View Single Post
JFairman JFairman is offline
Registered User
Join Date: Jul 2006
Location: S. Florida
Posts: 7,274
I'm only suggesting you try what I said and see if it helps. I don't know if it will or not but there's a chance it might.

Adjusting the idle AFR by the CO screw has no direct effect on idle or cruise control pressure it is just reindexing the location or height of the control plunger in relation to the metering slits in the fuel head in relation to the position or height of the air flow meter sensor plate.
So adjusting the CO screw will have absolutely no effect on how hard control pressure pushes the sensor plate upwards against the force of air pushing down on it.

Adjusting the 4mm allen head on the bottom of the B.L. WUR for higher control pressure will affect control pressure at idle by pushing the control plunger downwards and the sensor plate upwards, higher than it was at idle and steady cruise so while it is for adjusting steady cruise warm AFR's it also affects the idle AFR.
Your car is running rich at idle so I would try a 1/4 turn clockwise on the 4mm allen head in the middle of the stainless steel disc on the bottom of the WUR. That will raise CP a little bit and push the airflow metering plate up with more pressure, raising it a hair higher.
You said if you let off the gas slowly your idle is steady and that makes me think the metering plate is settleing to higher position at idle when you do that. Raising control pressure will also make it raise to a higher position at idle so thats why I suggest adjusting it.

I have adjusted my WUR to have these AFR's with the IA modified fuel head when warmed up:
Around 14.5:1 at a steady 30-40mph cruise for decent gas mileage.
Around 13.9-14.1 at idle. Idle is smoothest around 13.5:1-14:1 in my car.

I can adjust it leaner easily with the CO screw but then idle lowers and becomes less smooth. Idle at 14.7:1 is not as smooth as 13.7:1 with 964 cams.

Boost AFR's depend on what rpm and what gear your in. They are far from perfect but CIS never will be and I'm not into spending/wasting any more money on frequency valves and controllers to try and make it better or flatter.

The modified flowtech IA fuel head and B.L. adjustable WUR were almost $1000 together and that plus the AFR gauge and rpm switch/vacuum solenoid and time spent adjusting things over and over are enough time and money spent on the AFR subject for me.

I don't know if that answers your questions but you can try raising warm steady cruise and idle control pressure a little at a time like 1/4 turn clockwise to start and if it doesn't work you can very easily return the adjustment to where it was in a few minutes if you have a small air cleaner on the car during the adjustable WUR tuning process so you don't have to remove the intercooler and factory air cleaner to get at the WUR every time.

When I was adjusting my WUR daily I didn't replace the 2 - 10mm nuts that hold it down everytime, I just slid it off the 2 studs without even removing the 2 fuel lines and tipped it sideways to fit a 4mm allen wrench in there to adjust warm steady cruise control pressure or AFR.

You have to remove it to tap in the stainless steel disc on the bottom with a brass drift and small hammer for lowering boost control pressure to get richer acceleration AFR's.
Old 10-21-2009, 10:05 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #18 (permalink)