Or the check valve in the rear fuel feed pipe.
Fuel pressure dropping?
Thread Starter
Burning Brakes
Joined: Jan 2008
Posts: 1,005
Likes: 1
From: springfield MO
Fuel pressure dropping?
Its a 2000 Vette, when I hook up the fuel pressure gauge and turn the car to on it reads 56psi not 58 like I read that it should but if I leave the car to on the pressure slowly starts dropping when it got below 48 I disconnected the checker.
Should it be dropping like this? Its too late for me to start up the car without pissing off all the neighbors so Ill wait til the morning to see what the pressure does while its running but still thinking it should have gone to 56-58psi and stayed there and not slowly dropped right?
Should it be dropping like this? Its too late for me to start up the car without pissing off all the neighbors so Ill wait til the morning to see what the pressure does while its running but still thinking it should have gone to 56-58psi and stayed there and not slowly dropped right?
Team Owner
Joined: May 2001
Posts: 36,836
Likes: 244
From: Dear Karma, I have a list of people you missed.
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16
Thread Starter
Burning Brakes
Joined: Jan 2008
Posts: 1,005
Likes: 1
From: springfield MO
With key in the on position itll show 56psi then within a minute drop below 48 either the valve isnt screwed on enough or its something else but the valve does seem like its screwed on all the way.
Team Owner
Joined: May 2001
Posts: 36,836
Likes: 244
From: Dear Karma, I have a list of people you missed.
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16
RonSSNova's suggestion about a possible leaking fuel injector is another good idea to keep in mind, not to mention the obvious check for any leaks anywhere else in the system, i.e. fittings/quick-connect plugs, injector o-rings, etc. Make sure there are no leaks at the fuel filter as well.
I agree with you that that does seem like too fast for the pressure to be dropping off after turning the key off.
No.
Are you experiencing some sort of problem? Fuel leaks? What prompted you to check the fuel pressure in the first place?
Btw, if "the valve" (I assume you mean the test-port fitting on the fuel rail) is not tight, you would be seeing a fuel leak.
Team Owner
Joined: May 2006
Posts: 21,473
Likes: 356
From: Palmdale, Ca----- 2009 Cyber Gray 4LT A6 F55 452 RWHP 422 RWTQ- RIP 1998 C5 734 RWHP & 585 RWTQ-----
Remember that the Fuel Pump "ONLY" stays on for a short while and then shuts off if it does not have a signal to keep the Relay feeding the voltage to the pump!
I will then bleed down - 56 PSI is nothing to be concerned about!
The main concern should be, does it drop when it is running or under WOT?
If you feel the pump is weak or too old then I'd suggest you drop in an LPE pump, you can get it from Racetronix or you could also run a Racetronix Fuel Pump Hotwire Kit (it comes directly off the Alternator for better running voltage)
Thanks,Matt
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Pro
Joined: Aug 2010
Posts: 622
Likes: 169
From: Montgomery Texas
The fuel pressure should not leak down as rapidly as you indicated in your original post. This could cause difficulty in starting the engine, after a hot soak - the fuel could boil in the fuel lines, if not kept under adequate pressure, causing a vapor lock condition.
It is not clear to me what your symptom/complaint was, or if it has been resolved.