jsisk
Member
I ordered a factory new Lycoming 390-EXP engine for my 14. In late April, the first engine run was a difficult, rough start, and did not last long. I was surprised to see in the post-run inspection black, sooty liquid coming from the exhaust slip joints and blown all over the white engine mount. It rubbed off with my finger and smelled like fuel and exhaust. I suspected an excessively rich mixture. Our troubleshooting included pulling all the fuel injectors. We found that 3 or the 4 had been over torqued at the factory to the point that top of the nozzle inserts had sheered off and were stuck in the B-nut of the fuel lines. The result was an unregulated flow of fuel into the cylinders.
When we contacted Lycoming, they did not have the replacement fuel lines and injectors. They directed us to Airflow Performance for parts, which we had to purchase outright, despite being under warranty. The subsequent warranty reimbursement has been a nightmare and I still waiting 4.5 months later.
My greatest concern here is this: how does a factory engine, presumably assembled with automated tooling, get over torqued during assembly? and how is the problem not realized during a test run for 30-minutes? The test stand data supplied with the engine is VERY scant, no FF or temp data.
This problem seems to be a assembly process problem, so the odds are that my engine is not the only one that was incorrectly assembled and tested without catching the problem. Obviously, one buys a factory new engine to avoid just this sort of problem. I think there is one, higher torque spec for the injector body, and another lesser spec for the fuel line.
If you are having unexplained fuel, leaning, or significant cylinder-to-cylinder temp differences, you may want to check your fuel injectors for this problem.
When we contacted Lycoming, they did not have the replacement fuel lines and injectors. They directed us to Airflow Performance for parts, which we had to purchase outright, despite being under warranty. The subsequent warranty reimbursement has been a nightmare and I still waiting 4.5 months later.
My greatest concern here is this: how does a factory engine, presumably assembled with automated tooling, get over torqued during assembly? and how is the problem not realized during a test run for 30-minutes? The test stand data supplied with the engine is VERY scant, no FF or temp data.
This problem seems to be a assembly process problem, so the odds are that my engine is not the only one that was incorrectly assembled and tested without catching the problem. Obviously, one buys a factory new engine to avoid just this sort of problem. I think there is one, higher torque spec for the injector body, and another lesser spec for the fuel line.
If you are having unexplained fuel, leaning, or significant cylinder-to-cylinder temp differences, you may want to check your fuel injectors for this problem.