Hi all,
I have read numerous threads on rough idle when engine is hot after landing etc. and I thought I'd share how we solved our issue. As background we previously built/flew and later sold an RV7 with AFP IO360 and never had any issues with idle or hot starts etc., but we recently bought an RV6A with a Bendix FI on a Lycoming IO320. The plane needed some TLC to bring it up to par. It idled horribly and we tried many things to no avail, but we finally checked every fuel line fitting from the tanks to the engine and in the process found about 3 of the AN fittings slightly less than tight...not loose, but easily turned 1/8 of turn to snug them up. That was allowing a very slight amount of air into the fuel which would boil out at higher temps. There was no wetness at the fittings, but the tell tale blue dye of evaporated 100LL was present when rubbed with the fingers.
That was our problem as our idle roughness with a hot engine disappeared and now it idles normal. Hope this helps someone to start with the simple stuff before diving into new injectors, spring changes, etc.
Don
Colorado
I have read numerous threads on rough idle when engine is hot after landing etc. and I thought I'd share how we solved our issue. As background we previously built/flew and later sold an RV7 with AFP IO360 and never had any issues with idle or hot starts etc., but we recently bought an RV6A with a Bendix FI on a Lycoming IO320. The plane needed some TLC to bring it up to par. It idled horribly and we tried many things to no avail, but we finally checked every fuel line fitting from the tanks to the engine and in the process found about 3 of the AN fittings slightly less than tight...not loose, but easily turned 1/8 of turn to snug them up. That was allowing a very slight amount of air into the fuel which would boil out at higher temps. There was no wetness at the fittings, but the tell tale blue dye of evaporated 100LL was present when rubbed with the fingers.
That was our problem as our idle roughness with a hot engine disappeared and now it idles normal. Hope this helps someone to start with the simple stuff before diving into new injectors, spring changes, etc.
Don
Colorado
