Rough idle (tried everything)
I have 156 1.8 TS 1998 and a week ago when I wanted to change the radiator it started to act weird, the most annoying was the rough idle, from 500 to 1500 rpm. Changed the radiator, everything went fine but still rough idle. The same thing happened when I swapped the engine and a friend told me that it is MAF and I changed it and everything was great!
Tried: changing the MAF, diagnostic-no errors, cleaned the throttle body, made patches on air inlet after the MAF, checked for air leaks on inlet manifold and air inlet-NOTHING MADE THE SITUATION BETTER. The only thing that I have found was that when the car is idling (rough) the lambda sensor sends a 459 mV signal and it isn't changing, it stuck there even when I put my foot on accelerator. MAF is sending the signal od 1,5 to 1,7 volts, depending on the accelerator position. When I try to drive it, my exhaust is busted after the lambda so I hear terrible noise when accelerating, small explosions and the acceleration is not so good. Maybe something will happen after welding the exhaust but I wouldn't put my money it.
I know that there is a bunch of same issues and topics on the forum but I tried to find a solution, googled it, searched the forum, nothing helped...I don't have an Alfa specialist so it is up to me and my cousin (car mechanic) to find the solve the problem.