Cheap A/F monitor rig

[rcamacho]

Folks, I've searched the forum and failed.

I'm looking for some howto on a cheap A/F monitor in order to do some carb fine tuning. I can jet by my seat for primaries on my holley but do not want to take any chances on full power jet coverage.

Specifically, I'm looking for some advice on what O2 sensor to use and whether I can get away with a multimeter or need to pony up for an expensive guage.

 

[MTMike]

I'm curious on this as well. My Holly Projection system is very finicky to fine-tune.

Mike

 

[Emmettology 101]

Back when I was into Probes I had a link to a Do it yourself A/F ratio gauge. It was a good link with alot of details and photos on how to make your own. I searched on the Probe site I used to be on but couldn't find it. ANd the best thing I have foudn so far on Google is this:

http://www.redline.lt/articles/specialfeat/afmeter.htm

 

[dyeager535]

This link work? I think I'd tweak that with a heated sensor though, Delco AFS-74 is good, stay away from Bosch.

Voltmeter will work.

As you can see from the graph, anything over or under 14.7:1 sends the voltage to the extreme in either direction. Under heavy load the engine wants to see richer than 14.7:1, but that's essentially impossible to watch with the narrowband O2 sensors. You at least however, know that you aren't going lean.

Doesn't the projection setup let you watch O2 voltage via the ECM it uses??