manu damaschin Posted September 8, 2013 Report Posted September 8, 2013 I have very short engine power fluctuations on my TSIO 360 LB...sometimes in cruise flight other times in climb. The mechanic's opinion is that there isn't an electronic problem but a fuel system one. The fluctuations are very short in time but they repeat for 3,4 times and then everything is ok... Any ideas...? Quote
N201MKTurbo Posted September 8, 2013 Report Posted September 8, 2013 Sucking air into your fuel lines, probably at the selector. Quote
manu damaschin Posted September 8, 2013 Author Report Posted September 8, 2013 Sucking air into your fuel lines, probably at the selector. Thanks for the tip...! I will check tomorow... Quote
marks Posted September 11, 2013 Report Posted September 11, 2013 I have the same problem. I fly along at 11.9 gph and then I look back and I'm at 13 gph. My mechanic says the fuel servo is to blame. My first thought was that is was simply the mixture control, but no it isn't. Overhauling the fuel servo can be quite expensive. Usually the fuel fluctuations are only a few tenths of a gallon at a time and can go either way. Sometimes things stay the same for 15 minutes, but when flying LOP I am constantly watching the fuel meter. Quote
manu damaschin Posted September 11, 2013 Author Report Posted September 11, 2013 I have the same problem. I fly along at 11.9 gph and then I look back and I'm at 13 gph. My mechanic says the fuel servo is to blame. My first thought was that is was simply the mixture control, but no it isn't. Overhauling the fuel servo can be quite expensive. Usually the fuel fluctuations are only a few tenths of a gallon at a time and can go either way. Sometimes things stay the same for 15 minutes, but when flying LOP I am constantly watching the fuel meter. Thanks Mark...but do you also have short time power fluctuations? I mean so short that I don't have time to watch how much the RPM drops... Quote
marks Posted September 13, 2013 Report Posted September 13, 2013 manu, Maybe we don't have the same problem. Unless the mixture turns so lean that the RPMs are affected I don't have any symptoms. For me the problem is that the fuel becomes far more rich, the exhaust temps fall, but the RPMs stay the same. Sometimes the opposite happens, but once flying along LOP the engine missed and sounded like it would quit. Pushing the mixture forward fixed the problem instantly. - Many things could cause a momentary loss of power. Perhaps you've got a hanging exhaust valve, or maybe a dying spark plug. If there's fuel and spark the engine should keep running. I think this site is great for looking for the "quick fix" but sometimes the problem can be harder to find. Please keep us posted. Most problems don't get better on their own. Quote
manu damaschin Posted September 13, 2013 Author Report Posted September 13, 2013 manu, Maybe we don't have the same problem. Unless the mixture turns so lean that the RPMs are affected I don't have any symptoms. For me the problem is that the fuel becomes far more rich, the exhaust temps fall, but the RPMs stay the same. Sometimes the opposite happens, but once flying along LOP the engine missed and sounded like it would quit. Pushing the mixture forward fixed the problem instantly. - Many things could cause a momentary loss of power. Perhaps you've got a hanging exhaust valve, or maybe a dying spark plug. If there's fuel and spark the engine should keep running. I think this site is great for looking for the "quick fix" but sometimes the problem can be harder to find. Please keep us posted. Most problems don't get better on their own. Mark, for sure I have a different problem, but thanks for input anyway...! I will keep you all posted... Quote
jetdriven Posted September 13, 2013 Report Posted September 13, 2013 Sucking air into your fuel lines, probably at the selector. Mine is a J, but I did the same thing, rebuilt the fuel selector. Then it came back, but not as bad. It was either a faulty mechanical fuel pump, or vapor lock from a hot fuel hose that goes from the firewall to the pump. I put an extra piece of firesleeve over the hose, and replaced the pump. Rock steady fuel pressure now. Quote
BigTex Posted September 13, 2013 Report Posted September 13, 2013 I had something similar when I first purchased my plane. Mine seemed like a hesitation and seemed to occur more often when I pull power. In some cases it seemed like it got a swig of water. I had my mags overhauled and haven't seen it since. Quote
manu damaschin Posted September 14, 2013 Author Report Posted September 14, 2013 Problem solved: the fuel system was sucking air through a fuel line (one of the priming fuel lines)...the connection screw was loose. Quote
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.