Fuel Issue
Thread Starter
Drifting
Joined: Sep 2005
Posts: 1,258
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From: Home Southern Maine
St. Jude Donor '08
Fuel Issue
Went to the dyno to wrap up my two stage install which I methodically installed over the last year. I added 42 # injectors for my dry stage, AR LT Headers, a racetronics fuel pump and hot wire kit, switched my LS1 intake for a LS6 intake, added a Shaner ported TB, been dabbling with EFI Live and the Custom Nitrous Operating system. I got the Custom Operating system working with the help of some of the EFI Live guru's and was looking forward to busting out 500 RWHP with my two stage Dry/Wet combo.
I did not get past the NA runs, up to about 3000 RPM pressure is 58 + or - 1 or 2, then at 100% TP fuel pressure drops to as low as 35 PSI, which drives up the AFR to 15.1-15.3 @ 6000 RPM, despite a commanded 12.6 AFR.
I am hoping its a simple issue like the fuel filter (probably 5k miles on it), but was wondering if others had similiar conditions and what the fix was.
I am offshore for a bunch of weeks and want to have the parts on hand for my limited time home, naturally I am starting with the Fuel Filter, but could it be the new pump?
Here is a screen from the log
I did not get past the NA runs, up to about 3000 RPM pressure is 58 + or - 1 or 2, then at 100% TP fuel pressure drops to as low as 35 PSI, which drives up the AFR to 15.1-15.3 @ 6000 RPM, despite a commanded 12.6 AFR.
I am hoping its a simple issue like the fuel filter (probably 5k miles on it), but was wondering if others had similiar conditions and what the fix was.
I am offshore for a bunch of weeks and want to have the parts on hand for my limited time home, naturally I am starting with the Fuel Filter, but could it be the new pump?
Here is a screen from the log
and drinking 
to keep from going 
over here 
Collections Hold
Joined: May 2003
Posts: 3,520
Likes: 2
From: Tacoma WA
Beer, I can't tell what's what on your screen shot? is the green line the fuel pressure?
When was the last time you changed the filter? I changed mine out when I put the racetronics in. Do you have a drop in pressure n/a? or at least more than before? Seems this just cropped up as you had things dialed in before right?
Robert
When was the last time you changed the filter? I changed mine out when I put the racetronics in. Do you have a drop in pressure n/a? or at least more than before? Seems this just cropped up as you had things dialed in before right?
Robert
Thread Starter
Drifting
Joined: Sep 2005
Posts: 1,258
Likes: 0
From: Home Southern Maine
St. Jude Donor '08
Yellow is Throttle Position...Light Blue is RPM, Green is Fuel Pressure, magenta is AFR.
Fuel pressure is good 58 PSi to 3000 RPM at part throttle. Go WOT and it drops to 35-40 PSI and the AFR climbs to 15.1-15.3 @ 6000 RPM.
The fuel filter probably has 4000-5000 Miles on it.
This is NA, did not spray as it was a show stopper at the dyno.
The Racetronics is new, LOL I bought it to ensure no fuel issues...
Fuel pressure is good 58 PSi to 3000 RPM at part throttle. Go WOT and it drops to 35-40 PSI and the AFR climbs to 15.1-15.3 @ 6000 RPM.
The fuel filter probably has 4000-5000 Miles on it.
This is NA, did not spray as it was a show stopper at the dyno.
The Racetronics is new, LOL I bought it to ensure no fuel issues...
Last edited by Beer99C5@FastbirdPerf.com; May 21, 2007 at 02:25 AM.
