« Posts tagged EFIS

Zero Sum

6 hours.

I spent a whole lot of yesterday doing various things, which is the surest way to feel like I got nothing done.   I had two goals: Fix the idle stumble and run down that AP engage joystick wire issue.

The first part was almost easy.   I set the mag timing to 25 degrees per the engine data plate.  I’m getting to be an old hand at setting mag timing.  I got them both firing in sync, then made the idle richer by a couple of flats of the adjustment linkage, per the AFP manual.  Sure enough, that cured the off-idle stumble and my CHT’s and EGTs dropped noticeably.  But there was still a rough idle, so more adjustment needed to happen.

The manual says that adjusting the idle is done with the engine running.  The problem with that is twofold: One, working near a spinning prop scares the crap out of me.  I haven’t had the training to do so safely.  Two, because of the orientation of the throttle body, the idle linkage is on top, between the throttle body and the engine case, and the only way to get at it is by reaching past hot exhaust pipes.  Even if I did have the stones to crawl under there with the prop spinning, I can just see burning my forearm on the #1 pipe and yanking it back into the arc of the prop.  No thanks.  I did my idle adjustments with the engine off.

With Mike as the casual observer, it appeared that my idle was too rich, because there was a bit of smoke coming from the pipes when I was idling and the idle was definitely a bit rough.   This is caused by multiple symptoms, but a too-rich mixture is the first and most obvious culprit.

The manual also says that the best way to adjust the idle is to leave one of the jam nuts “just snug” and turn the block one flat at a time.   Well, yours truly interpreted “just snug” as “don’t touch” and after a couple of turns of the block, the left-hand rod end bearing snapped off at the jam nut.

BrokenBearing

So now I have to find/buy a LH thread #3 rod end bearing and I can get back to business.

As for the other stuff, I did chase down the AP engage wire.   Turns out I have to figure out a way to do some kind of voltage differential and use the MGL script editor in order to remote-control the EFIS to engage the autopilot.   A simple “Hey, I’m Grounded” won’t work.   This will take a minute to work out the logic, but I’ll email Matt at MGL and see what he says.

Also, Owen and Ron got the racing scales, so I can do weight and balance.    This gets done first thing today, because I need to return the scales ASAP.   It’s   I’m just hoping the W/B comes in as expected.

I also fiddled about with the wheel pants, but that’s not high on the priority list right now.

Equal parts forward and back.

6 hours.

One of these days, I’ll move forward without moving backwards.  Today I had to dismount the EFIS in preparation for taking it to MGL Avionics.   Apparently the OAT module is fried.  I tried it with a new probe last week, no dice.   Maybe, if I’m lucky, I’ll be able to drop it off tomorrow on my lunch hour.   Other than that annoyance, I got the tailwheel hardware primed, something I should have done long ago, and I got my spark plugs torqued in.   But now, for some mysterious reason, the tailwheel steering chains don’t reach their mounting points on the rudder anymore.   It’s possible I had the steering link on upside down/backwards, which would have accounted for the missing 3/4″ of chain necessary to bridge the gap between what I need and what I’ve got.   Looks like I’ll be ordering another set of tailwheel chains.  Grumble.

Anyway, once I get my EFIS back from the shop, it’ll be time to prepare the engine for first start.

On another note, I’m progressing nicely in my tailwheel training.   We flew from Torrance to Hawthorne, where I did 8 landings, unassisted.   Apparently I CAN land a Citabria in 3-point attitude.   At least when the wind is coming at me and I set up the approach right.

A Fix and Some Finishing

7 hours.

Although the last three shouldn’t count because I spent them fixing something I should never have had to in the first place.

20130728-192738.jpgThat little corner of aluminum is the bane of my life.    Since I put the wings on, I’ve caught it on shoes, shirts, and finally, the belt on my jeans.   When this happens, it bends.   This time, I bent the crap out of it, so badly, that I had to remove the fasteners on the skin, peel it back, and hammer it flat again.  The light makes it look worse than it is, but it’s still pretty bad.   Fixed now, though.

 

20130728-192751.jpgThe day wasn’t all bad.   I got the fuel pump overflow plumbed.   I used some of the tubing I had from the MAP sensor install to create a flexible link between the output of the fuel pump to the hard line shown here.   The engine wiggles.  The aluminum tubing doesn’t.   I need a flexible line between the two.

20130728-192805.jpgThe fuel sensors concerned me for a minute.   When I connected the wings, I had some little extra wires that I thought I’d run for spares.   I guess this is why you label things.   After some pondering, I realized these were the fuel level sender wires.   Duh.  The good news is that I didn’t have to do any splicing and apparently I cut them to the right length.   A couple of connectors later and I had fuel level, which was, of course, zero.

No luck on the OAT sender though.   Either my EFIS or the probe is bunk.   OAT reads a steady 32 degrees F.  Have to contact MGL for a new one.

Avionics Install (almost) DONE!

4 hours.

Sweet FA got done over the weekend (New Years, hangover, etc, etc.), but today I finished wrapping and securing various wires, as well as rerouting the starter ground in a bundle instead of floating around all by its lonesome.

Only two things left to do, really, and that’s to install the OAT probe and reconnect the IOX when it comes back from MGL in a couple of weeks.  For now, i’m not sure whether or not to start the baffling or the FWF sensor wiring.