Monday, December 16, 2013

Heater and fuel gauge gremlins

On my last flight back from taking the kids on a trip Disneyland I came back IFR, went through the clouds and popped out on top around 9k.  Over the Tehachapi's there were reports of turbulence and I wanted to stay out of the clouds as they pushed higher over the mountains.  ATC let me go to 13k even though I was heading west which was nice (west should be 12k or 14k) since I didn't have o2 with me.  The problem was at 13k and a cold front hovering over California, it was far far below freezing temps up there and my heater wasn't keeping up.  It's putting out warm air but not toasty warm like it should, and my wife and young son were cold in the back.  After some asking around on (amazing resource) about my Janitrol heater system, some things to check for:
  • Fuel pressure, should be at least 7 psi
  • Fuel injector nozzle - clean if that doesn't work, overhaul/replace
  • Spark plug - cleaning a plug with a rag and maybe a mild 3M pad is fine. If the plug was sandblasted its basically trash. That glazing on the ceramic is vital for proper ignition. And just as important as a clean (New) plug is on a Janitrol, a properly set gap is just as important. Verify its .156-.188
  • Check heater ducting for collapses and breaks
I took the plane into the shop and they cleaned the nozzle and the plug and we put them back in.  Fuel pressure was reading 9psi but on my test flight it still wasn't putting out great heat.  We ordered a new nozzle and plug so hopefully that will do the trick.  I also seem to be hearing more wind noise than normal so I wouldn't be surprised if there is a break in my vents somewhere though.  

Also my left fuel gauge sometimes drops off to zero. The fuel gauges have a circuit board on the back of the instrument panel just above the gauges.  The board reads the signal from the fuel sender and amplifies it for the gauge.  It sounds like I might have bad connection or a bad circuit board.  Beech wants $1500 for a new one which is clearly insane the parts couldn't possibly cost more than $15...  these guys have an after market but it will still be around $500 unless I can find another option... sigh...