Mark89114 Posted September 4, 2017 Report Share Posted September 4, 2017 Went to fly my ovation today and on start up, above cylinders didn't fire.....worked throttle and mixture in and out a bit and eventually they came alive.....didn't go flying. I did do a high power run up and that was normal. Called my mechanic and going to look at it tomorrow.....our thinking is something in the fuel spider maybe? Quote Link to comment Share on other sites More sharing options...
DVA Posted September 4, 2017 Report Share Posted September 4, 2017 Odd. What convinced you that one side of your engine was not firing while the other side was? 1 Quote Link to comment Share on other sites More sharing options...
Mark89114 Posted September 5, 2017 Author Report Share Posted September 5, 2017 No EGT temps....guess I should have included that detail on original posting....and it was vibrating badly. Quote Link to comment Share on other sites More sharing options...
carusoam Posted September 5, 2017 Report Share Posted September 5, 2017 1) Fuel: I don't believe the fuel spider is split in half like that... is it? 2) Ignition: Thinking about how the mags could be causing a challenge... may be related to mag timing(?) 3) Air: See anything odd around the air intake? Anything blocking the exhaust? Can you send data to Savvy? This Sounds really peculiar. PP thoughts only, not a mechanic... Best regards, -a- Quote Link to comment Share on other sites More sharing options...
jaylw314 Posted September 5, 2017 Report Share Posted September 5, 2017 How are Continentals arranged in terms of spark plugs? In Lycomings, the spark plugs from each mag go to left-top/right-bottom or left-bottom/right top, so that could account for one side not firing with with oil-fouled plugs on the bottom, since only one mag has an impulse coupler. However, I have no idea if any of that applies to Continentals... Quote Link to comment Share on other sites More sharing options...
Raptor05121 Posted September 5, 2017 Report Share Posted September 5, 2017 Did you open the cowling and check for any visual discrepancies? 1 Quote Link to comment Share on other sites More sharing options...
StevenL757 Posted September 5, 2017 Report Share Posted September 5, 2017 Mark, You most-likely have (or did have) oil-fouled plugs on the right side side firing, but not as well as the three on the left. Over-priming (Hi or Low boost pump running excessively) could also cause this. During your run-up (given the sucking and blowing of fuel and air repeatedly) you may have cleared the condition and it may have been ok to launch. It's possible - although doubtful - you have a magneto issue. This is the reason we do thorough run-ups; so given you weren't aware of what was happening, you made a good decision in this instance to check things out before launching again. A few questions if you don't mind... 1. What is your priming routine (do you follow the checklist/AFM, or do something different)? 2. What has your oil consumption been in the last 50-100 hours, and how often do you do oil changes? 3. Total hours on this engine? 4. Are you running lean or rich of peak in cruise? 5. Any engine or starting issues prior to this - similar or not to this latest incident? Steve Quote Link to comment Share on other sites More sharing options...
StevenL757 Posted September 5, 2017 Report Share Posted September 5, 2017 18 hours ago, Mark89114 said: No EGT temps....guess I should have included that detail on original posting....and it was vibrating badly. They were probably firing to the point where numerical values were indicating, but not enough to show on your bar graphs (if you have an EDM7xx, 8xx, or 9xx, or other graphical EM). Quote Link to comment Share on other sites More sharing options...
ArtVandelay Posted September 5, 2017 Report Share Posted September 5, 2017 I 8 minutes ago, StevenL757 said: They were probably firing to the point where numerical values were indicating, but not enough to show on your bar graphs (if you have an EDM7xx, 8xx, or 9xx, or other graphical EM). Agreed, download and review the data in detail sounds like the next step to see what you can make of it. Quote Link to comment Share on other sites More sharing options...
Mark89114 Posted September 5, 2017 Author Report Share Posted September 5, 2017 I will get it downloaded in the near future..... Just had the mags 500 IRAN and new wiring harness, timing is good. This was done about 15 hours ago. I follow the checklist for appropriate start. Run LOP and 65% or less power, I like to go high eastbound. Oil is changed every 50 hours, most of my flying is long distance legs, 2-3-4 hours at a time. This did happen once about a year ago and I just assumed it was early morning sickness as the plane had been sitting for 2-3 weeks. TT on engine is about 800 hours. The engine runs like a top, I get very low RPM drops on magnetos, usually 60 RPM or less. "Oil on the right hand side plugs only" - per Steven757, doesn't sound logical, why just that side? again the engine was rough. Will get the JPI data out in soon. Thanks, Mark Quote Link to comment Share on other sites More sharing options...
