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Fuel pump control module


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No, I bypassed it. Been running at 100% duty cycle for almost 2yrs.(about 70k) with no issues.

 

IIRC, LGT as smaller gauge fuel pump & FPCM wires then the wrx & Sti's. Do to voltage drop off, FP never runs at 100% flow rate.

I ran a 10 gauge wire power & ground wires for the FP. And use a relay & the FPCM wires to turn on the FP when the key is turn to "RUN".

Thanks for the response hammer down. I didnt wait and wired mine last night. Good to know another lgt guy has done it first.

 

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That sucks, so running fuel pump at 66-100% all the time might overheat the wires then.

 

Do you know if the wires are thinner from the dash to FPCM too?

I doubt it will over heat them. The issue, as has been laid out in another thread, is that there is a significant volt drop with the wiring to the fpcm. Then there is more volt drop in the fpcm itself. Further more a small volt drop from fpcm to pump. After all that your pump is only getting 11.5v or something. So you never get the flow that the pump is rated for.

 

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I doubt it will over heat them. The issue, as has been laid out in another thread, is that there is a significant volt drop with the wiring to the fpcm. Then there is more volt drop in the fpcm itself. Further more a small volt drop from fpcm to pump. After all that your pump is only getting 11.5v or something. So you never get the flow that the pump is rated for.

 

Sent from my SM-G930P using Tapatalk

 

Sure that makes sense and is an issue with aftermarket pumps (since they are rated at certain flow at 13-14v). But with OEM pump, which was designed around all the voltage drops in mind, means it will flow the same still.

 

The big downside of forcing 100% all the time is, shorter pump life.

 

I'm on the stock pump but I think my FPCM is starting to go out, after reflash the FPCM is taking longer and longer to get to 33% at idle.

05 LGT 16G 14psi 290whp/30mpg

12 OBP Stock 130whp/27mpg@87 Oct

00 G20t GT28r 10psi 250whp/36mpg

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I'm on the stock pump but I think my FPCM is starting to go out, after reflash the FPCM is taking longer and longer to get to 33% at idle.

 

The FPCM duty circle is directly controlled by the ECU. The only feedback from it is if an error occurs (wiring short or module failure). There also isn't any fuel pressure feedback to the system, so the ECU has no idea if the module is going out. The FPCM is more or less a big transistor and some power filters, it's not some sort of truley intelligent device with it's own behavior. The only way to see if you're having issues would be the system leaning out at high demand.

 

NSFW: did you see any logic in the ECU that determines when to switch from 100% to the normal checks at startup? This may be more of a RomRaider forums question.

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Gotcha, I figured it might be a like a sticking relay or solenoid.

 

It's weird, I now have to wait 1 minute after reflash for FP duty to get down from 100% to 66% and another minute to 33%. Before it would go from 100% to 33% in under a minute.

05 LGT 16G 14psi 290whp/30mpg

12 OBP Stock 130whp/27mpg@87 Oct

00 G20t GT28r 10psi 250whp/36mpg

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Sure that makes sense and is an issue with aftermarket pumps (since they are rated at certain flow at 13-14v). But with OEM pump, which was designed around all the voltage drops in mind, means it will flow the same still.

 

The big downside of forcing 100% all the time is, shorter pump life.

 

That why I'm running the Deatschwerks 265 LPH In-Tank Fuel Pump (65c).

Mileage:331487 Retired/Sold

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NSFW: did you see any logic in the ECU that determines when to switch from 100% to the normal checks at startup? This may be more of a RomRaider forums question.

 

I didn't see anything like that but I wasn't looking. I can look into it though, I have some vacation time coming up.

 

It might be interesting to try reducing the duty-cycle thresholds to see if that makes any difference. I'm not real hopeful that it will, but it would be easy to try.

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...and you're not running E85 correct?

Correct, I'm running 93oct. E85 is not really available in my area.

 

Do you know what the flow rates are at say 10-11v? I found flow rates vs PSI at 13.5v but that's not helping :lol:

Nope, not a clue:rolleyes:

Mileage:331487 Retired/Sold

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  • 3 weeks later...

Incase anyone is trying to figure out the connector for the FPCM (to try and rewire it), I found it:http://prd.sws.co.jp/components/en/detail.php?number_s=60980156

 

You can buy this from your local Toyota dealer with PN 9098010862

 

It also has a mating connector if you want to rig up something PNP:http://prd.sws.co.jp/components/en/detail.php?number_s=60980154

 

Still working on sourcing the pins....

 

Pins: https://www.corsa-technic.com/item.php?item_id=814&category_id=184

Edited by utc_pyro
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  • 2 weeks later...

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