Can I tune fuel pressure w/S-AFC?

Subscribe
May 14, 2003 | 11:34 AM
  #1  
I have the walbro fuel pump installed on my 99 S/C max and i'm pretty sure its running rich. I want to know if i can lower my fuel pressure with just the S-AFC? Instead of buying both the SARD FPR and S-AFC, if not, then would I be ok running just the S-AFC for a little. I really want to dyno tune my car but money is a little tight and I'd rather just by the S-AFC for now. Thanks for any help
Reply
May 14, 2003 | 11:41 AM
  #2  
Nope, the S-AFC won't affect fuel pressure. You can use the SAFC to help adjust your a/f ratio, but you must spend time on the dyno to tune it. The afc adjust the amount of fuel being delivered, not the pressure it is delivered at. An aftermarket fpr would be a lot cheaper than buying a safc and the associated dyno time. Hope this helps.
Reply
May 14, 2003 | 11:48 AM
  #3  
Yes that definitely helps, thanks
Reply
May 14, 2003 | 12:43 PM
  #4  
No you use the SAFC to add fuel(richen fuel mixture) or subtract(lean) fuel mixture. You use the Vortech FMU to adjust fuel pressure by changing discs, or you can adjust it with that SARD or Cartech FMU.
Reply
May 14, 2003 | 01:06 PM
  #5  
Quote:
Originally posted by JAY25
No you use the SAFC to add fuel(richen fuel mixture) or subtract(lean) fuel mixture. You use the Vortech FMU to adjust fuel pressure by changing discs, or you can adjust it with that SARD or Cartech FMU.
Just a footnote to add to what you're correctly saying, the SAFC adds or subtracts fuel by controlling injector pulse width.

A question I have (sorry to ***** up your post, but it's related) is does the SAFC affect afr during partial throttle acceleration when the ecu is in closed loop mode and is making adjustments based on oxygen sensor input? I'm thinking it does, but I remember reading about some doubts about this.
Reply
May 14, 2003 | 07:14 PM
  #6  
Nope. The SAFC can only be set to work above 50% throttle, or else the ECU will eventually cancel it out. Kinda sucks.
Reply
May 15, 2003 | 08:02 PM
  #7  
39% throttle
Reply
May 16, 2003 | 05:57 AM
  #8  
Quote:
Originally posted by delio
39% throttle
Not sure what you're saying here.
Reply
May 16, 2003 | 06:00 AM
  #9  
Quote:
Originally posted by Stephen Max


Not sure what you're saying here.
The SAFC should be set to work above 39% throttle, not necessarily 50%.
Reply
May 16, 2003 | 06:50 AM
  #10  
Quote:
Originally posted by mzmtg


The SAFC should be set to work above 39% throttle, not necessarily 50%.
Oh, that's right, I forgot. I had a senior citizen moment, I guess.
Reply
Subscribe