- Joined
- Oct 1, 2004
- Messages
- 63
- Points
- 21
Hello to everyone! My car continues to have problems at idle (mono jetronic bosc). When it's cold it works fine (mixture is probably enriched by ECU and I also see throttle position opens a bit through the stepper motor), but as soon as it starts to warming up, idle returns to its default level and engine starts to run rough. This problem is very evident after the first 2 or 3 minutes of working and it diminuishes when the engine is completely warmed up. During this summer and this autumn the problem disappeared with engine completely warm (coolant indicator approx at central values) but now it is present continuatively. In particular if I stop the car for any reason I can listen the idle r.p.m. to diminuish and then it is incremented. If I accelerate and then I relase the accelerator I see the same problem. If I leave the car at idle for a minute, idle is correct but sometimes it diminuishes without reasons. Sometimes the engine cuts out. I did a lot of checks, I also changed coolant sensor and vacuum advance but the problem still remains. I checked Lambda voltage and it's correct when I go on road pushing accelerator with a gear (it changes rapidly). But Lambda voltage is very low at idle (0.1 - 0.2 V) and sometimes it rises up to 0.7 0.8, then it diminuishes another time. Idle problems start when lambda voltage is low. SO I' m sure that it's a problem of LEAN MIXTURE at idle!!! But I can't find any air leacks... where I can search for some air connection loose or similar? Or what can cause this lean mixture only at idle? Engine works fine an all the others working conditions!!!