Ferrari Mailing List: Re: Dear Diary - hot start troubleshooting continues

[Jason Polzer (jason]

On 20-Aug-06, at 12:11 AM, Paul Bennett wrote:
<snip questions I have no idea how to answer>

> 2)  What type of tester is used to measure the air/fuel mixture?
> If it is running rich how can I find out?  ( I live in a non-DEQ area)

Look on google for different pictures on how to read spark plugs, for 
example:

http://www.dansmc.com/Spark_Plugs/Spark_Plugs_catalog.html

The best way to test plugs is to drive around, then shut the engine off 
before idling.  Or do a full throttle blast and turn the engine off, 
coasting to a stop.  Pull a spark plug and it should have a nice tan 
colour on the white insulator part.

Ather option is to find a dyno shop that has a wide-band air/fuel meter.

Third option is to read the millivolts on the O2 sensors when running.  
*Please verify Ferrari numbers* but for most sensors they will read 
from 450mv (cruising 14.7:1) to 800mv (rich, like 10:1)  under full 
power.  This option is not that accurate but can help ball park.

Good luck!

Jason