see attached image.
I have a rich running engine. AFR 9:1 !!! Fuel injected.
Some emissions bits have been removed.

line marked "1" goes from the crankcase to downstream of the AFM (air flow meter), sees crankcase pressure.

line marked "2" goes from the inlet manifold to downstream of the AFM (air flow meter). It is manifold pressure. 20"Hg to 7 psi boost.

line "3" is from turbo compressor outlet to throttle body.

line "4" is AFM to compressor.

Does this sound right? manifold pressure back to the line after the AFM? would this not stuff up the AFM sensing?
What would the effect of crankcase pressure have on the AFM reading also?


[Edited on 20-3-2003 by speedster356]

i would think putting the breather line before the AFM was normal, i think the AFM wouldn't be reading the blow by that would be going to the engine.

there is very little pressure from the crankcase but a lot of "suck" from line "2" at idle as you would expect. would that not tell the AFM to say to the computer .....give me more fuel to try to get the correct AFR?

I is scratching I's head

looks right to me...the AFM measures the air comming into the engine much like a MAP TPS combo on my car.
crankcase breather looks cool
line 4 looks cool
I'm confused by the purpose of 2...its like a vacume line for a booster or a carbon canister...why would you bypass the TB?
I take it 3 is the vacume signal to the wastegate?
just guessing its late and my assignment still ain finished

are 3 and 4 your intakes or are they vacuum hoses?

I dont like #2 at all. its serving no purpose at all that I can see. Try blocking it. See what happens.

[Edited on 21-3-2003 by amazer]

3 and 4 are intake.
I called the turbo help line today...Mr Harris, and he said that 2 was an idle bypass...so when the throttle is slamed shut the engine doesn't die...I didn't understand fully but I will clarify. Better still.....post a reply Leigh.:beer