JeffM

My intent at this time is to sell it on Ebay. Thanks

I have a Redline Sidewinder airplane tug for sale on ebay which I used on a Mooney. https://www.ebay.com/itm/273454764917 Thanks

I have not done a gami test in awhile, but I do remember #3 peaks first and the next cylinder peaks almost immediately thereafter. I will recheck the gami spread the next time I fly the plan. I think I will also clean the #3 injector and see if I can switch the electroair plug to the upper hole and see what happens. I think my plug wires are good due to the fact that they are new and the resistance is within the manufactures spec. Thanks for the input and I will post any additional information I come up with. Jeff

# 3 is the hottest cylinder. Good information could probably be obtained by switching the electroair plug to the upper plug hole on number 3 and put the left Slick plug in the lower hole and see what happens. I may see if I can borrow some longer plug wires from my mechanic and do this. With respect to swapping the coils, everything is in one coil pack that is electronically controlled. While I can probably switch the 3 and 4 leads, I do not think I can switch 1 and 2 for 3 and 4. I possibly may be able to get a loaner coil pack from electroair to trouble shoot this. The reason why we have been isolating the problem to the ignition is because #3 runs well on the left mag. I think I need to take a closer look at the injector and give it a good cleaning. Baby food jar test would give a good indication of what the #3 injector is doing in relation to the other injectors. Thanks for all of the good ideas! Jeff

I am unable to easily switch the top and bottom ignition leads. The plug wires for the top plugs are a bit too short.

There is one coil pack for the entire electroair system. My understanding of the how the coil system works is that there are actually only two coils that are contained in a single coil pack unit. One coil is for plugs 1 and 2 and the other coil is for 3 and 4. The way it works is the spark plugs for 1 and 2 always ignite at the same time. When number 1 ignites during the compression stroke, number 2 ignites at the same time during the exhaust stroke. Because number 2 ignites during the exhaust stroke, it essentially is a wasted spark. When 2 ignites during its compression stroke, 1 also ignites but it is now in its exhaust stroke. Process is the same for cylinders 3 and 4. This is how the system runs 4 cylinders with two coils. Logic would indicate that if the coil for number 3 is weak, it would also be weak in 4 because this coil is used by both cylinders. This is why tech did not think it was coil issue because we do not see problem in 4. I suppose I could put the number 4 coil lead on 3 and the number 3 lead on 4 and see what happens. A little nervous doing this.

We did rotate the plugs and the problem did not follow the plug.

Tried three different plugs in the number 3 cylinder, result was always the same.

I have a M20F with an A3B6 engine. The left mag is a conventional Slick mag and the right mag is an electroair electronic ignition system. Flying at 4500 msl with 21 inches of manifold pressure at about 30 degrees lean of peak, if I turn off the electroair system and run only on the left mag, the egt's for all cylinders stabilize fairly even at over 1400 and the engine runs fairly well. If I switch to the electroair mag and turn off the left Slick mag, cylinders 1,2 and 4 stabilize at an egt over 1400 but cylinder 3 drops off and egt goes down to under 400. Engine runs rough. If I enrich the mixture about 1 to 2 turns, number 3 will come alive and the egt will stabilize at over 1400 which is consistent with the other cylinders. Engine then runs smooth. When I start the process, fuel flow is about 6.7 gph. The fuel flow at which the number 3 comes back alive is about 7.5 gph. The plane has gami injectors and the fuel flow is fairly well balanced. I have a JPI 830 engine monitor and am in normalize mode. Checked the resistance in all spark plugs and they all were within specs with readings between 650 and 725. I just installed new spark plug wires for the electroair side of the ignition system and the resistance for all plug wires is within the manufactures specifications. I tried a different spark plug in number 3 and results were the same. Number 3 is my leanest running cylinder. The electroair plugs are in the lower plug hole. Recent compression test on this cylinder was 78 over 80. We looked for an intake leak in number 3 cylinder and were not able to locate any leaks. This problem does not show up during a runup mag check while on the ground. Engine has about 900 hours on it and runs great. My mechanic is not sure why this is happening but does not seem to think it is a problem. I talked to the electroair tech and he thought it may be caused by the fact that the cylinder is running very lean and there is not enough fuel in the cylinder to be ignited consistently by the lower plug. Once mixture becomes a bit richer, lower plug can ignite it. Upper plug is located closer to the injector where fuel mixture may be slightly richer which enables it to be more readily ignited by the upper plug. He also indicated it may be related to the duration of the spark being different for the electroair system and the fact that turbulence in the cylinder may kind of blow out the spark. Not sure I agree with the blowing out the spark theory. My feeling is this cylinder is running so lean that it is just able to fire on the upper plug but not the lower. I also wonder if the the electroair coil for number 3 is weak which results in a weaker spark that is unable to ignite a very lean mixture. New coil pack is $510 and I do not want to jump into buying one. Planing on flying it for awhile and watching it. Any thoughts on this would be appreciated. Thanks, Jeff