Hi everyone im going to keep this short as i can and hope that someone can recognise this problem. I have s Mazda 6 sport 2.0 diesel with a major problem ill start from the beginning. It all started when the engine gave in the "dreaded injector issue", so off i went and sourced a second hand engine from a breakers and got my mechanic to install it. After he installed said engine and done all the checks he started the car and it ran no problem first time. The major problem is it will not respond to throttle imput at all it just stays at idle or drops below it. We checked the injectors which were reconditiond and noticed the car is only running on two injectors at a time. First we taught the injectors might need to be coded but the car will not recognise the diognostics equipment and the only fault code we got was a u0401 code none comunication with ecu i think it might be somthing else. I have a sneaky feeling it is electric problem ie sensor, faulty wires from install or bad earth. Three lots of mechanics are after looking at it and all got bet on it. I hope some one that reads this can understand this problem and can shead some light on this thanks.

 

When the engine was swapped, did they use all the sensors and wiring off your old engine?

The replaced injectors need to be programed to the old PCM, you can't get around this process.

You either need to find another workshop with a better diagnostic tool or tow it to Mazda and get them to program them.

 

Thanks for your reply and comments grimreaper, My mechanic said he swaped all or most of the sensors from old engine including the fuel pump with sensor to the new one. I think you might be right about the diognostics equipment they are using is not up to scratch i may aswell bite the bullit and send it to a mazda garage.Its turning into a never ending money pit. 😢