Hi everyone! This is my first post here but sadly it is of a technical nature trying to diagnose a problem. I have an intermittent fault with my sigma 150 where occasionally at low RPM (<3000) and light throttle, it will hesitate, bog down and refuse to rev instead of picking up and accelerating. This will be accompanied with increased burbling and popping from the exhaust. Giving it full throttle will seem to push through this and the car will accelerate as expected. I have experienced this 3 times during my 170 miles of ownership and each time the car will continue to do it until I switch the engine off for 5 minutes. Upon restart it will be back to normal. Its worth noting that 2 of these times were immediately after a period of spirited driving. Am well aware of the many issues surrounding the sigma 150 engine and have done plenty of searching and reading up about it. However most of the other issues are around lumpiness, drivability and cold running. My car runs perfectly nearly all the time (apart from when it does the above) so I'm not sure if this is down to general 150 quirkiness or something different. Thanks for your help. Martyn.
