Question on AFPR setting???
Thread Starter
Intermediate
Joined: May 2003
Posts: 42
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From: LaCrosse WI
Question on AFPR setting???
Restoring our 95 LT1 corvette and upgraded to 28 pound injectors. Purchased an Aeromotive adjustable fuel pressure regulator from Summit. This is probably an obvious question, but what do I set the AFPR at (28#)?
Thanks! :hurray:
[Modified by nlstrand, 12:47 AM 2/7/2004]
Thanks! :hurray:
[Modified by nlstrand, 12:47 AM 2/7/2004]
Team Owner
Joined: Dec 2000
Posts: 90,675
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From: SE NY
Cruise-In II Veteran
Re: Question on AFPR setting??? (nlstrand)
Measure our current fuel pressure and, assuming you have 24lb/hr injectors set the pressure to SQRT(24/28) * (current pressure). That assumes the both injectors are rated at the same pressure.
Thread Starter
Intermediate
Joined: May 2003
Posts: 42
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From: LaCrosse WI
Re: Question on AFPR setting??? (nlstrand)
Hmmm,
Threw out stock injectors (24 or 26 pound?) as two were malfunctioning. Decided to buy and have installed new 28# injectors and threw the stock fuel pressure regulator for Aeromotive replacement as hoping to do future upgrades. Still have old injectors and regulator. What can I expect (any problems) with these new injectors in terms of performance? Will set AFPR at 44-46# and hope all is well! :confused:
Threw out stock injectors (24 or 26 pound?) as two were malfunctioning. Decided to buy and have installed new 28# injectors and threw the stock fuel pressure regulator for Aeromotive replacement as hoping to do future upgrades. Still have old injectors and regulator. What can I expect (any problems) with these new injectors in terms of performance? Will set AFPR at 44-46# and hope all is well! :confused:
Burning Brakes
Joined: Nov 2000
Posts: 1,012
Likes: 1
From: Bowie MD
Re: Question on AFPR setting??? (nlstrand)
Let me tell you my story of runnin rich. You might be able to smell it at tail pipe. Car will bog down alot. And worst of all, you will burn up the catylitic convertor, so that you will not pass emmisiions inspection. I wish I had tuned mine with an air fuel meter, before I started loosin money on parts. (it was a new cat too). The opposite is what I saw at the dyno shop in Virginia off I-95. A guy self tuned his car at the track for the fastest times in the quarter. He leaned it out so far, that he burnt a piston, and then had a dead motor. But he was quick that short day, I am sure. You are also measuring the pressure with the rubber vacum hose unplugged to the AFPR, and the vacumn leak plugged. This simulates Wide-Open-Throttle position. Some use the pressure guage with a hose and duct tape the gauge to the windshield, to see rear WOT pressure. Hope that isnt confusing enough.
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Intermediate
Joined: Nov 2003
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Re: Question on AFPR setting???
Q:1, What pressure adj./setting for the (new)28#injectors.
A: Your stock units are 22#(Multi Tech). I suggest ya get the pressure settings from the party(s) that recommended/guided you to the higher flow-rated injectors and adustable fuel pressure regulator.
Q:2, Fuel quantity indicating zero (tank full).
A: Check for "open" circuit from dash to fuel tank terminal.If this cks. OK,replace "sending" unit (inside Tank).
BTW,I replaced my cloged/stopped-up stock injectors with the oft recomended Ford 24#, keeping stock FPR.No mixture issues. She runs great/normal.
A: Your stock units are 22#(Multi Tech). I suggest ya get the pressure settings from the party(s) that recommended/guided you to the higher flow-rated injectors and adustable fuel pressure regulator.
Q:2, Fuel quantity indicating zero (tank full).
A: Check for "open" circuit from dash to fuel tank terminal.If this cks. OK,replace "sending" unit (inside Tank).
BTW,I replaced my cloged/stopped-up stock injectors with the oft recomended Ford 24#, keeping stock FPR.No mixture issues. She runs great/normal.
Drifting
Joined: Aug 2000
Posts: 1,521
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From: West Islip New York
Re: Question on AFPR setting??? (nlstrand)
I don't know what size you had originally, you mentioned 24-26, but depending on your future plans, you may have bought too large an injector.
To adjust the AFPR start out with the stock pressure and then add a pound or so to make up for the larger injector. It all about spray pattern. Too many people buy larger injectors and then believe lowering the pressure will compensate for that. All that does is ruin the spray pattern.
Did you buy injectors rated at 43 psi ?
To adjust the AFPR start out with the stock pressure and then add a pound or so to make up for the larger injector. It all about spray pattern. Too many people buy larger injectors and then believe lowering the pressure will compensate for that. All that does is ruin the spray pattern.
Did you buy injectors rated at 43 psi ?
