what is this????
Thread Starter
Registered User
Joined: May 2009
Posts: 175
what is this????
I went to a meet here in tampa, i raced a stock 350 z well he said he is stock i dont think he is. with d/r he said he ran a 13.5 at the track. he beat me buy a car to a car and a half. i have full bolt ons no d/r but once i hooked he never pulled anymore, but i did not pull him in. wtf my car should be allot faster than this. i knw my fpr is no good could that stop me from getting all my power. i am untuned but i think i should still be able to be a stock z untuned what do you guys think is going on.
Thread Starter
Registered User
Joined: May 2009
Posts: 175
not hard if your working, i was working when i got this motor but it is not the same now. that 350 z is a factory freak lol there are vids on streetfighter where he beat a stock 6.0 gto i will post it up.
this is thelink to the site it is on.
http://mafia-motorsports.com/forums/..._hustling.html
this is thelink to the site it is on.
http://mafia-motorsports.com/forums/..._hustling.html
Registered User
Joined: Jul 2007
Posts: 459
From: Daytona Beach, FL
A stock 350Z is a fast car. What makes you think your camaro should be faster than it is? I dunno what cam you installed but without a tune for all the stuff you have listed in your sig your car is probably slower than it was stock. Not trying to be an ******* or anything. My car would barely run when I got done putting it together until it at least had a mail order tune. Even that was pretty far off.
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Joined: May 2009
Posts: 175
tell me if my test on the fpr are good, this is what i did to test it. we took off the line car not running, it did smell like gas bu no gas on the line. the he started the car and i pulled the line off and no change in idel, so is this the sign of it being bad?? and if it is bad what dose it hurt? will i lose power from this???? or get bad gas mileage?
Registered User
Joined: Jul 2007
Posts: 459
From: Daytona Beach, FL
A bad fuel pressure regulator could do two things. One fuel pressure way to high and too much fuel is pushed through the injectors and your car runs pig rich and poorly. Or, it could put your fuel pressure way too low and when you launch your car down the track the next time it goes way lean and melts all your valves, detonates and busts up your pistons and blow up your motor. Then again like injuneer stated above, with a 93 car and all the stuff you have done to increase airflow since you haven't gotten it tuned it is probably running pretty lean already. Good luck.
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Joined: Nov 1998
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From: Hell was full so they sent me to NJ
I gave him all that in a PM, but I'm not sure if he read it.
Quote:
Originally Posted by sick9lt1
what dose the fpr do and how do i tell if it is bad? and if it is bad how will it hurt the car. thanks man.
- - - - - - - - - - - -
It controls the fuel pressure in the rails, keeping it a specific number of psi above the intake manifold pressure (vacuum). That pressure difference is what determines how much fuel the injector delivers for a given pulse width. If the pressure is too high, the injector sprays more fuel than the PCM (computer) expects. If the pressure is too low, it sprays less fuel.
As a result the engine can run very rich rich or very lean, which reduces power. Run way rich, and the excess fuel can wash the lubrication off the cylinder walls and destroy the piston rings, and dilute the oil, damaging the bearings. Run excessively lean, and the engine will detonate, possibly damaging pistons, ring lands and the heads... and maybe take a few main bearings or rod bearings out.
You can check the FPR by measuring the fuel pressure. At idle, with the vacuum compensation line removed, it should be 43.5psi. GM accepts anything from 41-47psi as within spec. Reconnect the vacuum compensation line, and the pressure should drop proportional to intake manifold vacuum. A drop of about 6-8psi from the "no vacuum line" measurement is normal with a stock cam. The drop when you reconnect the vacuum line will be less than that with an aggressive cam.
Tape the fuel pressure gauge to the outside of the windshield, and take it out on the road. At WOT/max engine RPM the fuel pressure should not drop below 40psi.
If you fail any of those pressure checks, it MAY be the FPR (or it may be the fuel pump, filter, etc.). Next step would be to check the vacuum compensation line for wet fuel, which would indicate a failed FPR.
If you have an Aeromotive LT1 AFPR, it isn't unusual for them to fail.
Originally Posted by sick9lt1
what dose the fpr do and how do i tell if it is bad? and if it is bad how will it hurt the car. thanks man.
- - - - - - - - - - - -
It controls the fuel pressure in the rails, keeping it a specific number of psi above the intake manifold pressure (vacuum). That pressure difference is what determines how much fuel the injector delivers for a given pulse width. If the pressure is too high, the injector sprays more fuel than the PCM (computer) expects. If the pressure is too low, it sprays less fuel.
As a result the engine can run very rich rich or very lean, which reduces power. Run way rich, and the excess fuel can wash the lubrication off the cylinder walls and destroy the piston rings, and dilute the oil, damaging the bearings. Run excessively lean, and the engine will detonate, possibly damaging pistons, ring lands and the heads... and maybe take a few main bearings or rod bearings out.
You can check the FPR by measuring the fuel pressure. At idle, with the vacuum compensation line removed, it should be 43.5psi. GM accepts anything from 41-47psi as within spec. Reconnect the vacuum compensation line, and the pressure should drop proportional to intake manifold vacuum. A drop of about 6-8psi from the "no vacuum line" measurement is normal with a stock cam. The drop when you reconnect the vacuum line will be less than that with an aggressive cam.
Tape the fuel pressure gauge to the outside of the windshield, and take it out on the road. At WOT/max engine RPM the fuel pressure should not drop below 40psi.
If you fail any of those pressure checks, it MAY be the FPR (or it may be the fuel pump, filter, etc.). Next step would be to check the vacuum compensation line for wet fuel, which would indicate a failed FPR.
If you have an Aeromotive LT1 AFPR, it isn't unusual for them to fail.
Quote:
Originally Posted by sick9lt1
so when i have the car running if i take offthe vac line the motor shoould rev up right.
- - - - - - - - - - - - - - - -
No. First cap the end of the vacuum line so you don't have a vacuum leak. The fuel pressure "difference" will raise from lets say 43 to 50psi Your gauge will only read 43psi, because its reading the rail pressure, but the driving force for the injectors is rail pressure minus manifold pressure, which means you add manifold vacuum to rail pressure = 50psi). That means the injector will now be flowing 7.2% extra fuel with each pulse. That just means the engine will run rich for a fraction of a second, until the O2 sensors pick up the slightly rich condition, and the PCM reduces the injector pulse width.
As long as you cap the end of the vacuum line, the engine idle speed will not change. Even if it did change slightly, the PCM would adjust the IAC valve to return the idle to spec.
Originally Posted by sick9lt1
so when i have the car running if i take offthe vac line the motor shoould rev up right.
- - - - - - - - - - - - - - - -
No. First cap the end of the vacuum line so you don't have a vacuum leak. The fuel pressure "difference" will raise from lets say 43 to 50psi Your gauge will only read 43psi, because its reading the rail pressure, but the driving force for the injectors is rail pressure minus manifold pressure, which means you add manifold vacuum to rail pressure = 50psi). That means the injector will now be flowing 7.2% extra fuel with each pulse. That just means the engine will run rich for a fraction of a second, until the O2 sensors pick up the slightly rich condition, and the PCM reduces the injector pulse width.
As long as you cap the end of the vacuum line, the engine idle speed will not change. Even if it did change slightly, the PCM would adjust the IAC valve to return the idle to spec.