larryb

It has to be water. Remove the tank drains, draining into a bucket and see what comes out.

What % power and TIT do you operate at?

Start with the cheapest and most common, spark plugs. I have seen numerous posts here and beechtalk where an owner spent lots of money chasing similar gremlins only to have it be the spark plugs. If you don’t already have a set I would suggest tempest fine wire plugs. If that doesn’t do it mags and the spark plug wire harness are next.

Sven: Do you own the airplane yet? I flew my J for 5 years in the California mountains. It does OK but a turbo is better. If you already own it, it will be OK. But if you don’t own it yet, buy a turbo. Much better. I own a turbo Mooney myself now.

Go on an international vacation, or somewhere too far away to take the Mooney.

Does the HSI and autopilot work correctly for an LPV approach?

The receiver is the nav radio and displays on the hsi. The antenna is common for both radios. There is a splitter feeding the signal to both radios. Since your #2 works we know the antenna is ok. The problem could be your #1 radio or the antenna cable between the splitter and the radio.

These sensors run both + and - all the way to the jpi. So a bad ground is not a consideration. What is a consideration is the connection of the sensor to the jpi harness. There is a star washer that is supposed to go between the terminals. This is specified in the jpi install manual which I would suggest reading. If the connection checks out then swapping the sensor, as already suggested, is a good way to isolate the issue.

I am not familiar with the sync lines are connected, or not, on the various models. Just throwing out ideas on how you can pinpoint the source of interference. Another thought is to run the strobes on a separate power source to see if interference is through the power lead.

You could disconnect the sync line at both ends and see if that has an effect. Then disconnect the strobes one at a time and see if you can isolate the issue more.

I have a lot of those items in a box because I haven’t gotten around to trying to sell it. Most probably won’t get much. I think now days most people just buy an edm when faced with a gauge problem. Check eBay completed auctions for the best guide.

My plane is in the shop right now for this. Last year at annual they replaced the airspeed safety switch. Ever since it has been off on its calibration. Sometimes it works fine. But most of the time I have to press the override button because the switch does not activate at the calibrated airspeed. The shop tried to adjust it once but it is just flaky. This time it is a warranty issue.

Not only does the cable clamp appear to be missing, the valve is not bolted to it's mount. The bolts are present in Maurader's pic but not in Skates pic.

A few points. First, some theory. An engine monitor reads each probe several times per second. Then it will apply some sort of filtering and/or averaging algorithm to the values, and that filtered value is what we see. The more filtering applied, the smoother the response but also the slower the response. We do not know how many times per second the probes are read, and we do not know what sort of algorithm is applied. Probably inside JPI only the person who wrote the firmware really knows this detail. It could be in their design spec, but who knows. Now lets address a few of the thoughts mentioned in the thread. A ground issue is not likely. Each of these probes runs both thermocouple wires all the way back to the JPI. The measurements do not depend on the engine being grounded. The terminal connections between the JPI and the thermocouple are suspect however. I plan to review mine. AC coupling from the alternator is not too likely either. The alternator is several hundred cycles per second, and we are seeing 1 temperature cycle between 1 and 5 minutes. If the JPI reads the probe at the instant an interference event occurs, and if the filtering is not robust enough, we can see an effect in the result. If this is happening, figuring this out will be difficult. I find it very interesting that 3 of us have reported a similar observation. And nobody yet has posted that they have a TSIO-360 and have not seen the effect. I plan to review the tightness of the connections on my #3 probe, and if tight I will swap it out for a spare. Larry

That valve looks closed to me. I would remove the wire and try to move the lever and hopefully free the brakes. With the wire separated from the lever you can figure out if one or the other does not move freely.