StevenL757 Posted September 5, 2017 Report Share Posted September 5, 2017 2 hours ago, Mark89114 said: "Oil on the right hand side plugs only" - per Steven757, doesn't sound logical, why just that side? again the engine was rough. Will get the JPI data out in soon. Thanks, Mark Hard to say for certain...just a possibility based on your problem statements. It's possible cylinders 1, 3, and 5 may not have been the only ones impacted, but the fact that the condition cleared during run-up indicates that something may have gone screwy during the start-up process, which is known to happen to many engines, not just the IO550(x). I checked in with my IA earlier and ran this by him. Although he agreed with my content earlier, he mentioned your valves could also be culprits. He tended to rule out (and I agree) fuel flow divider (spider), injectors, and mags, as they would all individually and collectively display different and more consistent behavior than you described. What's significant is that after run-up, you were getting fuel, air, and spark, so things at that point were behaving as they should. Certainly look at the JPI data, but understand it may not definitively point to a single culprit. May not be related, but you may want to consider installing iridium finewire plugs...specifically Tempest URHB-32S plugs. Most people have a hard time justifying $900 - $1k worth of plugs in an engine, but I swear by them, and they are an excellent match for your new harness and Bendix/CMI mags. Those three components constitute the best ignition system possible for the IO550 platform, so certainly consider ordering a box of twelve. Lastly, I would suggest moving towards a 25-30-hour/3 months max oil change interval instead of 50 hours. Our operating habits and legs flown are similar, and I personally have no reservations about spending a little bit more on more frequent oil changes so the oil never loses its lubricating properties. Given longer legs, you can probably get along fine with 30 hours/3 months between changes, but for shorter legs, stick with 25 hours/3 months. Not sure if you do your own changes, but I generally tend to buy filters and oil in bulk (several years' worth at a time) so I always have stock on-hand. Based on my IA's feedback (a former Mooney 7000+ hour test pilot, and former chief of maint. there), as long as the condition clears during run-up, go ahead and fly. Let us know what you find out from the JPI data, and if you decide to have your A&P/IA have a look. I'm sure you're already in good hands, but if you're in the area, you're always welcome to show up at my airport and I'll go fly with you to lend some eyes and ears. Steve Quote Link to comment Share on other sites More sharing options...
carusoam Posted September 6, 2017 Report Share Posted September 6, 2017 ++ for JPI data to see if valves are misbehaving. Any sawtooth pattern of EGTs is an indication of sticky valves that are related to morning sickness. I haven't seen much funky IO550 data to point to. Best regards, -a- Quote Link to comment Share on other sites More sharing options...
N231BN Posted September 9, 2017 Report Share Posted September 9, 2017 Do you have a top or bottom induction 550? If it's the bottom log ram induction a sticky intake valve could shut a whole side down. Much less likely with the curved top induction. Quote Link to comment Share on other sites More sharing options...
carusoam Posted September 10, 2017 Report Share Posted September 10, 2017 Rs get the curvy balanced intake tubes... But, interesting point, about one Stuck intake valve on the side interrupting the normal airflow of the other cylinders that share the pipes... Best regards, -a- Quote Link to comment Share on other sites More sharing options...
Mark89114 Posted September 10, 2017 Author Report Share Posted September 10, 2017 Sorry for the delay....I am lazy..... Mechanic came and looked at it......didn't do any real investigating. He did call his fuel injection overhaul guys and described the problem. The FI guy did ask if their were any "humps" in the injector lines, i.e. they went up over and then back down, all three lines go over the curved intake tubes. The theory is the pressure is just a little bit low and not getting full fuel to the injectors. I led everybody wrong on my original post, the cylinders are firing as evidenced by the EGT's, just sure didn't seem like it as nothing was showing graphically and the vibration. Posting the data here, if somebody is more of an expert on getting this massaged into a more useful form, please let me know. Going to take the plane down to his shop before I fly out commercially (yuck) and have the injectors all cleaned and the fuel pressure checked and set. low egt 5 3 1.csv low egt 5 3 1.pdf Quote Link to comment Share on other sites More sharing options...
