Hot weather ground operations

[rvdave]

From Michigan but currently flying in Florida and noticing after landing in hot temps and especially after hot starts and taxiing I?m getting rough running that I haven?t noticed before since I?ve only been flying for a short while. Seems to me to be hot fuel since after airborne and normal airflow problem seems to go away. Is this common for hot weather ops and fuel injection?

[lr172]

Pretty common with Bendix FI. Usually seen shortly after landing and more so after starting with a heat soak. Symptoms increase with the ambient temps in the summer wx. Seems some configurations fair better than others though.

Larry

[Auburntsts]

I have the AFP FI system (FM 200) and haven't noticed the issue you are describing.

[Phil]

Pretty common here in Texas. The taxi-in is noticeable after a few minutes on the ground. After it’s shut down and heat soaked, it’s even worse.

The AFP fuel bypass valve helps with the restarts and makes the stumble less noticeable. But on seriously hot days, it doesn’t always fix the stumble as there’s just too much heat for the small amount of fuel needed to idle.

Until a high volume of fuel runs through those lines and cools them down, the stumble persists during hot ground ops. Once the rpms come up and the fuel starts flowing in a higher volume, there’s enough thermal mass in the fuel to make the engine operate smoothly.

... then, of course, once you’re flying you’ve got the added cooling of the air on the lines.

What you describe is something we see here pretty frequently in our local -10 fleet.

[jeffkersey]

I whave see similar symptoms on my injected I0-360 when really hot...

[bruceh]

I've given up trying to idle my IO-320 at less than 1000 rpm when heat soaked.

It idles fine at lower RPM's when the engine isn't heated up.

[dmaib]

Very common on all the -10s I've flown here in FL. I almost always open my oil door after shutting down on a fuel stop or a lunch break to try and let some of that heat escape.

[snopercod]

Have you tried leaning?

[rvdave]

It does seem to help a little with leaning but not to the point where it will run smoothly. I do have the purge valve and am experimenting with that to push cool fuel before taxi.

[painless]

Hot weather ops?? What?s that? (As I get ready to fire up the snowblower..... again!)