Fowards and Backwards

Good news, bad news, good attitude.

The good news is the engine runs! Having said that, this is all extremely uncharted territory, and if it wasn't for Lynn French, I would be completely in the dark. Lynn is the character that first installed an electronic fuel injection and ignition, in his Tri-Q-200.

I used Bosch 24 lh/hr. fuel injectors, sometimes referred to as "blue tops". These are the same size that Lynn uses and it seemed like a good starting point. The ECU is programmable and you can adjust the fuel flow to your own particular application and injectors. When we first got it started, it was extremely rich. I mean rich, to the point where there was black smoke plainly coming out of the exhaust and now there are two major soot streaks running down the belly.

The first few times I ran it, it was kind of a sensory overload; all these new dials, buttons, and the like, to learn. And, it seemed like some features worked and some didn't. It was, and still is, a lot to sort out.

There is a fair amount of programming of the controller to do. The idea is to first match the basic flow of the injectors to the engine, then to map out the mixture tables.

Adjusting the mixture is interesting. First, instead of a mixture knob that you pull out, there is a mixture dial on the Programming Control Module (PCM). You use the dial for tweaking, but you use the Program Variable, Mode and Store controls to make your adjustments permanent. (Over simplification, really).

To adjust the mixture, you really can't use the conventional EGT. We welded a bung into one of the exhaust stacks and have installed a Bosch automotive oxygen sensor. This is connected to a gauge in the cockpit and it provides a digital presentation if the mixture is rich or lean. This gauge reacts much faster than a regular EGT and is easy to interpret. The first sensor I bought didn't work very well, so I bought a better one which has it's own heater.

The O2 sensor is temporary. They are designed for unleaded fuel and after a while 100LL is said to clog them up. I only need it though, for the initial mixture mapping.

All of this is so new to me and there is so much to learn. Sheesh!

After a while we (C-Rod and I), came to the conclusion that the programming button wasn't working. Now, we may be mistaken, but we think we have it right. Anyway, after lots of diagnostic e-mails, back and forth, with the controller designer/manufacturer, I pulled the unit and am returning it for evaluation.

I will say that the engine starts easily, and seems to run fairly well, considering. There are lots of unknowns here, I have an automotive racing throttle body, homemade induction system and lots of seat-of-the-pants engineering, so I am taking everything in stride.

I guess I'll work on my taxes while I wait the outcome of the controller.

My Red Letter Day

The engine started.

Yes, and I think it's starting to set in. It has been one year, two months, and 15 days since I last flew it, and the engine ran. But, who's counting?

The ice and snow is finally gone, so today C-Rod came out to help and try to fire it up. Hardly anything is safetied or tied down, I just wanted to see if the darned thing would run.


We tied it to my car, looked it all over and hit the button. The prop spun but no start. The EC3 controls both spark and fuel, so after a while I suggested that Charley spray in a little starting ether and see what that did.

I tried it again, and the engine lit and spun up! So, that must have meant the ignition part was working but there was something wrong with the fuel injector part.

We looked and looked, tore some wires fuel injector apart, checked pins, connectors, cables, wiring, all sorts of stuff. Still couldn't get the injectors to fire.


Then I said, "Let's see if maybe it's just the remaining magneto that is working and not the electronic ignition. Charley, spray some more ether and I'll try it with the mag off". It briefly roared and spun over fast as the ether fired up and tried to start.

But, I wondered if the magneto was really turned off. Maybe the mag was working and the ignition was not. "Charley, lets remove the plug wires and try it". So we pulled the Slick's wires, but the engine still tried to start on the ether.

"Charley, just for grins, pull the ALL the plug wires". So he did. To our astonishment, the engine STILL tried to fire up when boosted with the ether! Apparently, the high compression (9:1) pistons caused the either to diesel and ignite.

So, our initial supposition that the ignition must be working, was invalid. We decided to go back to the basics and make sure that the EC3 ECU was getting all the input it needed, and whattya know?

We found two wires reversed. It turns out the main power, from the "A" switch was being sent to the "B" side of the ECU, and vice-versa. Because of this the ECU, wasn't getting fed 12 volts.

I think we would have figured this out four hours earlier, if we weren't led astray by that goofy starting ether. After that was corrected it fired right up!



We ran it for about 15 minutes and seemed to be good. There is still a lot to be done, to be learned, and bugs to be ironed out, but it was a Red Letter Day!

Winter

Went to the hangar today, first time in a week. Too cold to work and enthusiasm was low. There is a ridge of solid ice, about 8" thick, all along the hangar door. If I hit the "OPEN" button, I would destroy the hangar door.

But hooray, tomorrow it's going to be in the 50s and the forecast is way above freezing for at least a week!

Maybe I can get the engine started next week. At least the oil in my new sump hasn't leaked out.