Red97LT1

iTrader: (8)

Trying to track down a P0174 code and I see no obvious signs of vacuum leaks,etc. I'm going to smoke it in a few days just to be sure I'm not missing something.

I hooked up the FP Gauge and here's what I am getting....

Ignition on,engine off 38 psi
Ignition on, car idiling 32 psi
ignition on,car idling,popping the throttle 38 psi

Does these look ok or are they too low?
Car is stock with 1k miles on new engine. The code went away for a month and then came back,nothing was done in that time.

Ollie8974

What is the stock specification.

silversweetZ

iTrader: (11)

If you're still on the stock fuel system you should be at 58psi all day.

Red97LT1

iTrader: (8)

yep,stock fuel system.

Lonnies Performance

iTrader: (16)

58psi is for LS1's...
If it's an LT1 it should have 43psi with the vac line disconnected from the regulator.

The idle vacuum will change the idle pressure.
With a stock cam, 32-35 at idle is close.

Red97LT1

iTrader: (8)

It's a LT1. All stock,except for cai.
I'll remove the reg. vac line and see what happens.

Red97LT1

iTrader: (8)

Around 42-43 psi with Regulator vacuum hose removed.