Triumph Repair: TR6 engine problem, combustion chambers, spray pattern

Question
My TR6 PI engine runs very unevenly, especially at low revs where it is struggling to gain momentum, and it is close to stalling from standstill. The driveshaft tunnel runs very hot which may be part of the problem?

Answer
Hi Henrik,
Any time you have a engine running problem you need to start by confirming that the combustion chambers are ok. First run a compression test. (throttle open) and give me the readings.

If the compression test shows good then you need to do a "Cylinder Kill test" Short each plug and note the RPM change. Any shorted cylinder that does not change the RPM is a dead cylinder and that one must be looked at in the distributor cap, plug wire and spark plug. If they all test good you need to look toward the injection system.

If you ID a dead cylinder or more, remove that injector and hold it in a glass jar so you can see the spray pattern when you start the engine. It should be a 60 degree cone shaped pattern with no dripping or dribbling. If it is not good switch the line and injector with a known good one from another cylinder to test. This is a test of the pump. If a good injector from another cylinder works in that position then you know for sure that the injector is the problem. (sometimes soaking it is injector cleaner will correct it) If that don't correct it you need to replace it.

Howard