What will the fuel pressure gauge read at idle? AFPR is set at 41 PSI. Just curious, my gauge reads 36 PSI.

 

i'm not 100% sure but to get an accurate reading you have to undo the vaccume line that goes to the plenum.
Andrew

 

Smokin is right you will have to remove the vaccum line and plug it with your finger or whatever to get a completely accurate reading. Also if you can plant that Gauge somewhere you can read it and drive around to see if you get the same reading at WOT.

 

Let me restate my question? The fuel pressure is set according to precedure at 41
psi. Now I have a fixed fuel pressure gauge mounted to the fuel rail. My gauge reads 36psi while the car is idling (not WOT) is this a normal drop in pressure? Thanks

 

Yes. The pressure will drop 3-7psi. when engine vacuum is applied to the backside of the pressure regulator diaphragm at idle. At WOT, the pressure should go back up. Your car is fine. Hope this helps.

------------------
1990 IROC 350
Mods: Too busy trying to make it run right to mod it.
Airfoil, Dynomax cat-back, MSD coil, 180 t-stat, Bald Eagle tires,
Hypertech fan switch, Accel 23# injectors, Holley AFPR, ported plenum,
Ported Daytona Yellow stock base, Moroso valve covers, other stuff,
Ruger P95DC, hot wife, new oil filter, thick rubber floormats, no cats.
18.0 @ 85MPH since I'm one big-a$$ MF
"It's better to have and not need than to need and not have."

 

Z28,

Your fuel pressure is almost perfect. The stock specification for fuel rail pressure at idel (vacuum line connected to the FPR) is 37 PSIG, ± 3 PSIG. You're within one PSI of the presumed "ideal" factory setting, and that's not considering the acceptable error percentage of your gauge.

------------------
Later,
Vader
------------------
"Let the bodies hit the floor!"
Adobe Acrobat Reader

 

Thanks, the last two replies puts my mind at ease. After running too rich with the stock
regulator and setting the new adjustable one
to 41 PSI and with the idle at 36 PSI the engine runs strong and shifts at 5200 rpm's
now.

------------------
1987 Black Camaro IROC-Z (original owner) Replaced LB9 @ 86100 miles.
New 350 Crate engine
Balanced & blueprinted
WP 67cc Heads 9.6:1 C.R.
Cam: 450lift,216dur@50,110ls
TPI Induction(from 305)
22# Fuel Injectors,AFPR&Gage
SLP Intake runners
New Computer chip
K&N filters & Air Foil ,
Hothkis STB
SLP 1 3/4 Headers
CATCO 3" Catalytic conv.
SLP 3" Cat Back Exhaust
700R4 Auto
SLP Torque Converter (2400 stall)
B-W 9 bolt rear 2:77 Possi. Four wheel disc brakes,245/45/ZR-17 Tires
17x8.5 ATI 5 Razze Wheels
EST. 340HP
380#/ft of Torque
NEW TOY!

 

Don't leave the gage attached to the fuel rail permanently or you may experience a car fire.

 

What is the optimal PSI setting for a TPI? I thought it was higher, something like 48psi. Or does it vary that much between applications?



------------------
1987 Camaro IROC-Z
350 TPI (L98), HyperTech Airfoil, K&N Filters and modified airboxes, AC Delco RapidFires, Taylor SpiroPro 8mm wires, Energy Suspension polyurethane bushings for front and rear LCAs and sway bars, KYB struts and shocks, BFG g-Force Z-rated tires, MAC STB, MAC SFCs, JET low temp stat, CarSound Hi-flow Cat, DynoMax 3" Mandrel-bent pipes, Flowmaster muffler, 3" chrome tailpipes, Corvette Servo, TransGo Shift Kit, Corvette 2000 Stall, TruCool LPD tranny cooler, T-tops, and White exterior with red leather interior.

2001 Sunfire GT
Bone stock 2.4L, 5-speed, K&N cone filter, interior detailing, 200W Monsoon Sound System (8 speakers), Silver Metallic exterior with grey interior.
3rd Place Stock Class at annual 2001 JCO Bash

Web: http://www.angelfire.com/on3/whitelightening

 

Fuel Pressure gage is mounted under hood wiht
3ft SS braided hose to a Autometer FP Gage.
My optimal Fuel Pressure is 41 PSI with a Air/Fuel Ratio of 13:1, Vader was correct.
Just had car Dyno'd and these numbers were
verifid for my TPI set-up.

------------------
1987 Black Camaro IROC-Z (original owner) Replaced LB9 @ 86100 miles.
New 350 Crate engine
Balanced & blueprinted
WP 67cc Heads 9.6:1 C.R.
Cam: 450lift,216dur@50,110ls
TPI Induction(from 305)
22# Fuel Injectors,AFPR&Gage
SLP Intake runners
New GM 1988 chip
K&N filters & Air Foil ,
Hothkis STB
SLP 1 3/4 Headers
CATCO 3" Catalytic conv.
SLP 3" Cat Back Exhaust
700R4 Auto
SLP Torque Converter (2400 stall)
B-W 9 bolt rear 2:77 Possi. Four wheel disc brakes,245/45/ZR-17 Tires
17x8.5 ATI 5 Razze Wheels
Dyno results: 211 RWHP & 282 RWTQ.
264 HP & 352#/ft at flywheel. NEW TOY