EGT/CHT problems

Hi guys

I've got a JPI 700 on my RV-4 and yesterday after replacing the alternator I did a run-up to check everything out and to my surprise I didn't have any indications initially on number# 3..

After a few minutes, I started getting a very low reading on the CHT but nothing on EGT and the JPI was telling me about the spread between the remaining cylinders.I shut down and wiggle the probes connections and recheck with the engine off and I had a temp reading on # 3...

I re-started the engine and again no indications...

Anyone ever had this problems and have any idea what could be the cause??

Thank you for your imputs

Bruno
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Interesting that the others did not play up. Usually a grounding problem is the issue and you will see it on all probes.

Being just one it may be you have damaged a wire and do not realise it while working under the cowl.

Basically check from probe to connector. Seems odd you have both EGT and CHT playing up. Unless of course that cylinder is not running very well, but I am pretty sure you would have noticed that

Hi David

Yeah, sure is weird...I've send an e-mail to JPI Support and will send them a download of the data tomorrow and see if they can figure something out...

As far I know, I didn't touch any of the wires in the harness when I installed the new alternator but it is still a possibility.

I will remove the probes tomorrow and clean them out and will recheck all the wiring...

I never had any problems so far with this unit..

More to follow..

Cheers

Bruno

EGT/CHT problems ''UPDATE',

UPDATE

Today I had a look at the wiring of my EDM-700 and found the cause of my problem..

David, you were right ''Being just one it may be you have damaged a wire

I had removed a clamp holding the EGT/CHT wiring and upon re-installation I squizzed the wiring of EGT 3 , cutting the insulation just enough to ground the probe and causing all kind of funny reading..

I disconnected the wire, put a tubing over the little cut and that was it..

Did a run up and everything is fine..

Emergency is over..Yessssssssss


Bruno

Great news, glad I could help.

Ask me how I know about alternator faults........... one small rub point.....cooling duct is metal wound wire.....grounds out....

Strange things do happen