Hot starts. Again !

[OR75]

i know it has been covered again and again and everyone here has a opinion, a technique or a secret on how to make it work.

What has worked for me so far was to not touch anything. ( no touching of the controls, fuel pump or anything) When it comes alive, push the controls forward. Done.

if it does not work at the first crank, I know I am in for a struggle and a lot of stress on the battery and the starter but eventually it will start.

This time it did not. After about 30 mn of trying to start it, i gave up and opted to have a cold start the next day.

next day, no start.

after some back and forth and trying several combinations that I won't detail here, fuel started flowing from the fuel drain hose. Probably about a quart.

After thatbthe engine started almost normally and ran just fine.

obvious the engine was flooded. I wonder what all of a sudden made the engine get sick of the fuel ?

Anyone experienced that before ?

[N201MKTurbo]

Stuck sump drain. The fuel probably cleaned it out. The sump drain is a one way valve in the right angle fitting in the bottom of the air box in the bottom of the engine. It closes when the engine is running and should open when there is no longer negative pressure in the intake manifold, allowing the excess fuel to drain out.

[OR75]

Makes sense

What do you think may have cause it to stay closed ?

[OR75]

Could not locate the fuel drain valve on the io-360

Parts manual . Are you sure there is one ? Is not it a simple drain pipe ?

[N601RX]

It is a modified AN fitting that Mooney makes. They take a 90deg AN fitting and machine out the inside and place a ball in it with a pin to hold it in. Lycoming also makes a straight version of it. It screws directly into the bottom of the engine.

If it sticks open the engine will lope and run rough,

Picture is here

http://www.donmaxwell.com/publications/MAPA_TEXT/External_Hoses/FITTING6.JPG

[N201MKTurbo]

Makes sense

What do you think may have cause it to stay closed ?

Camguard

[OR75]

i do not use camguard.

i have seen that fitting. it is right above the trough in the exhaust shroud.

i guess mooney did not want to use the Lycoming drain valve and opted for the 90° version to save space ?

[triple8s]

Operating LOP will damage the ball and make it stick closed.

[tomn]

Stuck sump drain. The fuel probably cleaned it out. The sump drain is a one way valve in the right angle fitting in the bottom of the air box in the bottom of the engine. It closes when the engine is running and should open when there is no longer negative pressure in the intake manifold, allowing the excess fuel to drain out.

I need to go look for this on mine and I'm not having any issue with it but how would this ball being stuck cause the engine to run rough if it is fitted to the bottom of the air box? Or is it in the intake system after the servo?

[N201MKTurbo]

I need to go look for this on mine and I'm not having any issue with it but how would this ball being stuck cause the engine to run rough if it is fitted to the bottom of the air box? Or is it in the intake system after the servo?

 

Yes, it is in the intake system after the servo. It will allow unmetered air into the intake manifold. It is a small leak, so it will only have a significant effect at idle.

[tomn]

On your hot starts - I struggled with this for a while trying every technique I could find. I finally had the servo overhauled after I started seeing EGT fluctuations at altitude. The hot start issue was solved with the servo OH. Its still hard to start hot but is manageable.