Fuel pump control module

there's a factory fuel temp sensor

 

back in the gas tank IIRC, which would show average--not peak (rail)--temp. Would get you pretty close though if one has kept their fuel system return-style (series, parallel, not quad-port distribution block like many aftermarket rail vendors do.

 

Also, was thinking how easy it would be to decouple the rails (aftermarket) from the engine, with either a low-heat-conductivity-material bracket, or just some decoupling washers made of silicone or urethane or nylon or whatever. T1 advertised this on their rails for the GT-R, though they did not address the bolts still coupling the rails to the engine...

Edited March 2, 2013 by ClimberD@HexMods

http://www.moroso.com/catalog/categorydisplay.asp?catcode=32030

Tested to 25 psi, and not recommended for high-pressure fuel systems. But looks like it would definitely cool-down a fuel stream.

Put it in the return line

^ uh ... nevermind

you'll eventually cool the whole tank down

but the tank its self is a giant radiator. the tank will want to be what ever the ambient temp is. + the heat from the engine that is blown under and the heat from exhaust.

^My thoughts exactly. Don't see much benefit to cooling the fuel down post-delivery to the fuel rails.

 

So S2.5 and KC, where do things stand now?

Repalced the negative wire from the pump to the FPCM with 12 gauge wire. I have 13.2 volts to the pump at 100% - measured with a handheld volt meter. I have it broken down progressively from stock to where I am at now. All reading were taken at the pump with the same volt meter at 100% pump duty cycle

 

STOCK - 11.5 volts

STI FPCM - 11.8 volts

STI FPCM, 12g power to pump - 12.7 volts

STI FPCM, 12g power to pump, 12g ground to FPCM - 13.2 volts

On a side note - I replaced that damn factory Fuel pressure regulator with an aftermarket FPR this evening - resulting in AFR's that are more favorable. In hindsite, I believe my fueling issues were the factory FPR this whole time Oh well, the pump should be happier at 13.2 volts anyway.

mwiener2 is gonna have a feild day with this one !

He may but shouldn't. On E85 with Shawn's FMIC and an 18G his car probably would have been running out of fuel if he didn't have the voltage up to proper specs.

 

I changed my FPR as well but with out the voltage fix I would have still run out of fuel.

 

Really both things need to be done.

 

I think the ONLY thing we have all been differing on is whether or not to use the FPCM or run the pump all the time.

 

As of right now Shawn is still running the FPCM so when he says 100% he means through the FPCM not direct wire and pump running 100% all the time.

 

So far those that have changed the wiring and the module have gotten correct voltage like an STi at the pump and if you change the stupid 05 FPR its even better.

 

The later LGTs had the FPR like the STI

Yes, I should have specified that I am still using the FPCM to modulate the pump duty cycles via the FPCM GROUND wire. I used the factory power from the Fuel pump relay to power both the FPCM and the added RELAY (on/off switch for battery power).

 

Overall, I think it is worth addressing the voltage issues in our cars, especially if you are planning to run E85.

^^ when I was losing fuel pressure at WOT it was o-rings in the fuel basket.

 

Glad you found the source of trouble for your af/r's and hope it stays great from now on!

^^ when I was losing fuel pressure at WOT it was o-rings in the fuel basket.

 

Glad you found the source of trouble for your af/r's and hope it stays great from now on!

 

Thanks, me too.

 

I was getting ready to pull the basket, but was pretty sure it was not the issue, because changing the fuel pumps had no effect on my AFR's. I have spent about a year tracking down my issue. I guess it gave me something to do, right?

 

Over the past year I changed the:

 

1) Fuel Pump - from a Walbro to a 65C

2) Fuel Pressure regulator - I replaced the actual regulator, but left the rest of that mess in the factory bracket, which I am assuming was my issue. (The thing is a mess and am not sure if there is a check valve in there that could be leaking or not allowing the FPR to hold pressure ??? (Wiener) There is also a return hose that I am not sure of the exact function....)

3) Re-wired pump

4) Replaced the O2 sensors

5) Replaced the Turbo inlet with an aftermarket inlet

How many different years of STI FPCMs plug in to our 05 legacies? What kind of FPR are you guys running?

How many different years of STI FPCMs plug in to our 05 legacies? What kind of FPR are you guys running?

 

I believe 05-07 FPCM will work. For me, I saw greater results by rewiring/replacing the factory small gauge wiring to and from the pump. I am also running direct power to the pump and bypassing the FPCM. The FPCM controls the Fuel Pump via the ground wire (pulse width modulation). I am getting ready to install an Aeromotive Fuel pressure regulator. Lots of folks are running the Aeromotive FPR with good results.

I've been running my 04 STI FPCM re-wire project now with e85 (e70 right now) for about 4 months and is working great. Granted I don't drive the car everyday. My tuner was really shocked that my car's fueling problems went away after this mod. So I'm very grateful for this thread! I'm running a DW65c so I'm not pulling the amps that some of the bigger fuel pumps would pull. So I don't think I'm over taxing the FPCM.

You are right, the 04 would work as well. Our cars are challenging in the fueling department. I only saw a .4 volt increase with an STI FPCM. Some people are reporting larger gains.

 

I am only seeing 13.2 volts at 100% FP duty cycle, with 12g wiring, STI FPCM, and the pump wired directly to battery power. I am retaining the fuel pump duty cycle through the FPCM via the negative wire. The only thing I can do now is to ground the pump and skip the FPCM altogether. Fueling seems to be fine now though.

I am only seeing 13.2 volts at 100% FP duty cycle, with 12g wiring, STI FPCM, and the pump wired directly to battery power. I am retaining the fuel pump duty cycle through the FPCM via the negative wire.

 

I think you did this already, but just wanted to be sure... Did you take the FPCM chassis ground (I think it's pin #5 on one edge of the connector) and run a heavy gauge wire from the FPCM directly to the chassis?

I think you did this already, but just wanted to be sure... Did you take the FPCM chassis ground (I think it's pin #5 on one edge of the connector) and run a heavy gauge wire from the FPCM directly to the chassis?

 

Yes.

Hello, this is my first post on lagacy Gt. I was linked hear by a friend as I have bypassed my fuel pump controller on my 05 forester XT. I haven't read the entire thread yet, only the first 6 or so pages, but so far I am very interested in the findings.

 

I thought I would also link my method hear as it may help some of you. I did mine as I suspected the FPCM would have this sort of effect, and also as I suspected it would cause variances with flow, which in turn would also affect the accuracy of adjusting in my aftermarket fuel pressure regulator. After reading this, I might also add a thicker power and earth feed to my existing mod.

 

The Mod can be viewed here on the link below at Ozfoz.

 

http://ozfoz.com/forum/viewtopic.php?f=29&t=38767

Looks like DCCDpro the makers of the DCCD controller used in many 6 speed swaps has come out with a fuel pump control module.

 

http://dccdpro.com/main/?p=309

 

http://dccdpro.com/zcart/index.php?main_page=product_info&cPath=3&products_id=6

Edited May 25, 2013 by Scooby2.5

Install Guide.....

 

http://dccdpro.com/main/wp-content/downloads/FUELPro%20Guide.pdf

Does anyone know what the inputs the fuel pump control unit is receiving from the ECU?

I'm going to be ordering the DCCD pro controller, and figuring out what the heck it's doing.

It looks ridiculously cheap though, either a buck-boosting circuit, or a 555 timer doing the PWM.

Doesn't look like it would hold up to 55a to me at all. Looking into it more, i'll update when I receive it.

-CB

Edited June 5, 2013 by bettner12

Are you going to try and control an A1000 with this guy?