Guys,

These things used to be very good at evaluating the carb perf on motor homes with big block V8s. Those can be loaded and the gas pedle posit changed and you can see the mix change. The rps are held constant by the massive load so you get some time. I installed a new carb once and found it was exceedingly lean at 3/4 throttle without the secondaries. That was a popular threottle posit and would most assuredly have cost me the engine. That little gauge paid for itself. That is IMO and that was then and that was a carb. engine.

So much for the anecdote. Are these things workable on our modern FI engines? How would you suggest I use it to get a clear pic of the various mix ratios at diff rpm's and loads? Comments on brands and sources?

Thanks for your comments.

John

 

autometer makes them in all shapes colors and sizes all you have to do is connect 3 wires .one to the o2 sensor and the others to an ignition source .people usually use it on forced induction applications

 

those are a lights show, as they don't really tell you much. What he needs is a WIDEBAND O2, so he can accurately monitor his air fuel ratio, datalog, and tune. It's the only way.

There are a few companies that make one, but be prepared to spend 300-500 bucks on them.

 

i used an AEM wideband on my last car. i loved it. i would not recommend getting a narrowband one.

 

Narrowbands are useless. Get an AEM Uego or FJO

 

Yep, I have a AEM, works great!