carusoam Posted May 24, 2016 Report Posted May 24, 2016 One PP's opinion of what he sees... If the overall FF hasn't changed, and one injector is flowing more... It is sure that the remaining three are flowing less... It sounds to me, like... One has gone too rich and at least one other seemed to have gone too lean to fire. Logic enough that I would stop flying the plane until a flow test can be performed on the FIs. The test has a few names like baby food jar test. Essentially, time the flow into four separate jars. Determine how much fuel landed in each jar. They should be identical. This type of work is done by mechanics. Sounds like you want to be there when he does it. Downloading the data off the GEM has become a priority. You have described something not working right. People are telling you get it fixed before flying it. I'm chipping in the fact that mechanical things aren't known to fix themselves. prepare yourself with drawings of the fuel injectors that you have and know where the screens are upstream. Another thing to be prepared with is Hopp's cleaning solution. Often used for cleaning fuel injection systems and gun barrels. PP typed information. I am not a mechanic. But, my level of concern is starting to grow... Let me know if I missed something. Best regards, -a- Quote
Brian Scranton Posted June 1, 2016 Author Report Posted June 1, 2016 Update! So, I switched (#3 and #1) back to the original configuration and all seemed good. Remember, #3 EGT sky rocketed and then quit, so the #3 injector is back to the #1 cylinder (it's original place). I flew for 2 hours, EGTs all good. Then, a few days later, flew again and #1 had 5 bars over all the others. Only at full power, though. So didn't see it on run-up and the mag check was fine! Pulled power back from 25'' to 20'' and EGTs were all level. Hmmm... So, I pulled that injector (this one has the stainless steel insert, unlike the other 3 injectors I have), pulled the insert and saw some junk at the bottom. Gave her a good cleaning in some acetone and put her back in. Back to normal--at least for now--flew another 1.5 hours and the EGTs were fine. I'll fly again today and see... Quote
carusoam Posted June 1, 2016 Report Posted June 1, 2016 Any hint to what was in the injector? There is supposed to be a screen upstream that usually keeps things from getting that far. Some fuel lines have been known to let their rubber liner leave some bits down stream... Best regards, -a- 1 Quote
Guest Posted June 1, 2016 Report Posted June 1, 2016 2 hours ago, Brian Scranton said: Update! So, I switched (#3 and #1) back to the original configuration and all seemed good. Remember, #3 EGT sky rocketed and then quit, so the #3 injector is back to the #1 cylinder (it's original place). I flew for 2 hours, EGTs all good. Then, a few days later, flew again and #1 had 5 bars over all the others. Only at full power, though. So didn't see it on run-up and the mag check was fine! Pulled power back from 25'' to 20'' and EGTs were all level. Hmmm... So, I pulled that injector (this one has the stainless steel insert, unlike the other 3 injectors I have), pulled the insert and saw some junk at the bottom. Gave her a good cleaning in some acetone and put her back in. Back to normal--at least for now--flew another 1.5 hours and the EGTs were fine. I'll fly again today and see... The only unfiltered part of the system is the rubber hose from the servo outlet fitting to the flow divider inlet fitting. I would consider replacing it. Clarence Quote
mike_elliott Posted June 1, 2016 Report Posted June 1, 2016 38 minutes ago, M20Doc said: The only unfiltered part of the system is the rubber hose from the servo outlet fitting to the flow divider inlet fitting. I would consider replacing it. Clarence Nothing should get past the finger strainer on the Servo, but I have found small chunks of tank sealant once in an injector. One might, in addition to Clarence's great advice, consider checking the finger strainer and the gascolater screen. Make sure you know the proper torque for the gascolater and have the proper O ring for the finger strainer. 1 Quote
Brian Scranton Posted June 2, 2016 Author Report Posted June 2, 2016 When I first swapped all the injectors, I showed them to my A&P and he said, "great, they look good--put em back in" and so I did. We (I) never cleaned them. Dirty hands, engine junk, who knows...but when I finally pulled the troubled injector and removed the stainless insert I found what looked like a black speck hanging out in there. Showed my A&P and he said, "yup--that would do it, looks like you have some trash in there." So, I dropped the injector/insert into some acetone and it dissolved the carbon (or whatever it was)... Flew again last night and all is fine. So, unless something else goes wrong, the moral of the story is to clean your injectors when you remove them. Which isn't really a moral so much as common sense. Which I seem to lack. Where the speck came from? Well, we can only speck-ulate. Quote
jetdriven Posted June 2, 2016 Report Posted June 2, 2016 Harbor freight sells a nice ultra sonic cleaner that cleans the injectors very well with Acetone or Hoppes #9 gun cleaner. 2 Quote
mike_elliott Posted June 2, 2016 Report Posted June 2, 2016 3 hours ago, jetdriven said: Harbor freight sells a nice ultra sonic cleaner that cleans the injectors very well with Acetone or Hoppes #9 gun cleaner. AND you can bring it home to let the wifey clean her jewelry with. A win win on the wife/aluminum mistress score card. 1 Quote
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