[911sTarga]

Hello all.

I've read many posts on this subject, but I have yet to find a detailed thread that explains exactly how a CIS system meters fuel and what inputs is uses to do so. I believe it soley uses vacuum, but I'm unsure.

I'd also like to talk about camshafts while using the CIS system, as it appears most people think that there isn't much of a choice here. I think I can give a lot of suggestions and even test quite a few profiles on my engine, but I'm limited on actual CIS "function" knowledge right now.

I have a feeling that the CIS unit uses vacuum for the majority of it's input. I believe this because I have read that you can't use "s" cams with the CIS system. I bet the "s" cam has a tight LC (lobe center) with more duration then a non-"s" cam. What this does is drop the vacuum signal at idle and off idle running....which "might" hurt CIS performance. Again, I don't have full CIS knowledge yet.

Anyway, I'll go into this more in a bit. Can someone chime in on the operation of the CIS and anything they know about camshaft profiles while using the CIS system?

Thanks!

Jay