share on other sites More sharing options...
SeeeeeYa Posted February 5, 2013 Share Posted February 5, 2013 i am not sure what the amperage is of the fuse in an sti, anybody know if its 15 or 20???? 15 Link to comment Share on other sites More sharing options...
mwiener2 Posted February 5, 2013 Share Posted February 5, 2013 17amps at 43psi. 18-19 at 60psi. My Mods List (Updated 8/22/17) 2005 Outback FMT Running on Electrons Link to comment Share on other sites More sharing options...
Aracheon Posted February 5, 2013 Share Posted February 5, 2013 Mike, what are you using for fuel pump control? Link to comment Share on other sites More sharing options...
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