On May 11, 3:28 pm, Newps wrote:
Lycoming seems to be the worst to start in these situations. I have an
IO-520 and have similar problems. First off the vapor lock is not in
the spider lines sitting just above the engine. The vapor lock is in
the engine driven fuel pump. Mixture at cut off and run the aux pump
for about a minute. This will run cool fuel thru the engine driven pump
and then back to the tank. The last five seconds that you are doing
this push the mixture control in and leave it there. That allows the
fuel to now go into the spider lines. Throttle all the way out. Start
cranking, while slowly advancing throttle. About 1/2 way in engine will
fire and run. Adjust throttle for about 1000 rpm. If engine wants to
stumble because you let off the starter at the wrong time bump the aux
pump for about 1 second at a time. Never had to do this more than twice
to keep engine running. I very rarely have to bump the pump and get
successful starts about 95% of the time when the engine is hot.


That sounds a bit different - mixture rich for a hot start?? Is this
because it's a IO520??? I am using a IO360 in an Arrow, if that makes
any difference..

Now reading this I remember when I was a passenger in a Twin Comanche
a few times and the engines on that kept trying to die just after
start and the pilot had to give it a blast of boost pump a few times
until it stabilised..