Frank HDC Posted August 17, 2022 Report Posted August 17, 2022 My JPI830 has a consistent issue of "temporarily" showing either my oil temperature off the charts, then back within range...the CHTs of 1 or more cylinders temporarily redlining, then coming back within range..the OAT ALWAYS read high by 5 to 10C. The old steam gauges are always in the green. In fact on the way home from OSH every CHT went red on me! Why is this happening? Bad grounding, inproper probe placement. My avioncis guy said to disconnect the old, original one CHT probe....not sure what that would do. Any thoughs? Quote
Will.iam Posted August 17, 2022 Report Posted August 17, 2022 Well for one you can not disconnect the original ship’s probe as its required for flight as you have a JPI830 a JPI900 or 930 and you could get rid of all the original equipment as it’s certified to be primary. As far as wacky reading go, sounds like a loose connection to those instruments. I would think bad ground would effect all of them at once but why not call JPI directly they are uncanny how they can troubleshoot most problems over the phone. I guess they have been around so long they have seen or heard pretty much everything. Quote
Marauder Posted August 18, 2022 Report Posted August 18, 2022 My JPI830 has a consistent issue of "temporarily" showing either my oil temperature off the charts, then back within range...the CHTs of 1 or more cylinders temporarily redlining, then coming back within range..the OAT ALWAYS read high by 5 to 10C. The old steam gauges are always in the green. In fact on the way home from OSH every CHT went red on me! Why is this happening? Bad grounding, inproper probe placement. My avioncis guy said to disconnect the old, original one CHT probe....not sure what that would do. Any thoughs?Check the P connectors on the back of the unit. It’s unlikely a number of probes would go bad at the same time. Sent from my iPhone using Tapatalk Pro Quote
carusoam Posted August 18, 2022 Report Posted August 18, 2022 To get so many bad readings at one time… A ground wire may have stopped grounding properly… The history of voltage is available by downloading the data from the JPI… If it is steady… probably not a problem… If it is noisy… you have probably found the issue… Pp thoughts only, not a mechanic… Best regards, -a- Quote
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