Narrative:

Shortly after taking off; while leaning during climb the engine starting running rough. I noticed that cylinder #2 and #4 had no egt. Looked up and saw [an airport] about 7 miles ahead and found frequency and [advised ATC] and made a normal straight in landing. Asked where the maintenance shop was and taxied. Door was locked. Fireman called mechanic and no one picked up. I called my mechanic and discussed the problem. This plane 2 years previously had a similar problem and was found to be a clogged fuel injector. Mechanic asked if I had access to tools. Fireman was able to get access to the hangar and tools.my mechanic told me where the fuel injectors were and how to remove them. Found #2 and #4 were partially blocked and I cleaned them with compressed air. Followed mechanic's instructions to replace the injectors. Started the plane and did a mag check and found that #2 and #4 were working properly on both mags. Later flew plane to mechanic. He called lycoming and felt it best to replace the fuel pump and several components in the fuel system. He also replaced the fuel injectors with the newer style.

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Original NASA ASRS Text

Title: C177RG pilot reported diverting after the engine began running rough. Problem was later traced to partially clogged fuel injectors in cylinders #2 and #4.

Narrative: Shortly after taking off; while leaning during climb the engine starting running rough. I noticed that cylinder #2 and #4 had no EGT. Looked up and saw [an airport] about 7 miles ahead and found frequency and [advised ATC] and made a normal straight in landing. Asked where the maintenance shop was and taxied. Door was locked. Fireman called mechanic and no one picked up. I called my mechanic and discussed the problem. This plane 2 years previously had a similar problem and was found to be a clogged fuel injector. Mechanic asked if I had access to tools. Fireman was able to get access to the hangar and tools.My mechanic told me where the fuel injectors were and how to remove them. Found #2 and #4 were partially blocked and I cleaned them with compressed air. Followed mechanic's instructions to replace the injectors. Started the plane and did a mag check and found that #2 and #4 were working properly on both mags. Later flew plane to mechanic. He called Lycoming and felt it best to replace the fuel pump and several components in the fuel system. He also replaced the fuel injectors with the newer style.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.