Hm, I think it's the ECU. It's the silver rectangle box for the fuel injection, there's a little knob on the top edge of it. There are two red lines to mark where it's set. What's that thing do? I noticed on a coworker's car, it has red lines on the case and on the knob... but they're not lined up. Like they've changed the setting from where the lines were drawn...

What lines .........? Not factory. It's the mixture adjustment for idle ONLY, and should be set with a CO machine. There are "clicks" that can be felt with the fingertips as adjustment is made. A rough adjustment would be highest idle, once everything else is right. The Cap'n

mine did pretty much nothing...of course the rest of my FI system was falling apart, so that could have had something to do with it:)

You'll find it only makes a difference when the rest of the FI system is working properly, especially the vacuum system.

Eric Read

Hm, yeah, it's red lines that someone has painted on there. Didn't know if it was a factory thing. But there's two alignment lines on the case and two on the knob. But they're not lined up, making it obvious that it's not set the same way it was when the lines were drawn on there.

His FI system works fine but the idle is actually high.

The knob has no purpose. Its purely ornamental and is there to frustrate people, make them feel like they have control over what is actually three strings that all wrap around a wheel to provide the most wild ass guess at a fuel map that they could come up with at the time.

Rich

Its the Boost controller!