Quick question about reading fuel pressure on TPI
Thread Starter
Le Mans Master
Joined: Jan 2002
Posts: 5,320
Likes: 4
From: Kyle TX (Because Mojo Made me fill it in)
Quick question about reading fuel pressure on TPI
When you turn your ignition to the "on" position and the fuel pump is primed, does your fuel pressure stay constant even if you do not turn over the engine or does it drop? Hope I worded that correctly.
Thanks!
Thanks!
Pro
Joined: Jul 2002
Posts: 729
Likes: 4
From: Yukon OK
Re: Quick question about reading fuel pressure on TPI (VetteNoob)
Just had a good post on this subject and some good info on how to check for leaks.
http://forums.corvetteforum.com/zerothread?id=625410
:cheers:
http://forums.corvetteforum.com/zerothread?id=625410
:cheers:
Thread Starter
Le Mans Master
Joined: Jan 2002
Posts: 5,320
Likes: 4
From: Kyle TX (Because Mojo Made me fill it in)
Re: Quick question about reading fuel pressure on TPI (LaVidaLoca)
Yeah I read that, but my gauge is electric so I just need to find out if the pressure stays constant after the fp primes if the ignition is left on without cranking the engine.
Le Mans Master
Joined: Apr 2000
Posts: 6,341
Likes: 1
From: Shelton CT
Re: Quick question about reading fuel pressure on TPI (VetteNoob)
It's supposed to drop a few psi after you prime it. Mine goes to 41-42psi at prime, and then settles at 37-38psi for an hour before starting to drop very slowly..
Team Owner
Joined: May 2002
Posts: 24,337
Likes: 25
From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
Re: Quick question about reading fuel pressure on TPI (VetteNoob)
The pressure should stay constant during and after priming. The fuel pressure at the rail is the pump output pressure minus the spring pressure provided by the FPR diaphragm. Assuming no injecctor leaks, and no fuel pump check valve leaks, the pressure shouldn't budge.
When you start the car, the plenum vacuum decreases the spring pressure, which in turn decreases the fuel pressure.
When you start the car, the plenum vacuum decreases the spring pressure, which in turn decreases the fuel pressure.
