WKMCD

iTrader: (2)

I swapped out a very dirty BP Vortex CAI for the Halltech Venom on my 403. The BP unit was very dirty even though I cleaned it about 4k ago. The Halltech moves the MAF to the TB end of the airbridge. The filter is huge and the filter area is probably 4 times what the BP unit was. Now the car is running SUPER lean and I mean 17.5-18.0 at cruise and never runs below about 15:1 when I hammer it. BTW: I have a WB guage in the pillar.

I've raised the fuel pressure to 63lbs to richen it up until I can get it tuned. Lean cruise is now about 15.7-16-5, still too lean. Where should my 1500rpm cruise AFR be?

Question: Could the dirty Vortex really have been that restrictive or did moving the MAF have that much effect? I'm running an OL MAF tune so no O2's.

The tune was spot on before.

Thanks,

Kevin

Vas@diablosport

Ideally, you should be running at 14.7:1 AFR. It sounds to me not so much as a tuning issue as much as a vacuum leak. You might try double checking your clamps again or repositioning everything. If that takes care of the problem you will want to readjust your fuel pressure.

WKMCD

iTrader: (2)

I was hoping it was an air leak - unfortunately no. The car idles fine and I've double checked the clamps and hoses.

Schwanke Engines

iTrader: (1)

Moving the MAF could do that. It does get touchier the closer it gets to the TB. Also, like was said, it could still be an air leak. The engine will compensate for idle even though there is a leak. Take some a propane torch, unlit of course, and go around all of the sealing areas. Your idle will change if there is a leak anywhere.

WKMCD

iTrader: (2)

Checked everything for a third time last night. No air leaks.

Frost

iTrader: (45)

It's not a leak, the MAF's calibration changes every time it is moved around in the intake tract.

Why not just put the old CAI back on until you can get the car retuned?