[April 23, 2016]

One issue which I have noticed lately is I have an issue of running any leaner than peak after a climbout and the engine CHT's are hot. One theory that makes sense to why this is occurring is because the fuel is boiling in the lines and vaporizing. A suggestion was to insulate the fuel lines further with an extra layer of fire sleeve. I decided to tackle the fuel line from the fuel servo the the fuel divider. This is the short length contained within the baffles/plenum.

And the backside of the run passing behind the engine.

And finally terminating into the aft portion of the fuel servo. Total length was about 3'.

Another possible culprit was the supply into the fuel servo. I am not going to tackle this hose yet, I want to take a somewhat scientific approach to this and only change one thing at a time.

I purchased 4' of 3/4" inner diameter (ID) firesleeve from Ebay for a little under $5/foot. Aircraft Spruce was charging about double this.

The quality of this firesleeve seemed to be quite high. I was very impressed with it and its durability.

Here is the final product of my days work.

Speaking of issues with my airplane, I am also battling an issue of my autopilot falling out of GPS Steering mode (GPSS) with my EFIS. It follows my Garmin 430W perfectly, but for some reason, it falls out with my GRT EFIS. GRT says it's a AP issue, TruTrak says it's an EFIS issue. Lovely! To eliminate some of the potential causes, I made a ARINC loopback plug for the GRT Arinc 429 box.

The wiring was super easy - pin 1 to pin 5, and pin 2 to pin 9.

Under the EFIS Maintenance menu, and ARINC Status sub-menu, there is a loop test option. We successfully transmitted and received 31 frames. So everything seems right with the ARINC module.

This is how my EFIS is wired - the ARINC module is attached to my MFD. When I called up GRT, they recommended I try moving the ARINC module to the PFD as the inter-display link might be getting overrun causing packet loss.

This is the method they said to try.

Luckily moving some of the wires around between EFIS's was pretty simple.

Time for a flight test of both the GPSS issue and possible fuel vaporlock issue. Today was the perfect day to test. The winds were gusty on the ground keeping most people grounded.

On the climb I tried to get the CHT's elevated.

The Autopilot was doing all of the heavy lifting. The thing didn't miss a beat all day. No matter what I tossed int he flight plan on the EFIS, the AP tracked it perfectly. I think I finally got this issue licked.

Traffic was also working a lot better.

This was the highest I was able to get he CHT's up to. I was able to lean back more than I usually am able to. I don't know if the extra firesleeve made a different yet. Time will tell.

Back on the ground I yanked the Garmin 430W out of the panel. I am going to drop it off at Lancaster Avionics for them to send it into Garmin to be fixed, then I am going to sell it and replace it with a GTN650. While there is nothing wrong with the 430W, it is older technology which is still demanded a high resale price. I figure I might as well sell it while the demand is high for the unit. With it coming back fresh from Garmin with a 6 month warranty, I don't see why it won't move fast. I have a GTN650 on it's way from Stark Avionics. They were able to offer me a great price - roughly 8.5% less than any other avionics reseller was offering!



Last Modified: May 19, 2024