Engine quitting... - Zenith Aircraft Builders and Flyers2024-03-28T20:11:49Zhttps://zenith.aero/forum/topics/engine-quitting?commentId=2606393%3AComment%3A725549&feed=yes&xn_auth=noI'd bet you had a little air…tag:zenith.aero,2020-07-30:2606393:Comment:7305642020-07-30T19:58:01.522ZJohn Bellhttps://zenith.aero/profile/JohnBell
<p>I'd bet you had a little air in leakage on the standby pump, through a crush washer. Where I worked, this was not uncommon after pump rebuilds with new gaskets/washers. Not enough air to affect operation but enough to get a bubble in the non running pump circuit.</p>
<p>Good to hear it worked out.</p>
<p>John.</p>
<p></p>
<p>I'd bet you had a little air in leakage on the standby pump, through a crush washer. Where I worked, this was not uncommon after pump rebuilds with new gaskets/washers. Not enough air to affect operation but enough to get a bubble in the non running pump circuit.</p>
<p>Good to hear it worked out.</p>
<p>John.</p>
<p></p> I finally received my parts t…tag:zenith.aero,2020-07-30:2606393:Comment:7305622020-07-30T18:50:44.558ZMark Pensenstadlerhttps://zenith.aero/profile/MarkPensenstadler
<p>I finally received my parts to do the SB, but I'm no longer having this issue. Some may remember that I had an issue with a few of the banjo fittings on the final fuel filter and the fuel pumps leaking. I removed the pumps, annealed my copper washers, and rebuilt it and I no longer seem to have the issue with the engine quitting when changing pumps. Not sure if rebuilding had any affect, but either way I haven't had the issue since.</p>
<p></p>
<p>I'll prob still do the service bulletin…</p>
<p>I finally received my parts to do the SB, but I'm no longer having this issue. Some may remember that I had an issue with a few of the banjo fittings on the final fuel filter and the fuel pumps leaking. I removed the pumps, annealed my copper washers, and rebuilt it and I no longer seem to have the issue with the engine quitting when changing pumps. Not sure if rebuilding had any affect, but either way I haven't had the issue since.</p>
<p></p>
<p>I'll prob still do the service bulletin though since I have the parts even though I don' think the new part that UL Power wants the owners to swap has any affect on the issue of the engine quitting. The problem is losing fuel pressure during the pump switch.</p> I have not done the 2019-2 SB…tag:zenith.aero,2020-07-30:2606393:Comment:7305592020-07-30T18:45:49.730ZScott Millerhttps://zenith.aero/profile/ScottMiller
<p>I have not done the 2019-2 SB and I don't think it is necessary for me as I have a header tank and can only think of a couple of ways how it would "unport" the fuel supply which are avoidable. I have switched pumps in flight with no observable issues. I recently had the Circuit Breaker on my main pump trip during climb-out and I immediately switched to the aux pump and the engine restarted without me turning the key.</p>
<p>I have not done the 2019-2 SB and I don't think it is necessary for me as I have a header tank and can only think of a couple of ways how it would "unport" the fuel supply which are avoidable. I have switched pumps in flight with no observable issues. I recently had the Circuit Breaker on my main pump trip during climb-out and I immediately switched to the aux pump and the engine restarted without me turning the key.</p> The ability to run both pumps…tag:zenith.aero,2020-07-19:2606393:Comment:7289692020-07-19T15:39:44.355ZJohn Bellhttps://zenith.aero/profile/JohnBell
<p>The ability to run both pumps on take off and landing was the single biggest reason I switched the pumps separately, not that that may have to be standard practice but I just like having the capability if so desired.</p>
<p>Agreed on wether it’s an actual problem either way. Just a good thing to be aware of and proceduralize.</p>
<p>John</p>
<p>The ability to run both pumps on take off and landing was the single biggest reason I switched the pumps separately, not that that may have to be standard practice but I just like having the capability if so desired.</p>
<p>Agreed on wether it’s an actual problem either way. Just a good thing to be aware of and proceduralize.</p>
<p>John</p> John,
The question is, is th…tag:zenith.aero,2020-07-19:2606393:Comment:7289612020-07-19T12:25:53.598ZRalph Powellhttps://zenith.aero/profile/RalphPowell
<p>John,</p>
<p></p>
<p>The question is, is there a problem? Dual fuel pumps are there in the hopefully rare case where one fails. How often does that happen? If the pumps have a known life scheduled replacement might be an excellent solution to the weight penalty of a second pump. Next, rather than a complicated switch system, adding switching and testing pumps as part of preflight would appear to reduce some concerns of a lag on switching over during climb out. The other common way of…</p>
<p>John,</p>
<p></p>
<p>The question is, is there a problem? Dual fuel pumps are there in the hopefully rare case where one fails. How often does that happen? If the pumps have a known life scheduled replacement might be an excellent solution to the weight penalty of a second pump. Next, rather than a complicated switch system, adding switching and testing pumps as part of preflight would appear to reduce some concerns of a lag on switching over during climb out. The other common way of addressing the issue is to run both pumps during takeoff or landing. I lost a fuel pump in a 172xp during climb out and having a second pump to switch to did not save me from a forced landing. When flying really low and the engine quits you do not have time to trouble shoot, you are to busy flying the plane. The conclusion is that there may not be a clean simple solution of this possible issue.<br/><br/></p>
