takair Posted March 22, 2018 Report Share Posted March 22, 2018 50 minutes ago, teejayevans said: The engine fuel pump part numbers is listed in the TCDS, if it’s different I would expect a call to the FAA telling them Lycoming change part numbers would result in the Lycoming getting a unpleasant call from the FAA. There are more details on part numbers in this thread. I tried to document my findings. Lycoming uses a SL L255A to cover this. Problem is only on Mooney aircraft, which have lower max limit. Quote Link to comment Share on other sites More sharing options...
Yetti Posted March 22, 2018 Report Share Posted March 22, 2018 I would be voting for leaking induction tube or mis behaving servo for extra fuel on shutdown. Getting something sucked into the servo may cause it to misbehave. Another thing to check is see if the fuel is getting to the oil in the crankcase. Rising oil levels or wrong smells. Quote Link to comment Share on other sites More sharing options...
jaylw314 Posted March 23, 2018 Report Share Posted March 23, 2018 @Luke, any updates? Quote Link to comment Share on other sites More sharing options...
Piloto Posted March 25, 2018 Report Share Posted March 25, 2018 (edited) Luke, on the next cold start 1. Set to max throttle. 2. Mixture full rich. 3. Prime engine with electric fuel pump. If pressure is just barely above red line the engine may not start. 4. After 3 seconds close mixture and turn pump off. 5. Set throttle to halfway. 6. Crank engine. At first sign of engine combustion push mixture to full rich. 7. After start set throttle to idle. I had a similar problem at KAGC in winter but not a KFXE. Replaced the electric fuel pump and now I was able to start at 8F on the first crank turn. If the electric pump is weak you may be able to start the engine by having the electric pump on while cranking the engine and opening the mixture slowly. José Edited March 25, 2018 by Piloto Quote Link to comment Share on other sites More sharing options...
Luke Posted March 30, 2018 Author Report Share Posted March 30, 2018 I'm still waiting for my local shop to have time, so I popped off the cowling to have a look today. I think we have a winner! What you're looking at here is the business end of the mixture control cable, pulled into cutoff. (I'm pretty sure that) there's supposed to be a screw and spacer that prevents the arm from traveling into the position that you see here. If this particular position allows even a bit of fuel flow then the engine would flood easily. I'm even fairly sure that said screw is supposed to have safety wire on it, and since I'm only about 100 hours into a Lycoming factory overhaul... Hmm... I'll post back once I get confirmation from my A&P. 1 Quote Link to comment Share on other sites More sharing options...
Guest Posted March 30, 2018 Report Share Posted March 30, 2018 1 hour ago, Luke said: I'm still waiting for my local shop to have time, so I popped off the cowling to have a look today. I think we have a winner! What you're looking at here is the business end of the mixture control cable, pulled into cutoff. (I'm pretty sure that) there's supposed to be a screw and spacer that prevents the arm from traveling into the position that you see here. If this particular position allows even a bit of fuel flow then the engine would flood easily. I'm even fairly sure that said screw is supposed to have safety wire on it, and since I'm only about 100 hours into a Lycoming factory overhaul... Hmm... I'll post back once I get confirmation from my A&P. You are correct. There would normally be a screw with a nylon spacer and a screw with safety wire at the ICO end of the arm. Clarence Quote Link to comment Share on other sites More sharing options...
carusoam Posted March 31, 2018 Report Share Posted March 31, 2018 Nice clean pic, Luke! Since you have the mixture pulled to idle cut off... I see the two tabs/stops marked R and ICO.... My guess is Rich and Idle Cut Off are not reaching the (or a) stop... As Clarence pointed out, there is something missing there... It is good to have M20Doc here! Best regards, -a- Quote Link to comment Share on other sites More sharing options...
Luke Posted April 2, 2018 Author Report Share Posted April 2, 2018 To follow up on the second piece of this thread, I just spoke to Lycoming about the fuel pressure on the IO-360-A3B6 being higher than spec'ed for the M20J airframe. I got a lot of "mumble mumble call Avstar" but after a while it seemed like the guy I spoke to found information, then quickly rattled off a part number of a replacement fuel pump (LW15473) that's rated for 30 psi. He mentioned that others have gotten the swap covered under warranty, which I may try at my next annual. Let me know if others have success with the same! 1 Quote Link to comment Share on other sites More sharing options...
pinerunner Posted April 2, 2018 Report Share Posted April 2, 2018 (edited) I my case I once had puddles forming after dripping from the tube attached to the auxiliary fuel pump. My mechanic sent it away for a rebuild and the problem was cured for under a thousand dollars. You should be able to sort out which tube it's coming from and trace it back to the component that's going bad. You need a mechanic in the end but you can help track it down and save time. Rubber seals deteriorate with age. I had a few cases where I forgot to turn off the boost pump and that may have made the problem worse by running it 10x more than advisable. It started with a little dripping and then got worse and worse. Checklists, checklists, checklists. Edited April 2, 2018 by pinerunner Quote Link to comment Share on other sites More sharing options...
Luke Posted April 2, 2018 Author Report Share Posted April 2, 2018 13 minutes ago, pinerunner said: sort out which tube it's coming from Ah I forgot to post the answer. The tube dripping huge amounts of fuel is the one attached to the sniffle valve. The theory that I think fits is that the missing stop allows fuel to flow when the mixture is pulled to cutoff during a normal start, flooding the engine. So the sniffle valve is hopefully fine and doing its job here. 1 Quote Link to comment Share on other sites More sharing options...
Luke Posted April 4, 2018 Author Report Share Posted April 4, 2018 Just to wrap up: my A&P replaced the missing stop / screw yesterday and we're back flying again. A big thanks for great service from both Avstar and C&W Aero at KCDW on this. My A&P mentioned that he's done a couple of fuel pump warranty replacements on overhauled A3B6 engines in Mooneys... so that's probably in my future too! Thanks all for the input and advice. Fly safe. 1 Quote Link to comment Share on other sites More sharing options...
jaylw314 Posted April 4, 2018 Report Share Posted April 4, 2018 Thanks for the follow up, glad it was a simple repair. Good catch! Quote Link to comment Share on other sites More sharing options...
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