Howdy,
So I had a serious engine power loss / failure last Friday after picking my plane up from it's annual inspection. I wanted to ask folks about what they think may be the cause of the problem. I have a fair amount of diagnosis data suggesting a fuel flow related issue. Sorry for the long write up and thank you to the kind souls who actually read all the way though.
While climbing out at 2650 RPM, about 130' AGL above the runway, the engine died, restarted, died again, and seemingly restarted. All at the exact moment I was pulling flaps up and had my hand off the throttle. Thankfully the runway was 5200 long and I had a good 10 kt head wind and, most importantly, I elected to use the full 5200' even though it required taxing across a shorter runway and a back taxi on the main runway. I managed to land the plane, with minimal power, on the reaming runway and didn't even need to slam on the brakes. One of the few times I'm thankful the PA-28/32 series drop like rocks. Thank you Karl Bergey for designing such a stable plane.
I didn't do any check lists and barely managed to get a radio call out to tower: "[callsign] coming down". Everything happened so fast and instinct kicked in to "fly the airplane" and "get the attitude down to prevent stall". By then I felt I was in at the apex of a roller coaster knowing the ground was coming in a matter of a few seconds. I remember looking at the throttle quadrant and seeing it was full forward as it should be. And my JPI-EDM 830 showed all the EGTs died at the same time.
After a no flap, limited power landing, I thanked the tower for the full runway and told them I didn't need any special assistance (tower saw everything and I think was as shocked as I was) and taxied back to the shop to speak to the owner. He thought maybe there was some air in the fuel lines. I had extensive work done on the plane, including a new jug, and had the tanks pulled to comply with a service bulletin. I happened to bring my laptop along that day so I was able to download the data from the JPI and confirm that all the cylinders's EGTs dropped at the same time, so it wasn't a cylinder specific issue. Ruling out a cylinder issue got back into the plane and taxied over to the run up area and ran at full power for 90 seconds until the CHTs got to 400 degrees. No problem.
I called it quits for the weekend, snuggled with my four kids, said prayers, and reviewed the flight data. Looking carefully at the 40 seconds from takeoff roll to landing I noticed my fuel flow data on the JPI was odd. As RPM increased to 2650, the fuel flow increased as well but then suddenly stopped and then decreased to ~10 GPH. Normal fuel flow is ~25 GPH. I noticed the fuel flow cut out about 8 seconds after I got the plane moving and at 2650 RPM. The RPM drop occurred about 4 seconds later as I was about 20 ft in the air. Note my JPI takes 2 second sample intervals. See the attached PDF.
I went back to the shop and plane on Monday. After the most extensive pre-flight I have ever done, I couldn't get the plane to start. The fuel pressure gauge went way high, nearly 10 psi when it should be around 6 psi (note, O-540 engine). I eventually got the engine started and taxied over to the shop. After reviewing their fuel related work they noticed that one of the nuts on a fuel line to the fuel selector/drain sump for my in use tank was loose by 3/4 of a turn. We also discovered that the electric fuel pump was damages as the filter/washer/and retaining pin were lose and unseated. See photo. Talking to the tech who worked on it, he said he had a hard time putting it back together during the annual when he cleaned the filter. I think he inadvertently damaged it. In fact, the electric fuel pump stopped working at the shop while the shop owner was testing the plane; he hopped into the plane, pushed the switch and it won't start. The fuel pump was a 1988 Facet automotive one.
So as of today, Wednesday, I'm awaiting a new fuel pump that is TSOed for the plane and I'm hope that indeed fixes the problem. Has anybody else experienced a fuel flow interruption from a malfunction electric boost pump? The Facet pump doesn't appear to have a bypass channel on it. Basically it appears to allow fuel flow through it when the mechanical pump is working. I'm thinking that maybe the impediment in the Facet pump (i.e. a floating washer and retaining pin in the fuel screen) combined with the air from the lose nut simply cut off a good part of my fuel supply.
