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I think I have a FI issue

AltonD

AltonD

Well Known Member
I have ~300 hours on the engine. First flight was August 2010.
IO360M1B SilverHawk FI.

Saturday, cold, ~35 degrees, I took off and saw #1 and #3 EGT got higher than normal, ~1400 degrees. I checked to be full rich. Fuel pressure was normal and the boost pump was on. No big concern, but this is different. Fuel flow was 15-16 gph. As I leveled out all was normal. I have a standard Van's fuel installation. I do have the red cube between the fuel servo and the spider. Left impulse coupled mag, right Light speed plasma 3.

Thoughts, suggestions?

(I know, 35 degrees is not that cold, but for a south Alabama boy, this is also NOT normal)

AND another thing, yeah, yeah, yeah, probably over instrumented. But, I am and I do see it. And for all of those going to tell me to use the search engine, I did. Searched Silverhawk.
 
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I'll take a stab at it.
It appears that your fuel flows are normal.
I suspect an ignition problem possibly one of your plasma coils or connections.
Having only one plug fire would cause such a condition. What makes no sense is that Cyl#1 and#3 are hot. If one connection on the coil is bad you would see #1 and #2 hot. An arching spade connector can cause temporary or intermittent ignition outages and is hard to spot unless you pull the connector off to look at it.
Something to look at while others come up with a better solution.
 
OK, bunch of questions.

1. Did you do a mag check in the air? You may have two dead plugs or failing to perform under load. Is this an EI with an unusual spark distribution system?

2. What happened going LOP? Dd you do this? If you have had some debris in the fuel system and it has partially blocked those two injectors, you would see them peak well before the others and run rough at a normal LOP setting.

3. I suspect as they have bitten me several times, the inlet gaskets. Or the inlet hose clamps?

4. Mixture cable length? I have seen as the engine rubbers sttle the cable gets pulled tighter at takeoff, and if it is at the end of travel it just pulls the mixture leaver back a fraction. maybe this is just enough to affect those two cylinders. So did you do any experimenting after you levelled out that is logged?

Do you have a data file from your EMS. Maybe I can help with that?

March 22-24, Ada OK, you could learn all this troubleshooting and a whole heap more. And no its not just about how to run LOP, (thats about 5% of the course).
 
RV10inOz said:
OK, bunch of questions.

1. Did you do a mag check in the air? You may have two dead plugs or failing to perform under load. Is this an EI with an unusual spark distribution system? Plasma on the top plugs, mag on the bottom. I did not do an airborne mag check. I will next time up. I replaced the EI plugs this past summer, IK24.

2. What happened going LOP? Dd you do this? If you have had some debris in the fuel system and it has partially blocked those two injectors, you would see them peak well before the others and run rough at a normal LOP setting. I did lean for peak, but I run ROP. I will check the peaks relatively close next flight.

3. I suspect as they have bitten me several times, the inlet gaskets. Or the inlet hose clamps? Not ruling it out, but it is a brand new factory engine that has performed flawlessly.

4. Mixture cable length? I have seen as the engine rubbers sttle the cable gets pulled tighter at takeoff, and if it is at the end of travel it just pulls the mixture leaver back a fraction. maybe this is just enough to affect those two cylinders. So did you do any experimenting after you levelled out that is logged? I will have to check.

Do you have a data file from your EMS. Maybe I can help with that?
YES, I will have to down load them. I departed on a 2.5 hour flight, they might be overwritten. will check.
March 22-24, Ada OK, you could learn all this troubleshooting and a whole heap more. And no its not just about how to run LOP, (thats about 5% of the course).
Click to expand...

Thanks for the reply. It gives me more to look and think about. I am liking the plug thing and maybe the mixture cable.
 
#3

Hi Alton,

I'm running the same set-up you are except with a Plasma II. The airplane just turned 300 hrs. coming home from LOE. Consider Dave Brown's suggestion #3 very closely. My RV 7 started doing something very similar. And it ever so gradually got worse. I finally put two and two together when I noticed it seemed more dramatic while taxiing than when airborne. If your egt spread between cylinders seems to be more dramatic at idle or partial throttle when engine vacuum is higher, my two cents is on Dave. I torqued the intake flange bolts before leaving for Weatherford and she was good as new.

Hope this helps,

Joe
 
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Thanks. I will get the cowl off this weekend and give everything a good look.

I believe there is a fuel strainer internal to the SilverHawk servo body. Can anyone tell me which plug to pull? I looks like it might be part of the fitting where the fuel supply attaches.

I was thinking fouled plugs (lower). But now that I think about it, the other two cylinder EGTs were also running higher than I expected. I might be that I have just never paid that close attention to them on take off.

Not a lot of help, but here is a dump from a takeoff in July:
(I will get a dump from the weekend flight after I get off work today).
Untitled.jpg


Datafile: http://adeweese3.home.comcast.net/~adeweese3/images/EGT_7-6-12.xlsx
 
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There are a lot of advantages in running LOP, besides the fuel saving, less stress on the engine and cleaner cylinders, valve gear etc.

One of the big ones is being able to diagnostics by comparing things from the ROP to LOP side.

This is a classical case of where this can help.

I know many of you guys are skeptical of an APS course and the cost, but right now is a prime example of where you make your money back quick smart.

Inlet gaskets are a real "quiet achievers" in the bug game. At 248 hours 5/6 gaskets, and at 496 hours I think 3/6 or something like that. So its a real issue.

Plugs, Auto's at 26-28 thou and Massive's 16-18.

I will send you my skype address, maybe we should have a chat one morning my time, evening yours. :) Maybe a 3 way hookup with Ernst ;)
 
Strainer in the Silverhawk servo ...

Yes, there is one. It's generally right behind the fuel inlet fitting. (My inlet happens to be on the aft side; many are on the front.)
 
Alton, Your problem sounds like a classic lightspeed coil failure. I have had the exact same issue. Do a mag check on the ground but watch your egt's closely and stay in each position at least 30 seconds. If you have number 1 or 3 or both go cold then you have a possible bad coil. It can also be the connectors to the coil which are prone to failure from vibration. Coil is a quick easy replacement. They are about 90 bucks. If you order from lightspeed they normally ship fast. I have a spare in Charlotte if you need one quickly and they can't get it to you.

George
 
Inlet gaskets are not easy to see all the way around, they decay slowly and sneek up on you and are not easy to see until you remove the pipe. Some times they show a crack visible from the outside, sometimes not.
 
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