Installing SureFly, wierd issue with rough idle and hard starting

[cctsurf]

12 minutes ago, msh9 said:

With that said, today, the mechanic tried swapping out the ignition harness with another one. SureFly works beautifully now.

I'm SO Glad you got that figured out!  I was hoping we would get a conclusion to this.  Hope it serves you well for LOTS of hours flying!

[Will.iam]

1 hour ago, msh9 said:

ALRIGHT,

sorry for the delays. First, thank you all for the many suggestions. The suggestions to watch the engine monitor were good; incidentally the plane was also having a JPI EDM 900 installed while this was being done.

 

With that said, today, the mechanic tried swapping out the ignition harness with another one. SureFly works beautifully now.

Looks like the issue was the new harness we previously ordered to go with the SureFly was setup for right rotation instead of left. Two cylinders were swapped and the leads mislabeled. Very frustrating that it took us this long to figure out and partly because we assumed the new harness we ordered was good. That's what we get for making assumptions. In any case, that's getting returned and hopefully we'll have everything back together soon.

 

Thanks again everyone!

You couldn’t just change the plugs wires to the correct spark plugs, you had to buy another harness?

the reason i asked is that the maggie harness you can change out individual lead wires so changing the firing pattern on the cap would be just swapping positions. 

[47U]

1 hour ago, msh9 said:

Looks like the issue was the new harness we previously ordered to go with the SureFly was setup for right rotation instead of left.

Kudos to you and your mechanic.  How frustrating when there’s an error from the manufacturer.  

I needed to get a Slick-style harness when I replaced my left mag with a SureFly.  It was a special order.  They transposed the part number and sent the wrong harness.  Finally… got that straightened out.  Then I thought, the right harness looks pretty ratty in comparison (after 30+ years), so I order a new Bendix-style harness from the same company for the right mag.  I looks great, but the plug markings are the same as the left harness… i.e., two “B-1”, etc.  I ended up putting SureFLy mag on the bottom plugs and the right mag on the top plugs.  The plug wire routing worked out ok, but if I were paying someone to maintain my Mooney, I’d not be happy.  Or, maybe I wouldn’t even be aware? 

[msh9]

19 minutes ago, Will.iam said:

You couldn’t just change the plugs wires to the correct spark plugs, you had to buy another harness?

the reason i asked is that the maggie harness you can change out individual lead wires so changing the firing pattern on the cap would be just swapping positions. 

Perhaps, I wasn't on the phone with New Horizons. Decided to return the harness we bought and they would sent a new one. No new harness being purchased either way.

[Will.iam]

6 minutes ago, msh9 said:

Perhaps, I wasn't on the phone with New Horizons. Decided to return the harness we bought and they would sent a new one. No new harness being purchased either way.

Thanks for the heads up as my A&P will be putting the maggie harness on next week with a surefly so I'll make sure he double checks firing order of the leads. 

[kortopates]

Looks like the issue was the new harness we previously ordered to go with the SureFly was setup for right rotation instead of left. Two cylinders were swapped and the leads mislabeled.

The 4 cyl Lycomings wortk with 2 different harness configurations. When they left the factory, the Lycoming harness set up had each sides mag fire the bottom plugs on that side and the tops on the opposite side. Almost every other engine does the opposite, with the mag firing the top plugs on its side and bottom on the opposite side; the conventional setup. There are aftermarket harnesses for the Lycomng 4 cylinders that do use the conventional setup rather than the original setup. Everything is fine when you replace the entire harness, but if your replacing just one of the Mags, you need to make sure its compatible with the other side - Lycoming or conventional.. I'd bet that was the real issue.   

[FLYFST]

ALRIGHT,
sorry for the delays. First, thank you all for the many suggestions. The suggestions to watch the engine monitor were good; incidentally the plane was also having a JPI EDM 900 installed while this was being done.
 
With that said, today, the mechanic tried swapping out the ignition harness with another one. SureFly works beautifully now.
Looks like the issue was the new harness we previously ordered to go with the SureFly was setup for right rotation instead of left. Two cylinders were swapped and the leads mislabeled. Very frustrating that it took us this long to figure out and partly because we assumed the new harness we ordered was good. That's what we get for making assumptions. In any case, that's getting returned and hopefully we'll have everything back together soon.
 
Thanks again everyone!

Also consider setting the spark plug gap to the lower standard value for your engine on the plugs fired by the mag and to the larger gap on the plugs fired by the Surefly. I just installed a Lycoming EIS and Slick Mag combo on my IO-360-A3B6 and got that recommendation to deal with the large rpm drop I get on the EIS only during run-up because all my massive plugs are gaped to the lower, standard gap value recommended. I have not made the change yet so cannot report how well or not it works on my engine.


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[cctsurf]

4 hours ago, FLYFST said:

Also consider setting the spark plug gap to the lower standard value for your engine on the plugs fired by the mag and to the larger gap on the plugs fired by the Surefly.

I really don't want to be rude, but have you read any of the previous posts in this thread?  This has been discussed in depth.

[carusoam]

PK,

That sure is eye opening…

I’ll try to remember that one…. 
 

 

Best regards,

-a-

[Browncbr1]

on my left bank of cylinders, I swapped the upper and lower leads so that the surely fires all bottom plugs with a larger gap.  I also put a blue "B" on all the bottom plugs just to signify that they stay on the bottom because of the larger gap.   

[FLYFST]

on my left bank of cylinders, I swapped the upper and lower leads so that the surely fires all bottom plugs with a larger gap.  I also put a blue "B" on all the bottom plugs just to signify that they stay on the bottom because of the larger gap.   

What results did you get? What is your run-up rpm drop like? Any noticeable change in takeoff or cruise performance?


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[Browncbr1]

1 minute ago, FLYFST said:

What results did you get? What is your run-up rpm drop like? Any noticeable change in takeoff or cruise performance?


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I get about 30 rpm drop on both the surefly and the slick.  I think the slick doesn't have enough spark to do as well on the bottom plugs that are getting blasted by the injector.   It's been a long long time since I ran this engine the other way.  I think timing advance and sync is most important.   I just felt that a stronger spark on the bottom is better.  i have no data to back it up.

[FLYFST]

I get about 30 rpm drop on both the surefly and the slick.  I think the slick doesn't have enough spark to do as well on the bottom plugs that are getting blasted by the injector.   It's been a long long time since I ran this engine the other way.  I think timing advance and sync is most important.   I just felt that a stronger spark on the bottom is better.  i have no data to back it up.

Thank you! I’m only 7.7 hours into the break-in process and getting rpm drops of 140 on the EIS and 70 on the Mag, with massive plugs gaped at the lower standard recommended gap. Maybe as the break-in continues the numbers will change some more. I do plan to change the gaps and mark the EIS leads as you did and determine what that results in.


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