IO 360 Running rough

iceman · Post by **iceman** » Thu Apr 17, 2008 8:03 pm

Anybody out there with an IO 360 noticed that it runs rough when betwee 17 inches MP and lower. I don't remember this much vibration in the yoke at this MP and lower. WHen I'm in the pattern and throttling back below 2o Inches it starts to run rough and vibrates.... Anyone..... Help. I know it's a rough running beast on the ground and it's smooth as glass when at cruise and at 24 squared but Max prop and 18 inches and it's pretty rough and shakey......

Green Hornet · Post by **Green Hornet** » Thu Apr 17, 2008 8:22 pm

My 540IO did the same thing. My A & P replaced a couple of spark plugs and she purred like a kitten. They can be checked easily in a tester. At annual I changed all of them out so I new they were all the same age.

aero101 · Post by **aero101** » Fri Apr 18, 2008 8:52 am

Could also be partially blocked injector, injector pump, or FMU problem. If injectors haven't been cleaned for long time, would suggest an ultrasound bath (we usually do this every annual / 100hr on the Conti's) would be good place to start after checking plugs? Conti injector system very simple, but sensitive to proper adjustment. Good to have someone very familiar with system take a look?

MikeW · Post by **MikeW** » Fri Apr 18, 2008 9:04 am

Ice,

My IO 360 is a little rougher at the lower power settings too. My engine doesn't run "rough" but there is a little more vibration. I like the above ideas regarding plugs and fuel ingjection. Also ignition wires should be in good condition, no kinks or twists. These wires are pretty easy to break if twisted too much while screwing the wire back on the top of the plug.

Mikew

YELLOWMAULE · Post by **YELLOWMAULE** » Fri Apr 18, 2008 11:18 am

Check the above as stated. I've had a couple of clinkers on the plugs before and it cleared up some. Injectors are your #1 thing to check. Also, carefully look for fuel leaks in the spider, and injection lines themselves. Your looking for blue staining from leaks. Just for grins, grab your mags and see if they move.

These engines have a rough spot at about idle to 13-14" but nothing as rough as youv'e described. Suspect the fuel system first.
Good luck and let us know what you find!

Maule 9V · Post by **Maule 9V** » Fri Apr 18, 2008 3:40 pm

My IO-360 ran rough at low MP in the pattern. The idle mixture was set too rich.

Karl Hartlen · Post by **Karl Hartlen** » Sun Apr 20, 2008 2:09 pm

Mine was also running rough..quite rough actually. It turned out the injectors had crap in them and the mixture needed adjustment (too rich).

Out of curiosity, can you guys lean your IO-360 as per the Continental owner's manual instructions? If I do try and go 50 degrees rich of peak, at 2350 squared CHT runs awful close to 460!!

Karl

Maule 9V · Post by **Maule 9V** » Sun Apr 20, 2008 8:10 pm

Whatever I do, I try not to exceed 400 on the CHT. I do not lean beyond 100 degrees rich of peak unless I am going all the way lean of peak. Are you able to monitor all 6 jugs for CHT & EGT?

aero101 · Post by **aero101** » Mon Apr 21, 2008 8:56 am

Been my experience that with GAMI Injectors and monitor all 6 cyl EGT / CHT and the IO360's seem to do ok running lean of peak or 50D rich as well? The GAMI's do make huge difference in variation between cylinders!

Karl Hartlen · Post by **Karl Hartlen** » Mon Apr 21, 2008 2:49 pm

Maule 9V wrote:Whatever I do, I try not to exceed 400 on the CHT. I do not lean beyond 100 degrees rich of peak unless I am going all the way lean of peak. Are you able to monitor all 6 jugs for CHT & EGT?

Maybe the CHT guage is not accurate. My engine, full rich runs around 400 in the summer.... I've only got the single CHT probe on No. 3, so now I guess I'll run full rich until I get the guage checked, or get either the monitor for the 6 cylinders and/or Gamis..

Thanks,

Karl

iceman · Post by **iceman** » Mon Apr 21, 2008 6:06 pm

How much is a set of Gami's now?

Green Hornet · Post by **Green Hornet** » Mon Apr 21, 2008 6:21 pm

http://www.gami.com/gamijectors_order_form.html

Iceman , Price list above. Did you find out why your engine is running so rough?

iceman · Post by **iceman** » Mon Apr 21, 2008 10:14 pm

Nope not yet. Had to go to palm springs over the weekend,(Drove) and they were gonna look into it. I fly again tomorrow at 5 PM Will post after that if they find anything.

iceman · Post by **iceman** » Sun Apr 27, 2008 7:25 am

Plugs were cleaned and mixture checked... Seems to run smoother in the pattern and at lower man Pres..... You guys are right on....But of course maule pilots usually are!

Green Hornet · Post by **Green Hornet** » Sun Apr 27, 2008 9:17 am

Butch, Glad to hear it was an easy fix

after all the other problems you have been through with your aircraft. I Look forward to meeting you and the others at Johnson Creek this summer.

IO 360 Running rough

IO 360 Running rough

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