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PrimeMvr PrimeMvr is offline
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Join Date: Dec 2010
Location: Iowa
Posts: 370
A couple of WUR questions

I've been reading endlessly on proper CIS setup, both here and the Bosch book. I get how all of the pieces work together, except for how the WUR reduces warm CP on light throttle vs. boost.

Since there is only one TB hose, I don't understand how it can control both vacuum and boost enrichment. My understanding is the hose on top of the WUR going to the airbox is nothing but a vent??

My car is running quite well, but I'm sure I'm leaving both power and fuel economy on the table.

Idle AFR is mid 14s. The lightest touch of the throttle in neutral will lower it fairly linear with increasing RPM to high 12s. Light throttle cruise at just about any speed is low 12s and I average around 10 mpg.

WOT drops almost immediately into the 10s and 9s when boost comes on, slowly rising over 5500 RPM and maxing out in low 11s at redline. Can you say "washing the cylinders?"

I can block the boost signal to the WUR with an RPM solenoid, but since it enriches long before boost and even on light throttle, I'm guessing my warm CP is too low to begin with, allowing the sensor plate to overshoot. Which leads me to the question that I cannot seem to find the answer to: How do you adjust warm CP with a stock WUR?

I have a gauge, but want to know how to adjust the pressures before I hook it up. Yes, I know the BL WUR is a great product and pretty cheap, but I enjoy DIY and I'm not finding the answers I need. Maybe I just need to open it up and stare at it for awhile. That worked wonders on my AAR and dizzy. BTW, lambda is open loop.

Thanks gents...learning more every day thanks to Pelicans and trial/error.
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Old 07-01-2011, 10:55 AM
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