Hot Starting Fuel Injected Engines

"Corky Scott" wrote in message
...
On Fri, 17 Oct 2003 03:40:48 GMT, "Casey Wilson"
wrote:


Here's the way I was taught to hot-start the 180hp Lycomings in the
Skyhawk:
Follow the check list procedure for a normal (first time today)
start.....

That is:
Advance throttle 1/4 inch
Mixture to idle cutoff
Master switch on
Fuel pump on
Push in mixture control to see positive fuel flow on the gauge
Mixture to idle cutoff
Fuel pump off
Crank the engine
Shove the mixture control to full rich when the engine starts
Adjust throttle for 1,000rpm

It works for me. Even when the OAT is 3-digits



Casey, you just described what the Skyhawk POH says is the "cold
start" procedure.

The POH specifically says to eliminate the use of the fuel pump for a
hot start.

Did you read that out of the POH, or is it something taught to you by
your instructor because he/she found it worked better?

The latter. After ten frustrating minutes sitting at the fuel pump after
a couple of hours of dual instrument work, I was ready to get the towbar out
and drag the ^%$#(@% airplane back to the tiedown. All the time the
instructor was sitting in the right seat, not saying a word.
Finally, he said, "Had enough?"
"%&&#)&@&&, right," says I.
"Use the checklist for a cold start."
Less than a minute later we were rolling across the ramp. He told me
later that he let me get frustrated to make the lesson more firm.
This, by the way, is the only deviation from the POH I've ever used
intentionally.

"Casey Wilson" wrote in message ...


Did you read that out of the POH, or is it something taught to you by
your instructor because he/she found it worked better?

The latter. After ten frustrating minutes sitting at the fuel pump after
a couple of hours of dual instrument work, I was ready to get the towbar out
and drag the ^%$#(@% airplane back to the tiedown.

The book starting procedure for my (pressure carb'd lycoming) never worked
either (especially when warm). My former mechanic (who never read a book
or checklist in his life, generally one of his failings), never had a problem starting
hot or cold. So I asked him what he did, and that's what I use for everything:

1. If cold (boost on, prime, boost off).
2. Full Rich, 1/4" thorttle.
3. Crank (two blades before the mag comes on if cold).

Always worked. This is neither the book hot start or cold start procedure
(both of which call for leaving the boost pump on).

"Paul Sengupta" wrote in message . ..

We stop the engine by moving the mixture to ICO. Now all
the books, etc, say that this is so that there is no fuel left to
ignite if there's a live mag, so the engine won't start. Now if
an FI engine leaves fuel ready for the next start, then a) it's
more dangerous if there's a live mag, and b) would switching
off the ingition be any different in this case? Would it leave
the engine too flooded?

OK, so the engine is running and you switch off the mags, then the
mixture.

The air/fuel that is left in the induction system would be real close
to an ideal mixture for a "hot-start" seeing how it was working so
well when you flipped off ignition. The additional fuel added from
the hard lines would probably initially enrich the mixture, but would
be just as likely to help keep the right amount of fuel in the system
for a longer period of time.

With an ICO shut-down, initially there is no fuel, then gradually goes
to too lean, gets richer, then leans out again as the fuel evaporates.

The trick for an injected Lycoming hot start is to try the first one
without adding any fuel, then add a little. Too lean is easily
remedied, too rich/flooded is more problematic to clear.

TC

Well said. A lean mixture is easier to richen and ignite. Rich is a
pain.

The trick for an injected Lycoming hot start is to try the first one
without adding any fuel, then add a little. Too lean is easily
remedied, too rich/flooded is more problematic to clear.

TC