Dodgy running - heat related!
Okay, this is the 3rd summer running!
Bought my 2.0 TS in August 2005. It runs fine and dandy most of the time. However, it has a temperature related issue which has just reared its ugly head again!
When the ambient air temperature is hot, or the car has been sat in the sun for a while, the engine runs badly for the first 5-10 minutes of driving at best, and for the whole journey at worst.
Last summer I replaced the MAF with a moody replacement which didn't help, and then a pattern replacement which didn't help either. All exhibited the same problems. In the autumn, winter and early spring, no problems at all!
Now the weather is warming up, the hesitation until about 3000rpm is back. At 3000 rpm it pulls like a train, no hesitation at all.
The plug leads are sound and the plug holes are clean and dry. Its plugs are only 1 year old and the extremely expensive type! The cambelt, all tensioners etc. where replaced last year and work fine in the cold!
Was thinking air temperature sensor, but I don't know where it lives on a 156 Sele.
Any ideas gratefully received.