luv2flypilot
Well Known Member
My RV-7A has just about hit the 10 hour mark and I have started having some engine issues in the last few hours. I first noticed it on Friday when I was staying in the pattern and working on full stop landings and heard some back firing and engine roughness when I pulled back the power to turn base to final. After I landed I performed a run up and it seemed to be running a little rough. I then cleaned the fuel injectors and well as checked the plugs. Nothing appeared to be wrong with what was found. Did another run up and everything seemed to be fine. I flew it for about an hour and did not appear to have any problems until I came in for landing and started hearing bad back-firing on final when I pulled back the power to around 15 MP. I did some research on here (VAF) Friday night and read that the "Shotgun Approach" was normal with an RV that has Vetterman exhaust (like I have) and was caused from unburned fuel, so I decided not too worry too much about it (however this was the first time I have heard this). Also, I should mention that from the start I have had intermittent issues with abnormal high EGT temps on #3, however the CHT temps seemed to be normal so I did not worry about it and thought that maybe I had a bad sensor and was planning on swapping it with another sensor to see if the problem followed. Yesterday when I went to go fly, I did my run up and everything seemed to be just fine. The only issue was the intermittent EGT temp going up around 1650 to around 1750 during the run up, but stabilized on normal idle . On take off and climb at about 150' and around 3/4 down the runway I heard a few backfires. I started looking for a good spot to put her down in the event I lost the engine since I knew I would not make it back to the runway at that point. I slowly pulled back on the power to around 70% and reduced my climb attitude and the backfiring stopped. I was able to keep a tight pattern and get back and land, but it did not seem to be running very smooth. I was worried about pulling back off the power until I new I could make the runway, so I slowly pulled back when I knew I would make it and kept a little power in until I was over the numbers. When I pulled power back right before flare, the engine never stopped but I thought it was going to by how rough it was running. While taxiing back to my hanger I leaned it a little, however it still sounded like a "Harley" popping and sputtering. An A&I on the airport that heard and saw what happened and said he thought it was running too fat and that I may have a timing issue, but was not familiar with the dual LASAR ignition I have. From what I have been reading the last day or so, it looks like I will have to get a hold of a syncro timing tool in order to check the timing or to see if it is possibly that the LASAR ignition is the problem. Today I went back and cleaned my fuel injectors again as well as checked the plugs again and did not see anything that appeared to be abnormal. I tried to do another high RPM run up and found the engine still seemed to be running rough at high RPMs and will not stay running at idle with quit a bit of sputtering and backfiring at low rpm below 900-950 RPM. It seems to run the best around 1300-1400 RPM, but not as smooth as it should. I plan on calling Eagle Engines tomorrow (where I purchased the brand new engine) to see if they have some recommendations. If anyone has any suggestions that could help me out, it would be greatly appreciated.
The following is my engine set up:
Engine: IO-360-B1BC3, 9 to 1, Roller Lifters, Flow Matched Cylinders, Dual Unison LASAR Ignition, Sky-Tec Starter, Silver Hawk Fuel Injection
The following is my engine set up:
Engine: IO-360-B1BC3, 9 to 1, Roller Lifters, Flow Matched Cylinders, Dual Unison LASAR Ignition, Sky-Tec Starter, Silver Hawk Fuel Injection
Last edited: