jasonz28camaro

iTrader: (13)

does the fuel pressure regulator work off vacuum?

I had someone work on my car and i dont think it is put together right. i noticed a picture of someone elses engine and they had a vacuum line coming off the intake manifold to the regulator. mine has the same type of vacuum line that is coming from the main harness that has no vacuum. do i need vacuum for the regulator or not?

Just got the car dynoed and the A/F was lean after 4K, went from 12.something to 13.7. Could this be the prob?

thanks guys anything will help.

Gojira94

iTrader: (4)

There's 2 small vacuum fittings on the pass. side of the intake, just aft of the EVAP purge solenoid. top one goes to a small check valve for the HVAC, bottom one should go to the FPR. top/bottom arrangement of these 2 is not important, but yes, you need vacuum to make the FPR's diaphragm work correctly. Sounds like you got the HVAC check valve hooked up but not the FPR. Is it capped or just open with a vacuum leak?

jasonz28camaro

iTrader: (13)

What is the HVAC? I got the top Fitting going to the regulator and the bottom one capped. Not sure about the HVAC??? I'll take a picture when I get home and post it.

RamAir95TA

iTrader: (2)

HVAC = heater and A/C. The line that comes out of the engine harness operates the flapper doors in the heating vents and feeds the vacuum reserve canister on the passenger side front below and in front of the coolant reservoir.

jasonz28camaro

iTrader: (13)

Does it Make the vents blow inside my car because the heater only blows on my feet and won't blow out the vents.
But that line was hooked up to the regulator.

RamAir95TA

iTrader: (2)

Exactly.

You need a line going from the fuel pressure regulator to the intake manifold and a line going from the intake manifold to that HVAC connection in the engine harness.

qc97z

iTrader: (9)

You're saying the vacuum line from the main engine harness was hooked up to the regulator? That's way wrong, unless there's a "T" there and another line hooked to those is attached at the intake manifold.
At the back passenger's side of the engine bay, there is a vacuum line that goes into the cab. That line is what controls the doors for the HVAC system. If I remember correctly, at that junction, the vac line from the vacuum reservoir (line with the electrical harnesses on the passenger's side fenderwell) and the line from your harness all connect together, and connect to the intake manifold.
Your fuel pressure regulator must be connected to vacuum to work properly. Pros say that your fuel pressure regulator should have its own vacuum line connected straight to the intake manifold. No T's or Y's, no other devices connected. This way, the regulator can react faster to changes in vacuum.

jasonz28camaro

iTrader: (13)

so here's the picture... you can see the HVAC line unplugged, it was plugged into the regulator.

i unplugged it and ran a hose form the manifold to the regulator for the vacuum supply.

now if i can remember correctly the HVAC line was connected to the manifold with at rubber tube extension or something like that?

if i supply vacuum to the HVAC will it make my vents work inside my car?

jasonz28camaro

iTrader: (13)

thank you guys so much. i just went and did it and i have heat blowing out my vents. now we get to take my car and my girlfriend wont bitch because its too cold....

i havent drove the car yet, should i feel a difference when driving with vacuum going to the regulator now?

qc97z

iTrader: (9)

It will work properly...
As you open the throttle body, vacuum will decrease, causing an increase in fuel pressure.
If you had it tuned un-hooked, get it re-tuned.