DonMuncy Posted September 8, 2017 Report Posted September 8, 2017 I frequently see where people are cleaning their fuel injectors. I have had clogged injectors (with a bit of debris) that had to be cleared/cleaned. But I don't think I have ever seen one that was obstructed with any kind of gunk that would require something to dissolve the stuff. It would seem that it would take a strange kind of material that would stick to the injector while being constantly washed by avgas. Are injector cleaners a "scam". What do you think?
Hank Posted September 8, 2017 Report Posted September 8, 2017 I've heard and read good things about Hoppe's #9, which also has other uses in the house. Always have a bottle around somewhere . . . 2
gsengle Posted September 8, 2017 Report Posted September 8, 2017 Good question but I've certainly had a clogged injector before.Sent from my iPhone using Tapatalk
BDPetersen Posted September 8, 2017 Report Posted September 8, 2017 Once removed, ultrasonic cleaners seem to be effective on injectors. 2
carusoam Posted September 8, 2017 Report Posted September 8, 2017 A few ideas... 1) I have used it in the automotive world. The Chevron branded stuff added to fuel tank. Oddly enough, it gives a noticeable change. Done every 50kmi. Engine: 300hp IV350 (water cooled) 2) I have cleaned the intake tubes of the O360 where fuel is vaporized on its way to the intake valves. With all the evaporation going on, the blue dye wants to deposit thickly on any surface. 3) As for our continuous fuel injectors... there is a vent hole allowing air entry, and a drain. It is possible that these devices can allow some blue deposits to form in the area of the fuel injector. 4) downstream of the injector where the fuel is spraying and evaporating may get some blue goo formation. 5) search for Hopp's gun cleaner. The preferred solvent for cleaning fuel injectors around here... PP ideas only, not a mechanic... Best regards, -a-
jetdriven Posted September 8, 2017 Report Posted September 8, 2017 Hoppes #9 in the harbor freight ultrasonic parts cleaner works great. 3
RobertGary1 Posted September 8, 2017 Report Posted September 8, 2017 IVe certainly had clogged injectors. 90% of the time it's in the insert so no need to remove the injector. Just remove the insert and soak or something's blow it. I've seen visible debris before. I've only used the MEK that Lycoming calls for. -Robert
MB65E Posted September 8, 2017 Report Posted September 8, 2017 I don't think it's a scam, however you'll know when one is clogged. I no longer clean injectors just to clean injectors. It seems that about 60-70% of the time , after cleaning, a sliver of something gets knocked loose and ends up clogging the injector again. Having one clogged will get your full undivided attention!! I wouldn't wholesale this theory, but just don't clean them to clean them. -Matt 1
StevenL757 Posted September 8, 2017 Report Posted September 8, 2017 11 hours ago, Hank said: I've heard and read good things about Hoppe's #9, which also has other uses in the house. Always have a bottle around somewhere . . . Yep...exactly what we do every annual. All six get soaked in Hoppes for a couple hours, then rinsed with acetone, blown clear, inspected, and put into a ziplock for re installation with fresh o-rings. Never had a glitch.
DonMuncy Posted September 8, 2017 Author Report Posted September 8, 2017 I understand about the various ways and solvents for cleaning injectors, and I certainly understand about slivers, etc. that block injectors and have to be removed. But my point was, has anyone seen an injector that had a build-up of some material that needed to be dissolved before function could be restored.
Andy95W Posted September 8, 2017 Report Posted September 8, 2017 I've seen what must amount to a slow but steady buildup of gas "varnish" that prevents a GAMI injector equipped engine not be able to run LOP until the injectors were cleaned. 1
DonMuncy Posted September 8, 2017 Author Report Posted September 8, 2017 1 minute ago, Andy95W said: I've seen what must amount to a slow but steady buildup of gas "varnish" that prevents a GAMI injector equipped engine not be able to run LOP until the injectors were cleaned. Very interesting. I assume you are saying that over a period of time, the engine gets progressively rougher at the same fuel flow, or requires less leaning to run smooth, and then after using solvent on the injectors, the prior (smooth running at x gph) condition was restored. At the risk of sounding like I am questioning your veracity (which I am not), can anyone think of any other explanation.
N201MKTurbo Posted September 8, 2017 Report Posted September 8, 2017 I see deposits on the nozzle. I've never seen any on the fuel orifice. That would take a microscope to see. If the fuel orifices did get a buildup, it would most likely make all cylinders a bit leaner, but would not drastically change the mixture distribution between cylinders.
Andy95W Posted September 8, 2017 Report Posted September 8, 2017 FWIW, it was a customer's 1999 Beechcraft Bonanza (A36) with a Continental IO-550. Came from the factory with GAMI injectors installed. He would consistently complain of rough running when LOP as the airplane got closer and closer to its Annual Inspection. We changed his oil every 30-50 hours, but wouldn't touch the injectors until the Annual. We started cleaning his injectors every oil change and he stopped complaining. BTW, I also did most of his Instrument training in that Bonanza and he was a very good pilot and not given to overreaction. That's the closest thing I've got to "evidence". Probably not enough to hang your hat on, but enough to make you scratch your head.
RobertGary1 Posted September 8, 2017 Report Posted September 8, 2017 2 hours ago, DonMuncy said: Very interesting. I assume you are saying that over a period of time, the engine gets progressively rougher at the same fuel flow, or requires less leaning to run smooth, and then after using solvent on the injectors, the prior (smooth running at x gph) condition was restored. At the risk of sounding like I am questioning your veracity (which I am not), can anyone think of any other explanation. For me its the EGT spreads. When they start to drift from each other is when I pull the inserts (never bother with pulling the entire injector). -Robert
kortopates Posted September 8, 2017 Report Posted September 8, 2017 Most or at least many injectors get partial blockages from installing them - piece of o-ring gets nicked or a little debris gets into the line when it's put back in place. This is an operation you want to do with the utmost cleanliness or you can do worse than you started. That said, most injectors do need cleaning eventually, but NA engines shouldn't need it every annual. But turbo injectors are a different story being pressurized with UDP and will require significantly more maintenance just like pressurized mags. As for maintaining them, this is best done by using a data driven approach - not on an arbitrary schedule but when warranted. The Savvy pilot knows their gami spreads and when they see the rankings from to lean to rich change then spots the injector(s) getting leaner; before the spread size changes significantly. I hope the difference is clear. Sent from my iPhone using Tapatalk
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