Mint imperial 0 Report post Posted December 17, 2012 Hi there, I have an Alfa 147 2.0 ts and I keep getting the Motor Control Failure warning light. Alfadiag shows faults of random misfire so I started chasing ghosts! When I look at the knock sensor plot it shows as inactive - is this normal? Any advice gratefully recieved. Thanks Quote Share this post Link to post Share on other sites
Smaky 73 Report post Posted December 18, 2012 LPG causes havoc with TS engines as LPG has totally different burn characteristics to petrol and the second spark doesn't do anything, if you run it on petrol for a while and forget about using LPG you'll probably find there is no fault. LPG is NOT cheaper in the long run with these engines, it causes pre-ignition, overheating of the cylinder and burns the valve seats out quicker, it is quite possibly the worst thing which could be done to a Twinny. Quote Share this post Link to post Share on other sites
Mint imperial 0 Report post Posted December 21, 2012 Hiya Smaky, I was hoping you'd post on this one Oddly, I had no problem with the lpg in over 65k miles when it was fitted to my old 147. I swapped cars for a sele back in march and swapped the lpg kit too. As you rightly say it runs dandy on proper petrol but misfires on gas. The misfire is now consistent on cylinder 2 and having swapped a couple of coil packs about I can eliminate that. My real suspect now is the timing. I changed the timing belt just after I got the car and reckon I did a crap job I will update after I have tinkered some more! Feel free to pop round and laugh at my mechanic skills anytime, I'm only in Wootton Bassett! Mike Quote Share this post Link to post Share on other sites
Smaky 73 Report post Posted December 21, 2012 If it's misfiring on only one cylinder and you've done the coil pack then it may be lead or plug related, but due to the LPG I'd say do a compression test as it may be melting a piston. Quote Share this post Link to post Share on other sites
