Hawg Driver
Active Member
Hi everyone,
Hoping i could pick the collective brain here at VAF about an issue that has me AOG. RV-4, O-320 (150hp), FP Prop, Ellison TBI.
Starting hearing a hiccup/surge during initial climb on the two previous flights, started a turn back towards airport and it immediately went away. I shrugged it off as some type of vapor lock issues (mistake) but engine ran fine afterwards so I continued on with continued monitoring.
On my last flight, on decent to landing, I pushed throttle up to WOT at an intermediate level-off, and the engine started to choke a bit - not rough, just felt like I was pulling the throttle back. Once I actually pulled the throttle back, the engine "caught" and started to run fine again. Rest of decent/approach/landing was fine. Fuel pressure was normal the whole time.
After fueling up, I took my time with a detailed run up. Each time I pushed to WOT, engine would die, and start running again when I pulled the throttle back. Fuel pressure stayed 4-5 psi...boost pump on/off, changing fuel tanks, all had no effect.
I've had this set up of TBI for 7 years, so nothing has changed recently...and I've put over 100hrs on the airplane since the start of 2022.
I got picked up from my that fuel stop and she's stuck AOG until I can figure out what's wrong. Visual inspection looked fine, no signed of fuel leak, air entering the system anywhere, including on the outside of the TBI.
My only "easy" thing I wasn't able to do was check the last-chance screen to see if somehow it is getting gunked up and won't allow enough fuel to pass at WOT.
Any other thoughts out there of where I should look?
Thank you, everybody.
Hoping i could pick the collective brain here at VAF about an issue that has me AOG. RV-4, O-320 (150hp), FP Prop, Ellison TBI.
Starting hearing a hiccup/surge during initial climb on the two previous flights, started a turn back towards airport and it immediately went away. I shrugged it off as some type of vapor lock issues (mistake) but engine ran fine afterwards so I continued on with continued monitoring.
On my last flight, on decent to landing, I pushed throttle up to WOT at an intermediate level-off, and the engine started to choke a bit - not rough, just felt like I was pulling the throttle back. Once I actually pulled the throttle back, the engine "caught" and started to run fine again. Rest of decent/approach/landing was fine. Fuel pressure was normal the whole time.
After fueling up, I took my time with a detailed run up. Each time I pushed to WOT, engine would die, and start running again when I pulled the throttle back. Fuel pressure stayed 4-5 psi...boost pump on/off, changing fuel tanks, all had no effect.
I've had this set up of TBI for 7 years, so nothing has changed recently...and I've put over 100hrs on the airplane since the start of 2022.
I got picked up from my that fuel stop and she's stuck AOG until I can figure out what's wrong. Visual inspection looked fine, no signed of fuel leak, air entering the system anywhere, including on the outside of the TBI.
My only "easy" thing I wasn't able to do was check the last-chance screen to see if somehow it is getting gunked up and won't allow enough fuel to pass at WOT.
Any other thoughts out there of where I should look?
Thank you, everybody.