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Hi, Leon...I had 28 gallons of fuel in the left
tank, and only 20 gallons in the right tank. (I was using the left tank). I
didn't fuel it completely, as I hadn't planned on going that far.
Fuel filter screen looked fine, and I drained some fuel
from each tank and from the gascolator....no visible water in the glass jar. I
will double check all electrical connections next, but the way the engine
sounded, it just seemed to be fuel starved. It runs fine now with normal water
temperatures. My fuel pumps are around 12 inches lower than my sump tank,
and the gascolator is the lowest point in the fuel system, and the fuel pumps
are about 3 inches above the gascolator/filter, so they do have to pull fuel
uphill, but only about 3 inches, in a hose that is about 6 inches long. (In
other words, the fuel pumps are about 3 inches above the gascolator and 6 inches
away from the gascolator).
One final thought.....my
aluminum sump tank in not vented. Seems we discussed this at length when I was
building this thing, and since the overflow is pumped into the sump tank, the
fuel might just be pumped right out of the vent. Take care. Paul
Conner
----- Original Message -----
Sent: Friday, February 11, 2005 1:34
PM
Subject: [FlyRotary] More wild ideas was
Re: [FlyRotary] Re: To Paul SOme diagnosis thoughts
Yo Paul,
OK, so it WASN'T the ECU! Not
electrical? I assume by now you have checked all electrical
connections?? Not the fuel filter etc? No water in the
fuel??
Vapour lock with EFI is pretty hard to get.
At 3 Bar pressure, the EFI pumps will see to that (as long as they don't
have to suck uphill). The only place you could get a vapour lock is
between the tank(s) and the lift pump, if you have one. As I have
no idea how your fuel is plumbed, I can only make wild
guesses.
So, ... SILLY question. How much fuel was
actually in the tanks?? Some aircraft are notorious for not being able
to access a fair percentage of what is left in the tanks at unusual
attitudes. ALL is OK in level flight, but on rotation,
or a steep (unbalanced) bank or side slip, the tank pickups are
uncovered. I've also come across problems of highly inaccurate fuel
guage(s). The only sure way is to dip the tank. I seem to remember
reading about a similar incident in a "Crash Comic" just recently. Even
the pros screw up occasionally (e.g., Boeing 307
Stratosubmarine!).
Got to get to the bottom of this - you are too
good a pilot and too nice a bloke to needlessly have a prang.
Cheers mate,
Leon
----- Original Message -----
Sent: Saturday, February 12, 2005 5:21
AM
Subject: [FlyRotary] Re: To Paul SOme
diagnosis thoughts was Re: [FlyRotary] Re: Microtech EFI and Tuning
Hi, Leon....I appologize for being late in
responding....I haven't had a chance to get on the computer. Yes, I
ran the engine yesterday. After inspecting the spark plugs (looked like new
with no evidence of rich soot or burned porcelain), I fired it up and it ran
great. Good idle, midrange, and 5300 rpm static instead of my usual 5200
rpm. I ran it WOT until the temps finally got so high that I had to shut it
down and watch the antifreeze burp out of the overflow on the surge
tank. Set up a cooling fan for a few minutes, then restarted the
engine and temps came down right away with the circulating of the
water/antifreeze through the engine and radiator.
As I mentioned in my
previous post, I am higly suspect that my problem was vapor lock/heat
related due to the two close together WOT engine runs I performed just prior
to takeoff. Normally, I always take off with temps around 160 to 180, not
220 or better. My temps normally come down in the climb, but at only 250
feet, I'm fairly confident I hadn't gotten much cooling air to the radiator
at WOT in the climb. I will keep you posted. Thanks again for taking
the time to help out. Paul Conner
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