MFI-Check out my sparkplug!
 

http://www.pelicanparts.com/ultimate...oads/Plug1.JPG

As you can see the tip of my spark plug is what I think is a good brown (although a bit dark) for a MFI system. However the rest of the plug is black and sooty indicating a too rich mixture. When I lean the mixture out I get a white tip, but still the rest of the plug is black soot. Is this normal for an MFI system? If not, what should I do? NOTICE!!!! I have and follow all the MFI tech articles including "Check, Measure and Adjust" Thanks

Kurt V
72 911E

Kurt,

What specific plug is that ... BP7-ES, B8-ES?

All I see is black soot ... the metal parts don't get read, just the insulator, and that one is TOO RICH, TOO RICH, TOO RICH!!!

Lean it out!
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Warren Hall
1973 911S Targa
1992 Dodge Dakota 5.2 4X4 parts hauler

[This message has been edited by Early_S_Man (edited 08-07-2001).]

That plug is way to rich. Start one click at a time on the high end adjustment.

Warren, the plug is a BP7ES. If I lean the mixture out more the electrode becomes white and the insulator is still black. I'm afraid that I might cause some harm to the engine with the plug in that condition (white tip, black insulator) Should the electrode and the insulator both end up being the same brown color? Thanks!

Kurt V
72 911E

With unleaded all plug insulators should be white.

Joe Garcia

Kurt,

You can't really read the full-load richness of a set of used plugs ... the idle and part-load running conditions mask the condition of the plug's highway/upper rpm characteristics.

To actually test mid-range and higher mixture richness, you would have to install a brand new set of plugs in a warmed-up engine, then do your highway or track testing, and switch off the engine for a coast-down without power! Immediately pull the plugs and 'read' them ... somewhat of a tedious process, admittedly!
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Warren Hall
1973 911S Targa
1992 Dodge Dakota 5.2 4X4 parts hauler

[This message has been edited by Early_S_Man (edited 08-08-2001).]