Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 40; Flight Crew Total 11000; Flight Crew Type 450
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Fuel Issue
Flight Crew Diverted; Flight Crew Landed in Emergency Condition; Flight Crew Overcame Equipment Problem
Human Factors; Aircraft
During cruise at 6;000 feet MSL; engine began to run erratically and I noticed that the fuel flow was fluctuating between [approximately] 14-19 gallons per hour. I attempted to use the mixture to dampen the changes in fuel flow. I suspected that I had a failing fuel control so I turned the boost pump on low to supplement the fuel flow. I [advised] ATC and elected to divert to ZZZ. I informed ATC of my issue and was provided with great assistance. Approaching ZZZ; I noticed that the fuel selector was not fully in the detent. After moving the fuel selector firmly into the detent; the engine began to run normally and the fuel flow became consistent. I landed in ZZZ and terminated the event with ATC.
BE-36 pilot reported fuel system anomaly in flight. They discovered that the fuel selector was not fully in the detent and after repositioning it; the engine ran normally.