New issue with new Lycoming engine--IO-360. . .

[cheetahdriver]

When I put the IO360 in my Cheetah I was like "I will NEVER have another carburetor again". However, I went through a fuel servo (RSA5) right after the first couple of test flights. It had been overhauled at a local shop and had some slop in it I didn't like. Did an exchange with a major shop and the difference was like night and day.

Since I seem to stay on the far right hand side of the bell shaped curve when it comes to flying (two fires, one engine failure, one loss of oil incident, all in under 1500 hours), I tend to be really cautious about my maintenance. Just because you are paranoid doesn't mean it isn't out to get you...

 

[Robster]

. . .well, a couple more issues with the new engine. A few days ago while landing, I pulled the power to idle on short final and discovered on roll-out that the left (new) engine quit. Taxied in on one and restarted the left engine after parking. Every time I reduced power to idle, it would quit. The mechanic stated that he made an adjustment to the (new) fuel servo, but thought the adjustment required for proper idle was extreme. At this point it's running fine at idle and throughout the power band. Stay tuned.

On another related note, during a flight last week the alternator on the left (new) engine started making a high-pitch whine in the intercom / radio system, which would vary with RPM. Mechanic determined that the alternator was bad and needed replacement.

Is it me or has QC at Lycoming and it's suppliers gone down lately? I don't recall having issues like this with previous factory engines. And the warranty process takes (literally) months for refunds to come through. Sign of the times?

 

[john_pifer]

subscribed.

 

[Robster]

UPDATE: Starter failure

. . . not to bash Lycoming, but I gotta call'em like I see'em. Just replaced. . .it was the newer light-weight model. . . .fourth accessory component failure since new. . . they don't make 'em like they used to or I got the one with all the components built on a Friday afternoon or Monday morning or during Oktoberfest. . . .

 

[A24]

Is anyone out there with a Lycoming IO-360? I was reading 2-year-old posts and was SHOCKED to see a couple owners having exactly the same problem as me - i.e., engine stumble when advancing the throttle during runup, the MP advances but not RPM or fuel flow. Then suddenly, the engine will rev to full RPM after several ins & outs of the throttle.
Fuel servo diaphragm? Does anyone have a result that solved this problem? I also wonder if it might be giving me a lean condition during flight in 1 or 2 cylinders...

 

[Robster]

I no longer fly the aforementioned aircraft--it was sold and we fly a different model now. The fix for me was replacing the fuel servo. Call Lycoming's tech support and see what they say--their sub-component vendor's have QC problems.

 

[Cujet]

Originally Posted By: A24
Is anyone out there with a Lycoming IO-360? I was reading 2-year-old posts and was SHOCKED to see a couple owners having exactly the same problem as me - i.e., engine stumble when advancing the throttle during runup, the MP advances but not RPM or fuel flow. Then suddenly, the engine will rev to full RPM after several ins & outs of the throttle.
Fuel servo diaphragm? Does anyone have a result that solved this problem? I also wonder if it might be giving me a lean condition during flight in 1 or 2 cylinders...


An injected engine with lean cylinders is not likely to be the fuel servo. The fuel is metered into one hose. Then split amongst the cylinders via a fuel manifold (spider) devoid of any restriction. The injectors themselves are the restriction.

In other words, all injectors receive the same fuel pressure. The higher the pressure, the more the injectors flow. Matching injectors does help keep the mixture correct for each cylinder.

I have GAMI injectors. There are minor differences in flow rates between the cylinders. This leads to smoother operation, slightly better economy and higher overall personal happiness!

 

[Cujet]

Originally Posted By: Cujet
Originally Posted By: A24
Is anyone out there with a Lycoming IO-360? I was reading 2-year-old posts and was SHOCKED to see a couple owners having exactly the same problem as me - i.e., engine stumble when advancing the throttle during runup, the MP advances but not RPM or fuel flow. Then suddenly, the engine will rev to full RPM after several ins & outs of the throttle.
Fuel servo diaphragm? Does anyone have a result that solved this problem? I also wonder if it might be giving me a lean condition during flight in 1 or 2 cylinders...



An injected engine with lean cylinders is not likely to be the fuel servo (correction spider) . The fuel is metered into one hose. Then split amongst the cylinders via a fuel manifold (spider) devoid of any restriction. The injectors themselves are the restriction.

In other words, all injectors receive the same fuel pressure. The higher the pressure, the more the injectors flow. Matching injectors does help keep the mixture correct for each cylinder.

I have GAMI injectors. There are minor differences in flow rates between the cylinders. This leads to smoother operation, slightly better economy and higher overall personal happiness!


I can't edit the above. But what I meant to say was "SPIDER" not servo.

The "throttle body" is an RSA-5 fuel servo. I was thinking about the spider (which is known as a flow divider or spider) on top of the engine.