NZ951

Are you sure its psi not inches of mercury?

emwporsche

yes, stock cam.

-5 to -8 psi positive.

NZ951

So...

5 psi / 0.4912 = 10.18 Inches of mercury
8 psi / 0.4912 = 16.20 Inches of mercury

I get around 18 inches of mercury... you are not a million miles away at 8psi.

special tool

If you have -5 to -8 PSI - that is decent vacuum. As much as 16 in. HG.
The idle is lousy?

emwporsche

the idle is poor but the hesitation is horrible.
it boggs down really bad.

we couldn't find any vacuum leaks using the propane trick, we couldn't get the idle to pick up at all.

it's really lean, I need some way to richen it. adjusting the A/f screw helped a little bit.

it's also internally backfiring.

jimbo1111

Maybe you can start to richen the mixture with the afpr you have. turn it clock wise until you get a good idle. If you don't have a gauge than use the stock 2.5 bar fpr. Also sounds like the isv or the hoses under the manifold have a leak. If your saying you have good vac at start up than after the isv closes the vac drops that's what you should be checking. You must know what fuel pressure your running. It's critical that the pressure is correct or you will have all sorts of problems lean or rich.

Alpine951

If you are going to unload the injectors i would be interested.

emwporsche

^ no this is only temporary.

I found out that the fuel pressure was at 2.3 bar.

but the 6 month old spark plug wires were arcing on the intercooler pipe

this should help make it run a lot better!