carusoam Posted September 11, 2017 Report Share Posted September 11, 2017 Mark, you really captured the situation with the data in the chart... The odd number cylinders took a minute to come up on the EGTs... 1&5 were slower than 3. Do you know if the electric fuel pump was on during this start-up? Hi or Low, or no? It would be interesting if this behavior shows up during the Run-up... Looking back at the JPI data files... how long ago did this begin happening? Any recent Gami spreads? Overall, it kind of looks like a hot start where one side of the engine was cooler than the other. Something caused the fuel lines on one side to be or get emptied. The concern for bends in the fuel lines are probably related to how well an air or vapor bubble can be entrained in the tube, interfering with flow in each line... hence the request about the fuel pump being on, hi or low? Do you have any FF numbers to go with that? After start, MP sets rpm to 1000...to warm up. Full rich has the FF near a number larger than 2gph... after leaning for taxi, the FF is right on or about 2.0 gph.(?) (Working with fuzzy memories tonight). You might want to share a screenshot of the graph that covers the data. A picture is worth a thousand data points. Best regards, -a- Quote Link to comment Share on other sites More sharing options...
Mark89114 Posted September 11, 2017 Author Report Share Posted September 11, 2017 Fuel pump is OFF during engine start per the POH. On cold starts I usually get ignition within 1/2 turn or so, which I think is very quick. This has only happened one other time before, months before, and I just wrote it off to the airplane sitting or whatever magical gremlin decides to show up that day. But twice made me pay attention, as it is was the 5-3-1 cylinders which I think is super weird. I really like the theory that is is the bends in the fuel lines are creating vapor lock, poor flow, based on low fuel pressure, etc. Even this day after cylinders started firing normal, the runup was normal, mag drop is about 60-70 and smooth on either mag. I really don't buy the stuck intake valve theory causing the others to balk, as they are firing. Plan is to take plane to mechanic, going to clean and check all injectors and check injector fuel pressure. There is some theory about a diaphragm inside the spider being cantakerous, but I don't know what the inside of that looks like. Based on the fuel injection expert asking one question if there were "humps" fits intuitively to defining the problem. Finding solution is another matter.... Quote Link to comment Share on other sites More sharing options...
carusoam Posted September 11, 2017 Report Share Posted September 11, 2017 If it happens again, turn on the low fuel pump after start..? (Sort of like opening the 'choke') This comes from my experience for cooler days. The engine would starve from not enough fuel vaporizing. I never analyzed what cylinders were not playing along when this occurred. Last thought for the fuel injector specialist... there might be a seal failure that is allowing air in the lines going to one side? The fuel that resides in the lines is draining out on 1,3,&5, see if it is showing up in the injection system drain...? It does seem pretty unusual. Good luck finding the resolution. Do you have a contact at Continental Motors? Best regards, -a- Quote Link to comment Share on other sites More sharing options...
StevenL757 Posted September 20, 2017 Report Share Posted September 20, 2017 Mark - any more progress on this? If not, I have a contact that will be helpful. Steve Quote Link to comment Share on other sites More sharing options...
Mark89114 Posted September 20, 2017 Author Report Share Posted September 20, 2017 Mechanic looking at this week. Will advise. Quote Link to comment Share on other sites More sharing options...
Mark89114 Posted September 25, 2017 Author Report Share Posted September 25, 2017 Sorry it takes so long to respond. I read responses all day long on the phone but I hate responding on them as the $%&( auto correct on grammar and spelling drives me nuts.... Mechanic pulled the injectors, all looked clean and in good shape. Soaked them in solvent and cleaned up. Checked fuel pressure and it was within tolerances on the high side so no issue there. The engine runs fantastically all of the time, CHT's are cool, mag drops are well within tolerance, no weird fuel draining, cold starts are 1/2 prop, hot starts are the usual Fuel Injected issues (but pretty good), etc. I have no problem flying the plane, I just think as someone mentioned sometimes they are weird starts. Thanks for the input everybody. Quote Link to comment Share on other sites More sharing options...
Brian_tii Posted September 29, 2017 Report Share Posted September 29, 2017 Sounds like some good ideas already mentioned. Here are a few long shots / thoughts that I had: 1) Was it parked on a hill sideways that could maybe cause oil to want to pool on that side? I know it's unlikely... but being a horizontally opposed engine it seems you could have oil stuck on the back side of the piston, if sitting on a slant it may over time migrate past the rings and oil foul the cylinders. 2) Was the engine fully warmed up before shutdown last time it ran before this start? On cars I've seen some are very prone to sticking valves if they are shutdown before warm up. (Like moving quickly in / out of the garage). I think condensation forms and a light coat of rust develops on the exhaust valve causing it to be a little sticky on the next startup. (My theory) If it's either of the above, it's nothing to worry about in my opinion. Quote Link to comment Share on other sites More sharing options...
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