Engine Sputtering After Starting While Hot

Joined
Aug 18, 2020
Messages
5
Location
Atlanta
Hey everyone! I have a Decathlon with a Lycoming AEIO-320-E2B... after hot start procedures, the engine sputters during taxi until takeoff. Runs fine while flying, runs fine after landing. It’s just that time after a hot start up until takeoff. Any ideas? Thanks in advance!
 

Bob Turner

Well-known member
Joined
Apr 4, 2018
Messages
1,077
Define sputter. They all have this funny loping tendency when hot and idling - at least the injected 320s abd 360s
 
Joined
Aug 18, 2020
Messages
5
Location
Atlanta
Define sputter. They all have this funny loping tendency when hot and idling - at least the injected 320s abd 360s
Yea, after starting it while hot, it sputters even running it at 900-1000rpm...there are even moments it sounds like it’s going to die, (never has)... engine performs well after takeoff and sputtering is gone when I land and taxi.
 

Bartman

Administrator
Staff member
Joined
Mar 27, 2018
Messages
1,359
Location
New Jersey, USA
saw your post on Facebook, looks like you got it straightened out.

hot engine after restart continues to cause vaporization of the fuel in the feed lines at low RPM's which makes the engine sputter when taxiing. As RPM's and fuel flow rates go up, the vapors are cleared and the engine runs smooth. you can probably make the argument that the higher fuel flow rate adds cooling to the components that make up the fuel system so the fuel isn't able to vaporize. You can probably also make the argument that the fuel is flowing more quickly so it doesn't have time to warm up before being injected into the engine. And you're both probably right.

I learned something reading that thread, figured it was worth posting the info here. :)
 
Joined
Aug 18, 2020
Messages
5
Location
Atlanta
Wow! Thanks you guys are so awesome! I’m probably going to change my intake gaskets and replace hardware anyway to rule out a potential induction leak. Mine as well, cheap investment!
 

BB57

Well-known member
Joined
Feb 20, 2020
Messages
163
That service instruction more or less outlines what folks with AEIO and IO powered Citabrias and Decathlons normally do to address the issue.

In short, I do a run up after taxiing to the departure end of the runway, and while it may run a bit rough taxiing at 1000-1200 rpm it's always smooths out at 1800 rpm. It never hesitates or stumbles on take off, but I'll usually hold the brakes until it comes up to full static rpm just to be sure.

In other related news, we flew down to Cape Fear today to cruise up the beach and get pictures of the Oak Island lighthouse. There was no rough running following a hot start after 30 minutes on the ground at KSUT.

That means fall is officially here.
 

Bob Turner

Well-known member
Joined
Apr 4, 2018
Messages
1,077
Could not open it on the iPad. And here I thought they all did that. Mine idles at a grand with leaning, and only "lopes" when it has been running for a while - like taxiing in on a hot day.