---------------------------------------------------------- Engines-List Digest Archive --- Total Messages Posted Fri 06/20/03: 2 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:47 AM - Re: Engines-List Digest: 4 Msgs - 06/19/03 (Jerry Reynolds) 2. 04:57 PM - Re: Re: Engines-List Digest: 4 Msgs - 06/19/03 (Grant Corriveau) ________________________________ Message 1 _____________________________________ Time: 04:47:28 AM PST US From: "Jerry Reynolds" Subject: Engines-List: Re: Engines-List Digest: 4 Msgs - 06/19/03 --> Engines-List message posted by: "Jerry Reynolds" > Time: 03:22:57 PM PST US > Subject: Engines-List: Getting another Zodiac BACK in the air.... > From: Grant Corriveau > > --> Engines-List message posted by: Grant Corriveau > > ... the problem has to be in one of the Hall Effect sensors (or the lead/wires from > there to the computer)...> > > Grant Corriveau > C-GHTF / HDS / CAM100 Grant, Speaking only generically regarding Hall effect sensors and their applications.. I have seen significant variations in sensitivity (output switching versus distance). However temperature can also cause havoc, without certainty as to the particular failure mode. Calibrated melting paint sticks are available to determine if recommended temperatures are being exceeded, but I would be more inclined to check that, with a new sensor/new lead installed. If the gap is too small and the magnet is making contact with the sensor, you'll probably generate a mechanical failure, and I would not suspect it to be intermittent. But it would need to be resolved regardless. Variations in gap can cause slight variations in switching characteristics, up to and including non-switching as the gap is increased, depending on sensor design. How much play is in the crankshaft? Check for lead damage as well. Jerry Reynolds ________________________________ Message 2 _____________________________________ Time: 04:57:57 PM PST US Subject: Re: Engines-List: Re: Engines-List Digest: 4 Msgs - 06/19/03 From: Grant Corriveau --> Engines-List message posted by: Grant Corriveau > From: "Jerry Reynolds" >... How much play is in the crankshaft? Check for > lead damage as well. > Jerry Reynolds Jerry, I appreciate the information. As soon as I get time I will be changing out both cables/sensors -- they weren't intended to be changed so this involves supporting the front of my engine, detaching the belt drive and sliding it forward enough to enable me to pull out the old units and thread in the new ones, then assemble the plugs, heat shrink, etc.... One step at a time... Probably the most likely culprit is a bad connector in one pin somewhere that is affected by heat ... i.e. the cable grows just enough to make a connection ground out or go high-resistance and that signal is lost. As soon as it cools just a little, it returns to normal, so the problem is intermittent. That is my 'most likely' guess. Once the cable is changed and I'm flying again, I'll just have to 'push the envelope' heatwise again, and see what happens. Hopefully nothing! The good news is that the other channel works fine and has prevented any off-airport landings. Thanks again, -- Grant Corriveau C-GHTF / HDS / CAM100