Buckaroo Posted May 11, 2017 Report Share Posted May 11, 2017 This morning I went to fly my CT and at run up experiences wild fluctuations in my psi. Aborted the flight. Any thoughts from the community? Thanks Dave IMG_4389.MOV Link to comment Share on other sites More sharing options...
Tom Baker Posted May 11, 2017 Report Share Posted May 11, 2017 The movie wouldn't play on my computer. 4.7 is not out of line on the fuel pressure, especially if you have the new style fuel pump. If you do have the new pump the ranges should have been changed on your Dynon. Link to comment Share on other sites More sharing options...
Roger Lee Posted May 11, 2017 Report Share Posted May 11, 2017 I agree with Tom. Those settings on your instrument are wrong. The old fuel pressure limit was 5.8 psi and the new limit is 7.2 psi. Go into the menu and change the limits. If this had been a wild pressure fluctuation then: I doubt you had a real problem. It's most likely a loose connection and possibly the sender. Pop the cowl and slide the fuel pressure connectors off then slide them back on, then gently squeeze the connectors on the fuel pressure sender even if they feel snug. p.s. I think part of the problem with the digital age today is the show me everything which now means people need to be able to interpret how each item affects the other and when one reading is off what should be going on. Most of the time if one item goes whacky then it should affect another reading or the engine performance. As an example: What if you didn't have a fuel pressure indicator at all on any instrument. You would have flown the plane unless there was a real indication of a problem. p.s.s Make sure you have the current 5.6.1 Dynon software version while you're at it. Link to comment Share on other sites More sharing options...
Buckaroo Posted May 11, 2017 Author Report Share Posted May 11, 2017 I'm trying to get the movie up it really doesn't matter. Vision the needle swinging hard left and right 2 lbs to yellow 5.5 every second or so. Link to comment Share on other sites More sharing options...
Buckaroo Posted May 11, 2017 Author Report Share Posted May 11, 2017 Roger where abouts is the sender connection? Thanks Dave Link to comment Share on other sites More sharing options...
Roger Lee Posted May 11, 2017 Report Share Posted May 11, 2017 If this had been a wild pressure fluctuation then: I doubt you had a real problem. It's most likely a loose connection and possibly the sender. Pop the cowl and slide the fuel pressure connectors off then slide them back on, then gently squeeze the connectors on the fuel pressure sender even if they feel snug. Link to comment Share on other sites More sharing options...
Buckaroo Posted May 11, 2017 Author Report Share Posted May 11, 2017 2 hours ago, Roger Lee said: If this had been a wild pressure fluctuation then: I doubt you had a real problem. It's most likely a loose connection and possibly the sender. Pop the cowl and slide the fuel pressure connectors off then slide them back on, then gently squeeze the connectors on the fuel pressure sender even if they feel snug. I will thanks! Can you tell me the approximate position of those wires under the hood please? Thanks Dave Link to comment Share on other sites More sharing options...
Tom Baker Posted May 11, 2017 Report Share Posted May 11, 2017 It should be mounted on the firewall kind of below the battery. Link to comment Share on other sites More sharing options...
Buckaroo Posted May 11, 2017 Author Report Share Posted May 11, 2017 Thanks Tom I'll check it out! Tom where are you located? Can you recommend a service center the closest to me in Montana? Link to comment Share on other sites More sharing options...
Tom Baker Posted May 11, 2017 Report Share Posted May 11, 2017 I'm in Southern Illinois. I would figure out which Rotax distributor covers your territory, and check with them for service centers in your area. Link to comment Share on other sites More sharing options...
Buckaroo Posted May 11, 2017 Author Report Share Posted May 11, 2017 Here's the movie of my PSI situation this morning. The amps are responding to the psi fluctuation. Tomorrow I will reset the 120 to 7.3 psi and make sure my wires are crossed I mean connected!? Link to comment Share on other sites More sharing options...
Anticept Posted May 12, 2017 Report Share Posted May 12, 2017 Your connections are bad or pressure sender have gone bad. Link to comment Share on other sites More sharing options...
Buckaroo Posted May 12, 2017 Author Report Share Posted May 12, 2017 49 minutes ago, Anticept said: Your connections are bad or pressure sender have gone bad. Thanks I'll check and advise! I'm hoping to learn the Dynon reset to 7.3 psi. Link to comment Share on other sites More sharing options...
Roger Lee Posted May 12, 2017 Report Share Posted May 12, 2017 I'm fairly certain it's a bad connection. I have seen this before. Link to comment Share on other sites More sharing options...
Buckaroo Posted May 12, 2017 Author Report Share Posted May 12, 2017 I'm at the aircraft don't see any wires under the battery but plenty above it. Maybe with my pics someone can zero in on that wire? Thanks everyone! Link to comment Share on other sites More sharing options...
Tom Baker Posted May 12, 2017 Report Share Posted May 12, 2017 OK, I went back and looked at the pictures you posted for review of your engine. The spot where the fuel pressure normally comes from is plugged off. Something else I noted as odd is the pressure accumulator is missing from the fuel line from the pump to the fuel distribution block. however there is a T fitting there. I think the line from the T fitting will run to the fuel pressure sending unit. These oddities has me wondering if your airplane had the Dynons added here in the states rather than at the factory. Link to comment Share on other sites More sharing options...
Buckaroo Posted May 12, 2017 Author Report Share Posted May 12, 2017 Thanks for the reply Tom! I guess the question I have now is can I fly my plane with this fluctuation or am I screwed now with no repair facility within 500 miles? Link to comment Share on other sites More sharing options...
Tom Baker Posted May 12, 2017 Report Share Posted May 12, 2017 You don't need a Rotax service center for the fuel pressure issue. Any A&P mechanic should be able to take care of the issue. Check the wires on the sender that is above the oil tank in you picture first. If that doesn't fix it I would replace the sender, but you could check pressure with a mechanical gauge if you wanted. The sender is a VDO 360-043 Link to comment Share on other sites More sharing options...
Buckaroo Posted May 12, 2017 Author Report Share Posted May 12, 2017 24 minutes ago, Tom Baker said: You don't need a Rotax service center for the fuel pressure issue. Any A&P mechanic should be able to take care of the issue. Check the wires on the sender that is above the oil tank in you picture first. If that doesn't fix it I would replace the sender, but you could check pressure with a mechanical gauge if you wanted. The sender is a VDO 360-043 I will try to find a bum connection. Thanks again Tom! I owe you a ? Link to comment Share on other sites More sharing options...
Buckaroo Posted May 13, 2017 Author Report Share Posted May 13, 2017 20 hours ago, Tom Baker said: You don't need a Rotax service center for the fuel pressure issue. Any A&P mechanic should be able to take care of the issue. Check the wires on the sender that is above the oil tank in you picture first. If that doesn't fix it I would replace the sender, but you could check pressure with a mechanical gauge if you wanted. The sender is a VDO 360-043 Went out to the plane today and pulled the two wires off the sensor and reattached them. The top one pulled off unusually easy. Cranked her up and everything seems to be in line. Thanks to this amazing forum for the tip!? Link to comment Share on other sites More sharing options...
Tom Baker Posted May 13, 2017 Report Share Posted May 13, 2017 You might want to try and tighten the connector on the end of the wire, so it fits tighter on the terminal. Link to comment Share on other sites More sharing options...
Buckaroo Posted May 13, 2017 Author Report Share Posted May 13, 2017 Yes Tom I squeezed it tighter. Thanks for caring!? Link to comment Share on other sites More sharing options...
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