high cht # 3 io360 a3b6

[mooney2201]

i am getting high cht temps on cyl 3,, 417 degrees the highest,,,this just started and i have done everything but pull the cyllinder,jpi 930 is brand new,all cyl are good.changed spark plugs,changed probes,cleaned injectors,still high,any thoughts,baffel is new also,,just stumped,dont know if the new jpi 930 is bad, just have to switch probes around,,any comments welcome

[garytex]

3 is a hot cylinder anyway, and it is the factory cht location. The old gauge is required to still be operable after installation of a JPI, and theoretically (legally) in the bayonet location in #3. Frequently that means that when an additional engine analyser is installed, #3 gets some odd, not in the usual bayonet location thermocouple. One common thing mechanics do is to put in a spark plug gasket thermocouple. If placed under the bottom #3 plug temps will be in the range you indicate, and in summer, much higher. JPI says "don't do that, it'll scare you" They're right. Check your thermocouple location and type on the offending cyl. Been there done that.

Luck, Gary

[Lood]

I'd just like to confirm: Seeing that the JPI930 is certified to use as a primary indicator, is the original factory probe still required on #3 or not? My thoughts were that if the stock gauges on the panel may be removed when fitting a JPI930, what use is there to still keep the original probe on the cylinder?

[scottfromiowa]

I'd just like to confirm: Seeing that the JPI930 is certified to use as a primary indicator, is the original factory probe still required on #3 or not? My thoughts were that if the stock gauges on the panel may be removed when fitting a JPI930, what use is there to still keep the original probe on the cylinder?

Nothing. Pull it. If you have a certified primary gauge that is a vast improvement over the OEM indicator. Sleep easy,

Scott

(I can't wait to read about the "original equipment list" blah, blah, blad adnosium...)