Year of Manufacture *: 2005
( Optional ) Engine Code or CC: Zetec
The symptom is that the engine goes down (loses power), while you are pressing accelerator and REVs are below 3000RPM. After 3000 the car goes quite normally.
Connecting scan tool I can see engine runs on idle in closed loop, both O2 sensors are varying from 0.2 to 0.9 volts and values of long and short fuel trim not access 1-2%. I think it is quite normal. On idle the only thing disturbing me is “engine load” - this parameter is 42% (I think it’s too much for idle).
Strange things start on go. Starting acceleration on 1st gear engine loses power. According to scan tool: TPS value is about 50%, engine load is 100%, short term fuel trim value quickly increases up to 33%, both O2 show 0,02 (it’s extremely lean!).
I replaced MAF sensor, and nothing is changed. It seems that something wrong with fuel system and ECU can’t compensate lean mixture. But how to explain rather good performance on REVs above 3000RPM?
Do you have any idea wat’s happening?
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