<p>Ralph</p> Hey guys. I’m watching this d…tag:zenith.aero,2020-07-18:2606393:Comment:7288322020-07-18T11:04:13.770ZJohn Bellhttps://zenith.aero/profile/JohnBell
<p>Hey guys. I’m watching this discussion with interest as I have the same engine/pumps as you two. Sounds like you both have a one or the other pump circuit. Wondering if installing a separate switch for each pump, allowing the standby pump to be selected on before shutting down the running pump, would fix the problem? Wouldn’t help in a real time running pump failure but at least be able to have a smoother transition for the planned or partial failure scenarios. I have installed 2 switches…</p>
<p>Hey guys. I’m watching this discussion with interest as I have the same engine/pumps as you two. Sounds like you both have a one or the other pump circuit. Wondering if installing a separate switch for each pump, allowing the standby pump to be selected on before shutting down the running pump, would fix the problem? Wouldn’t help in a real time running pump failure but at least be able to have a smoother transition for the planned or partial failure scenarios. I have installed 2 switches but am not quite at the engine test run point yet.</p>
<p>John</p> All,
Good news! Went up for…tag:zenith.aero,2020-07-18:2606393:Comment:7289052020-07-18T03:17:28.878ZRalph Powellhttps://zenith.aero/profile/RalphPowell
<p>All,</p>
<p></p>
<p>Good news! Went up for a test flight tonight and switched fuel pumps. At first there was silence, but then if I waited long enough...the second pump would come up to pressure and the engine would restart. The wait was 5-15 seconds? Seemed longer. When switching while taxiing the lag was long enough that the engine would die and require use of the ignition starter to fire up. <br></br><br></br></p>
<p>The winds aloft were 30-40 mph tonight but smooth. Good flying weather, flying…</p>
<p>All,</p>
<p></p>
<p>Good news! Went up for a test flight tonight and switched fuel pumps. At first there was silence, but then if I waited long enough...the second pump would come up to pressure and the engine would restart. The wait was 5-15 seconds? Seemed longer. When switching while taxiing the lag was long enough that the engine would die and require use of the ignition starter to fire up. <br/><br/></p>
<p>The winds aloft were 30-40 mph tonight but smooth. Good flying weather, flying around a point would have been tough.</p>
<p></p>
<p>Ralph</p>
<p></p> All,
While testing for leaks…tag:zenith.aero,2020-07-17:2606393:Comment:7289042020-07-17T23:34:55.855ZRalph Powellhttps://zenith.aero/profile/RalphPowell
<p>All,</p>
<p></p>
<p>While testing for leaks after replacing the filters I noticed that the two pumps came up to pressure in about the same amount of time, however they sound different from each other while operating. Do the pumps sound the same on yours? When and if the winds here drop down I will flight test the filter change, not holding out much hope that is was the filters causing the problem.Thinking about ordering a new pump come Monday.</p>
<p></p>
<p>Ralph</p>
<p>All,</p>
<p></p>
<p>While testing for leaks after replacing the filters I noticed that the two pumps came up to pressure in about the same amount of time, however they sound different from each other while operating. Do the pumps sound the same on yours? When and if the winds here drop down I will flight test the filter change, not holding out much hope that is was the filters causing the problem.Thinking about ordering a new pump come Monday.</p>
<p></p>
<p>Ralph</p> Mark,
Noticed a similar issu…tag:zenith.aero,2020-07-17:2606393:Comment:7288982020-07-17T21:06:27.566ZRalph Powellhttps://zenith.aero/profile/RalphPowell
<p>Mark,</p>
<p></p>
<p>Noticed a similar issue with my engine. I switched in cross country flight today and had a brief, very brief, moment of silence before switching back to pump 1. Tested again while circling over a local dirt strip, again silence. Switched while slowing down on runway, silence. Parked in front of the hanger, switches fine. I am going to swap filters, test, and then go to next idea. Maybe next time in flight if it fails to switch I will be able to wait and listen for pump…</p>
<p>Mark,</p>
<p></p>
<p>Noticed a similar issue with my engine. I switched in cross country flight today and had a brief, very brief, moment of silence before switching back to pump 1. Tested again while circling over a local dirt strip, again silence. Switched while slowing down on runway, silence. Parked in front of the hanger, switches fine. I am going to swap filters, test, and then go to next idea. Maybe next time in flight if it fails to switch I will be able to wait and listen for pump noise before restarting engine. Maybe.</p>
<p></p>
<p>Ralph</p>
<p>N750RP</p> Ive had the parts on order fr…tag:zenith.aero,2020-07-10:2606393:Comment:7280412020-07-10T19:43:06.409ZMark Pensenstadlerhttps://zenith.aero/profile/MarkPensenstadler
<p>Ive had the parts on order from Wicks for a couple of weeks to complete the 2019-02 SB, but they were on back order. I just received an e-mail yesterday that the parts were shipped out so I should have them in a day or so. So once I complete the install, I'll hope that it solves the problem.</p>
<p>Ive had the parts on order from Wicks for a couple of weeks to complete the 2019-02 SB, but they were on back order. I just received an e-mail yesterday that the parts were shipped out so I should have them in a day or so. So once I complete the install, I'll hope that it solves the problem.</p>