Jump to content

Fuel pump PWM controller


Recommended Posts

That drawing looks a bit wrong?  It looks like they are using the FPC to pulse a mechanical relay?  

In the factory setup, Pin 10 is high current 12V from the fuel pump relay.  The fuel pump connects directly to pin 6 & 7.

Pin 8 is the PWM signal, connect that to any Aux output.  Pin 9 is not needed, it is just a "pump is running" signal from the FPC back to the ecu.

 

A9izggv.png

Link to post
Share on other sites

I think you are correct, my understanding from the article is the f/p controler has a voltage step down at full load from memory I think it said aprox 10.9v supply, 

The article said the use of the relay was to take a direct feed from the battery to the fuel pump pulsing the relay via ground. 

Would a solid state relay do the same thing with out the use of the f/p controller?

Link to post
Share on other sites

I dont know specifically with the subaru controller as I have never tested one, but one advantage some of the common fuel pump controllers have over just a SSR is the pump PWM is done at very high frequency.  Ie, the ecu PWM signal to the FPC is say 80Hz, but the PWM output to the pump from the FPC is 20000Hz or similar.  They also typically have a well designed snubber circuit.  The result is quieter operation and a broader control range.

Link to post
Share on other sites

Replace the subaru controller with a Jag XJ controller.

That's what I ran on my subaru before I went brushless. I also ran it with and without a cheap amazon voltage booster/regulator up to 16V for more flow.

They're easy to get under $100 and I can get you connectors if you're in the US.

Link to post
Share on other sites
2 hours ago, barge said:

Replace the subaru controller with a Jag XJ controller.

That's what I ran on my subaru before I went brushless. I also ran it with and without a cheap amazon voltage booster/regulator up to 16V for more flow.

They're easy to get under $100 and I can get you connectors if you're in the US.

Is there a particular advantage to the Jag unit over the Subaru? I can get the Subaru one for £12 on eBay UK.  I don't know enough about these units to know what makes one better than the other...

Link to post
Share on other sites
On 2/17/2021 at 1:48 AM, barge said:

Replace the subaru controller with a Jag XJ controller.

That's what I ran on my subaru before I went brushless. I also ran it with and without a cheap amazon voltage booster/regulator up to 16V for more flow.

They're easy to get under $100 and I can get you connectors if you're in the US.

Cheers for the jag controller info.. Do you have a link to the voltage booster you used handy 

Link to post
Share on other sites
  • 2 weeks later...

Dan, did you manage to get this setup working with the subaru PWM controller?  I've done a bit digging and apparatly the PWM signal they use is 5v not 12v.  Anyone know how you can reduce the ecu's 12v aux outputs down to 5v?  Electronics baffle me,  I'm assuming the plug in G4X units for impreza's must have some sort of circuitry built in to do this.

Link to post
Share on other sites
7 minutes ago, ellisd1984 said:

Dan, did you manage to get this setup working with the subaru PWM controller?  I've done a bit digging and apparatly the PWM signal they use is 5v not 12v.  Anyone know how you can reduce the ecu's 12v aux outputs down to 5v?  Electronics baffle me,  I'm assuming the plug in G4X units for impreza's must have some sort of circuitry built in to do this.

I've gone with the jag controller insteed 

Link to post
Share on other sites

The subaru controllers actually work fine with a normal aux (12V), but the other option is use an ignition output (6V) or a 5V zener diode connected inline with your aux. 

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...