So I had a serious engine power loss / failure last Friday after picking my plane up from it's annual inspection. I wanted to ask folks about what they think may be the cause of the problem. I have a fair amount of diagnosis data suggesting a fuel flow related issue. Sorry for the long write up and thank you to the kind souls who actually read all the way though.
While climbing out at 2650 RPM, about 130' AGL above the runway, the engine died, restarted, died again, and seemingly restarted. All at the exact moment I was pulling flaps up and had my hand off the throttle. Thankfully the runway was 5200 long and I had a good 10 kt head wind and, most importantly, I elected to use the full 5200' even though it required taxing across a shorter runway and a back taxi on the main runway. I managed to land the plane, with minimal power, on the reaming runway and didn't even need to slam on the brakes. One of the few times I'm thankful the PA-28/32 series drop like rocks. Thank you Karl Bergey for designing such a stable plane.
I didn't do any check lists and barely managed to get a radio call out to tower: "[callsign] coming down". Everything happened so fast and instinct kicked in to "fly the airplane" and "get the attitude down to prevent stall". By then I felt I was in at the apex of a roller coaster knowing the ground was coming in a matter of a few seconds. I remember looking at the throttle quadrant and seeing it was full forward as it should be. And my JPI-EDM 830 showed all the EGTs died at the same time.
After a no flap, limited power landing, I thanked the tower for the full runway and told them I didn't need any special assistance (tower saw everything and I think was as shocked as I was) and taxied back to the shop to speak to the owner. He thought maybe there was some air in the fuel lines. I had extensive work done on the plane, including a new jug, and had the tanks pulled to comply with a service bulletin. I happened to bring my laptop along that day so I was able to download the data from the JPI and confirm that all the cylinders's EGTs dropped at the same time, so it wasn't a cylinder specific issue. Ruling out a cylinder issue got back into the plane and taxied over to the run up area and ran at full power for 90 seconds until the CHTs got to 400 degrees. No problem.
I called it quits for the weekend, snuggled with my four kids, said prayers, and reviewed the flight data. Looking carefully at the 40 seconds from takeoff roll to landing I noticed my fuel flow data on the JPI was odd. As RPM increased to 2650, the fuel flow increased as well but then suddenly stopped and then decreased to ~10 GPH. Normal fuel flow is ~25 GPH. I noticed the fuel flow cut out about 8 seconds after I got the plane moving and at 2650 RPM. The RPM drop occurred about 4 seconds later as I was about 20 ft in the air. Note my JPI takes 2 second sample intervals. See the attached PDF.
I went back to the shop and plane on Monday. After the most extensive pre-flight I have ever done, I couldn't get the plane to start. The fuel pressure gauge went way high, nearly 10 psi when it should be around 6 psi (note, O-540 engine). I eventually got the engine started and taxied over to the shop. After reviewing their fuel related work they noticed that one of the nuts on a fuel line to the fuel selector/drain sump for my in use tank was loose by 3/4 of a turn. We also discovered that the electric fuel pump was damages as the filter/washer/and retaining pin were lose and unseated. See photo. Talking to the tech who worked on it, he said he had a hard time putting it back together during the annual when he cleaned the filter. I think he inadvertently damaged it. In fact, the electric fuel pump stopped working at the shop while the shop owner was testing the plane; he hopped into the plane, pushed the switch and it won't start. The fuel pump was a 1988 Facet automotive one.
So as of today, Wednesday, I'm awaiting a new fuel pump that is TSOed for the plane and I'm hope that indeed fixes the problem. Has anybody else experienced a fuel flow interruption from a malfunction electric boost pump? The Facet pump doesn't appear to have a bypass channel on it. Basically it appears to allow fuel flow through it when the mechanical pump is working. I'm thinking that maybe the impediment in the Facet pump (i.e. a floating washer and retaining pin in the fuel screen) combined with the air from the lose nut simply cut off a good part of my fuel supply.
