Ok, so I got my Comptech SC W/AC on about 2 weeks ago, I just put a wideband on my car and to my surprise it was running very lean. When I got the supercharger, I left the adjustment setting on the FMU alone and I'm running the stock 5.5PSI pulley. Considering I live at almost 5000 feet above sea level, and got the kit from Chicago, I figured, if anything it would be rich. I put a B&M gauge on it and ran the static pressure up to 80PSI to see if we could make it go rich. But the lowest we were able to get it was 12.5 right before VTEC, then it jumps to 14.5 and eventually drops to 13.5 at redline.

I borrowed a Vortech 12:1 FMU from a friend and hooked it up according to the installation manual. It instantly went lean and I put the Comptech FMU back on.

It seems I'm running out of options. From the looks of it, I'm getting an AEM and larger injectors as soon as I can afford it. But I didn't think I would have these problems with the bolt on stock kit from Comptech. Any thoughts or input would be much appreciated.

The only mod I have currently, is a Invidia 70MM Testpipe.

 

I had my brand new CTSC with AC on for about 1500 miles before getting it tuned. I have a testpipe and stock exhaust. I had it tuned with a VAFC2, dyno & adjusting the Comptech FMU. My tuner said my car was dangerously lean when I got there, and that the Comptech FMU was turned down all the way!

 

you can try tightening the screw down on the riseing rate regulator should richen a little.....but 13.5 at redline is not that bad.....you should be right at 13.0 on stock boost

You should go AEM and bigger injectors ASAP anyway.....the stock setup is junk

 

Yeah, I've never really liked FMU's, but it came with the kit and figured it would work fine for stock boost. I've turned the screw almost all the way in, and still not getting close to 13.0, I'm getting kind of worried on the high pressure in the fuel system though, but it's the only way I can keep the a/f somewhat safe.

I just don't understand why it's not running pig rich with over 4000ft of elevation change. I have worse A/F ratios than most people at sea level.

 

this may be farfetched - but did you upgrade your fuel pump when you did the kit? you didn't make any mention of what kind of pump you were using, and that might be a big piece of the puzzle.

 

sometimes the pumps go bad also.

 

Yep I replaced the OEM pump with the Walboro 255 LPH.