Murray sibbeston Posted May 24, 2023 Report Share Posted May 24, 2023 I just bought a 2006 ctsw. After flying it home over three days and 24 hours airtime of flawless operation it now has been indicating low fuel pressure. I checked all the fuel lines and found three so loose I could pull them off with my fingers. I fixed this and the pressure was fine for a test flight. But the next flight it happened again. All lines are tight. I suppose my next step is to check the pressure with a gauge? The filters are half full after the short flight. is this normal? Quote Link to comment Share on other sites More sharing options...
GrassStripFlyBoy Posted May 24, 2023 Report Share Posted May 24, 2023 I have an '06 SW, and no that's not normal. Appears someone installed filter in that section of line from the tank down run to the firewall T fitting. This likely was done to relocate the factory filter which is a single filter past the shut off valve in the cabin center tunnel area. Is there a second filter on the other side / tank? I think relocating filters developed a rise in the line and that high spot is holding vapor bubble. Having a plastic filter in engine area is not safe, that could leak easily and far from fire safe too. Quote Link to comment Share on other sites More sharing options...
Madhatter Posted May 24, 2023 Report Share Posted May 24, 2023 Plastic filters in engine compartment is crazy not to mention a choke point. It might be prudent to look closely over the rest of the plane. Anyone that puts these filters in may have done other stupid things. These filters look like something you would put on a lawnmower. Find a real mechanic very familiar with a CT and have him look at it. Quote Link to comment Share on other sites More sharing options...
Roger Lee Posted May 24, 2023 Report Share Posted May 24, 2023 FD published a bulletin many years ago and got rid of plastic fuel filters. There should only be one fine filter in the instrument panel and then the gascolator out in the engine compartment. Plus a plastic fuel filter should not be in the hot engine compartment. Quote Link to comment Share on other sites More sharing options...
Murray sibbeston Posted May 24, 2023 Author Report Share Posted May 24, 2023 The 5 year rubber was just completed so maybe they were put on then. I just bought the plane. I’ll replace the lines. There is a filter on each side. I’ll check to see if the factory filter is still there. It’s my first rotax 912 so I’m not familiar with what is normal. But the filters looked a little Mickey Mouse. They were pretty warm to the touch. I found the fuel lines finger tight so I know I need to double check everything. Quote Link to comment Share on other sites More sharing options...
FredG Posted May 25, 2023 Report Share Posted May 25, 2023 What pressure is indicated that is being considered "low"? Is low fuel pressure transient or is it consistently low? Quote Link to comment Share on other sites More sharing options...
Murray sibbeston Posted May 25, 2023 Author Report Share Posted May 25, 2023 The 5 year rubber was just completed so maybe they were put on then. I just bought the plane. I’ll replace the lines. There is a filter on each side. I’ll check to see if the factory filter is still there. Quote Link to comment Share on other sites More sharing options...
Murray sibbeston Posted May 25, 2023 Author Report Share Posted May 25, 2023 Im not used to the bar readout. It was in the yellow and making the alarm flash. can someone tell me exactly how I find the fuel filter? I don’t want to start pulling apart the dash unless I know I’m on the right track. Also is the proper fuel line 5/16? I’ve read a few posts about putting the filter in a more accessible location so I will probably try that once I access it and see how it’s plumbed in there. thanks. Quote Link to comment Share on other sites More sharing options...
Jacques Posted May 25, 2023 Report Share Posted May 25, 2023 Murray, I'm gonna send you some pictures by email...Meantime, remove these filters....this is a NON approved modification and not permitted on the AULA.(advanced ultralight) ....... the original hose is Wurth 7.5 mm Quote Link to comment Share on other sites More sharing options...
Murray sibbeston Posted May 28, 2023 Author Report Share Posted May 28, 2023 Fredg the lowest pressure was 0.06 bar. It drops in the climb out and it stays Below normal in the entire circuit. I’ve not left the pattern. The pump has ac stamped on it. Is this the older style I may need to replace? Quote Link to comment Share on other sites More sharing options...
Jacques Posted May 28, 2023 Report Share Posted May 28, 2023 if it's gold....it's old.... absolutely change it for the newest....actually , it SHOULD have been done at the rubber change https://electricmotorglider.com/wp-content/uploads/2018/09/912-Fuel-Pump-Web.pdf https://www.rotax-owner.com/en/videos-topmenu/free-videos/424-fuelpump Quote Link to comment Share on other sites More sharing options...
FredG Posted May 29, 2023 Report Share Posted May 29, 2023 If I converted correctly, that's 0.9 psi. No fuel pump at all gets about 0.9 psi from head pressure alone. One of the mechanics can let you know if the pump is the older style. Do you log books indicate that the pump has ever been changed? Have you done a fuel flow test to see if there are any obstructions upstream of the gascolator? Quote Link to comment Share on other sites More sharing options...
FlyingMonkey Posted May 31, 2023 Report Share Posted May 31, 2023 On 5/27/2023 at 11:34 PM, Murray sibbeston said: Fredg the lowest pressure was 0.06 bar. It drops in the climb out and it stays Below normal in the entire circuit. I’ve not left the pattern. The pump has ac stamped on it. Is this the older style I may need to replace? Were you able to make full rpm on climb out at that pressure? Sounds awfully low if as FredG says it's 0.9psi. With pressure that low I'd expect some reduction in power... Quote Link to comment Share on other sites More sharing options...
Murray sibbeston Posted June 2, 2023 Author Report Share Posted June 2, 2023 It ran prefect. No loss of power at all. I took it for a flight in the morning when it was cool and no problem. It’ must be a bad sender I suspect. Quote Link to comment Share on other sites More sharing options...
Roger Lee Posted June 2, 2023 Report Share Posted June 2, 2023 If you have a Kavlico fuel pressure sender then you need to remove the silicone insert at the plug.. It's a Dynon service bulletin ans affects other instruments like Garmin,,, ect, and leaving the silicone insert in causes low fuel pressure indications due to the pressure differential caused by the silicone insert. Quote Link to comment Share on other sites More sharing options...
Jacques Posted June 2, 2023 Report Share Posted June 2, 2023 https://dynonavionics.com/bulletins/support_bulletin_120414.php don't know what sender he has,,, but I know he has ''that thing '' who looks like a trailer ball ...not sure what it is... can you explain please just curious here is a picture of HIS engine I took in 2011 the ''thing'' is in the firesleeve circled green THANKS Quote Link to comment Share on other sites More sharing options...
Anticept Posted June 2, 2023 Report Share Posted June 2, 2023 CTSWs have pulse dampeners (accumulators) on the fuel line to the fuel pump. Not sure why they are there, but that's what they came with. Might have been something to address an issue with the old pierburg pumps. Quote Link to comment Share on other sites More sharing options...
Jacques Posted June 2, 2023 Report Share Posted June 2, 2023 thanks....it came with the AC pump Quote Link to comment Share on other sites More sharing options...
Roger Lee Posted June 2, 2023 Report Share Posted June 2, 2023 The old AC fuel pumps should be replaced. The fuel bulb dampeners on the CTSW's were installed because the original Dynon software had pulsation issues. That is long gone and I remove all CTSW fuel bulb pulsation dampeners. They are not needed any longer. Quote Link to comment Share on other sites More sharing options...
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