Bad hesitation on 156 2.0 TS
Have had a bad hesitation problem on my 2.0 156 since I bought it a couple of weeks ago. When cold it will not pull at all under 2750 rpm, then it literally takes off like a turbo coming on boost. When I say doesn't pull at all, I mean it actually slows down if you press the throttle. Only ways around it are sitting letting it warm up, slipping the clutch or dumping it and smoking the tyres - not good on a cold engine!
It also hesitates under this magic 2750 rpm when hot but not to the same extent, and to be honest I don't think it's giving all it's 155 bhp out - it doesn't feel all that quick.
Have changed the variator as it was rattling, along with the cam belt, all pulleys and water pump, also the balancer shaft belt and tensioner. The cam timing is good, set it up with the locking tools.
Thought the plugs might have been on their way out so spuffed out and bought an OEM set - no different.
Have tried disconnecting and plugging the vacuum line to the variable intake manifold doodah, there was plenty of vac in there when I removed it so I'd guess no leaks. Made no difference anyway.
Have also tried a known good Lambda sensor (no change) and unplugging the MAF (actually ran worse).
The engine warning light does not come on apart from the 4 second lamp test on start-up. (ok, it does with the maf unplugged but you'd expect that).
My next guesses are throttle pot or possibly coolant temp sensor, but I'm running out of cash and spares.
It's a shame, as it ruins a really nice car.
Anyone had anything similar or have any ideas? I'd rather not give the car to Alfa and spend £150 finding out that they don't know what's wrong either.
Make something idiot proof and someone will only go and build a better idiot...