Bronze

iTrader: (3)

Hi Guys,
This is my first post so try not to beat me to bad . I've got a 93 with the basic Greddy install. I have also installed a Bipes controller, VTA BOV, Faze A/F gauge, and Faze Boost Gauge. My timing is set at 13 deg and I am running 'WhiteRoadsters' Basic Bipes settings. My problem is I can't get the RPM's at idle down past 1200. It used to run 1000 rpms before I was working on the Cruise control. The cruise control had a major problem due to the fact it stuck wide open and started racing me down the interstate 95+ . I resolved that issue by replacing the cruise cable. It had got too close to the turbo and melted the cover off. The new cable received heat tape so I won't have that issue again. I have checked for a vacuum leak by spraying everything with Carb cleaner and can't find one. I also do have all new silicone vacuum lines on it. I did check the A/F screw on the throttle and it is a quarter turn loose from completely tight. Second, The a/f gauge shows that I'm running a little rich at idle but as soon as I touch the gas driving it will either jump between just rich or bottom end lean, or just drop off the gauge lean and not show any condition. Any Ideas?

bripab007

Vent-to-atmosphere bypass valve.

Joe Perez

iTrader: (8)

+1

Running VTA on an AFM-equipped vehicle is always suspect unless certain precautions are taken. Many valves are slightly open at idle, and thus leak. As a result, you've got unmetered air going into the engine, though this would generally cause the engine to run lean. (Before I removed my AFM, running my FM BOV with no checkvalve would actually stall the engine at idle.)

What kind of BOV do you have?

Also, I hate to be a downer but that A/F gauge you've got is not going to be very useful for tuning a turbo'ed engine. Gauges that use the stock narrowband sensor are only accurate within a narrow range centered around stoich- they can't tell the difference between 10:1 (bad) and 12.5:1 (good). To the narrowband gauge, they're both just "rich."

VRTSid

+1 I added a "check valve" to my VTA dsm "bov" and it stopped the idle weirdness and runs better...

Bronze

iTrader: (3)

I don't know who makes the bov. It came on the car and knowing the PO it probably isn't the best of quality. I'm going to the junkyard and pickup a recirculating valve off of a saab I found. I wish I had the cash and I would pickup its intercooler at the same time. Thanks. Oh one more question when I plumb the valve do I attach it back just beyond the AFM? Thanks

bripab007

You want to attach it so the face of the valve and the spring on its backside are pointed directly at/perpindicular to the charge pipe, while the other side, the vent, would attaches somewhere post-AFM but pre-compressor inlet.

greddymx5

iTrader: (1)

http://www.**********/stats/bosch%20bov%20install.pdf