EFI adj. fuel press.?

95/GT/5.0 · 08-12-2003, 10:48 PM

I have a stock 5.0L with 3.27 ratio diff.,tremec tko,underdrives ;ported cobra intake,65mm trottle body,73mm mass air calibrated for 19lb inj.,cold air intake,155 fuel pump,and paxton adjustable fuel press.regulator.My question is - WHAT SHOULD THE FUEL PRESSURE BE SET AT WITH THIS SET UP?DO I NEED A AIR / FUEL RATIO GAUGE TO SET FUEL PRESS. CORRECTLY??

TMASTER · 08-12-2003, 11:53 PM

Run 40psi with the vaccum line off, that should be right on.
the stock regualtor is to high fuel pressure.

Dark_5.0 · 08-13-2003, 09:42 AM

IMO you should be running 38-40 psi WOT fuel pressure which is when you set the fuel pressure with the vacuum line off and then re-attach it when you are done.

95/GT/5.0 · 08-13-2003, 05:47 PM

Hey guys,Thanks for the info.As I was unsure how to set the fuel pressure.I really appreciate the help.Thanks again from Biloxi,Mississippi

ArtMan · 08-18-2003, 12:35 PM

I beg you, please put 3.73 gears on that car, please.

Coupe50h · 08-18-2003, 02:44 PM

artman, you have a point, being it is a heavier car, i run a 3.27 too, and well it doesnt hurt me too much.

I run 43ps1 of fuel vac off, dunno if thats too much but it seems to pull hard.

95/GT/5.0 · 08-18-2003, 07:02 PM

Thanks for the feedback ArtMan.I went with the 3.27 diff. because I installed a tremec tko 5 speed trans with a .68 overdrive.The original T-5 had a .63 overdrive.After installing the tremec my RMP's when in 5th gear doing 70mph went up about three hundred,I also had to replace the speedo gear to make the speedometer correct.That was with the original 3.08 diff. My brother TRIED to talk me into a 3.55 but I do a lot of interstate driving and ended up going with the 3.27 and now at 70mph in overdrive w/ 245/45/17's my RPM's or about 2400 just about where I wanted to be. I'm an old school Chevy man.EFI is a new one for me not to mention switching from Chevy to Ford after 20 yrs..Too many bolt on mods availible for these Mustangs.Enough to drain your pocket book for an extra 10th or two.I have it set at 40psi right now and I'm going to the track Wed. night to see if there is any improvement in my ET. Thanks 95/GT/5.0

jruppert · 08-20-2003, 10:23 PM

even with my mods, my car still likes around 38 lbs. if i set it to 40 or higher it tends to sputter.

Dark_5.0 · 08-21-2003, 02:24 PM

Quote:

Originally posted by jruppert
even with my mods, my car still likes around 38 lbs. if i set it to 40 or higher it tends to sputter.

Yeah but you got bigger injectors.

08-12-2003, 10:48 PM	#1
95/GT/5.0 Registered Member Join Date: Dec 2002 Location: Biloxi.Mississippi Posts: 49	EFI adj. fuel press.? I have a stock 5.0L with 3.27 ratio diff.,tremec tko,underdrives ;ported cobra intake,65mm trottle body,73mm mass air calibrated for 19lb inj.,cold air intake,155 fuel pump,and paxton adjustable fuel press.regulator.My question is - WHAT SHOULD THE FUEL PRESSURE BE SET AT WITH THIS SET UP?DO I NEED A AIR / FUEL RATIO GAUGE TO SET FUEL PRESS. CORRECTLY?? __________________ 1995/GT/5.0

08-12-2003, 11:53 PM	#2
TMASTER Registered Member Join Date: Sep 2002 Location: TEXAS Posts: 161	this Run 40psi with the vaccum line off, that should be right on. the stock regualtor is to high fuel pressure.

08-13-2003, 09:42 AM	#3
Dark_5.0 Registered Member Join Date: Apr 2001 Location: Staging lane Posts: 4,337	IMO you should be running 38-40 psi WOT fuel pressure which is when you set the fuel pressure with the vacuum line off and then re-attach it when you are done. __________________ 92' LX-Big brakes, Lots and lots of suspension, GT40X heads, Ported cobra intake, stock cam, Vortech SC trim. 00' Lightning-Stock 88'CRX-13 second ego killer

08-13-2003, 05:47 PM	#4
95/GT/5.0 Registered Member Join Date: Dec 2002 Location: Biloxi.Mississippi Posts: 49	Hey guys,Thanks for the info.As I was unsure how to set the fuel pressure.I really appreciate the help.Thanks again from Biloxi,Mississippi __________________ 1995/GT/5.0

08-18-2003, 12:35 PM	#5
ArtMan Registered Member Join Date: Dec 1998 Location: Scarsdale, NY Posts: 45	one more thing I beg you, please put 3.73 gears on that car, please.

08-18-2003, 02:44 PM	#6
Coupe50h Registered Member Join Date: Aug 2002 Location: SanAntonio, Tx Posts: 957	artman, you have a point, being it is a heavier car, i run a 3.27 too, and well it doesnt hurt me too much. I run 43ps1 of fuel vac off, dunno if thats too much but it seems to pull hard. __________________ X-Texas highway patrol ssp 1990 coupe - exploder Gt-40 iron heads, Explorer intake, 19 lber's. E-cam. crane 1.7 rollers. 190fp. 75mm maf. 65mm tb, tubular subframe connectors, mac cai, Asp crank pulley, T-5, king cobra clutch, flowtech 1-5/8 unequals, mac X-pipe Frpp driveshaft, lakewood Lca's. race weight 3,160 12.69 @ 107.35, 1.71 60' 26x8.5 drag's 3.90 gear 13.20 @ 106.91 - 235/60/15 firestones 2.3 60' 3.27 gear

08-18-2003, 07:02 PM	#7
95/GT/5.0 Registered Member Join Date: Dec 2002 Location: Biloxi.Mississippi Posts: 49	Thanks for the feedback ArtMan.I went with the 3.27 diff. because I installed a tremec tko 5 speed trans with a .68 overdrive.The original T-5 had a .63 overdrive.After installing the tremec my RMP's when in 5th gear doing 70mph went up about three hundred,I also had to replace the speedo gear to make the speedometer correct.That was with the original 3.08 diff. My brother TRIED to talk me into a 3.55 but I do a lot of interstate driving and ended up going with the 3.27 and now at 70mph in overdrive w/ 245/45/17's my RPM's or about 2400 just about where I wanted to be. I'm an old school Chevy man.EFI is a new one for me not to mention switching from Chevy to Ford after 20 yrs..Too many bolt on mods availible for these Mustangs.Enough to drain your pocket book for an extra 10th or two.I have it set at 40psi right now and I'm going to the track Wed. night to see if there is any improvement in my ET. Thanks 95/GT/5.0 __________________ 1995/GT/5.0

08-20-2003, 10:23 PM	#8
jruppert Registered Member Join Date: Jul 2001 Location: Reed City Mi Posts: 106	even with my mods, my car still likes around 38 lbs. if i set it to 40 or higher it tends to sputter. __________________ '94 GT, 347 stroker, AFR 185's, Trick Flow stage 2 Cam, Edelbrock upper and lower, 70mm Tbody, 77mm MAF, 24lb injectors, 255 lph pump, underdrive pulleys, 1 5/8 Motorsport Headers, king cobra clutch, tremec tko, 3.73 gears, flowmasters

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