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Ross
Ross, Diagnostic and repair technician
Category: UK Car
Satisfied Customers: 1159
Experience:  Licensed diagnostic and repair technician
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Customer Question

hello are you here?

i have corsa 12xep 2008. it has rough idle, or pulsing idle, pulse 1-2 times a second. revs goes up just a little bit, 70-100rmps.can feel car is shaky.

i'm a trader and i can take from good working car any part i need. also have opcom and deplhi and launch machines.

till now i've tried:

map sensor, throttle body, spark plugs, compression test, then took whole intake manifold from another car with all injectors and other bits on intake manifold,tried to remove aux belt, checked timing (with tool)  nothing helped. erased all codes , map sensor comes as faulty sometimes and engine light on. but if i erase it it will come just will couple days, or maybe it came back because i unplugged. map sensor tried from 3 corsas, all same with same part number, no luck.

Submitted: 1 year ago.
Category: UK Car
Expert:  Ross replied 1 year ago.
Hello and thanks for trusting me to help you today. Sorry for the delay in answering your question, I am a licensed diagnostic and repair technician, I look forward to working with you.Based on what you describe as the fault, and the parts you have changed I suspect this may be an ECU Fault. I have come across very similar problems in the past where a fault with the engine ECU is causing these running issues. Before going down the ECU Route, I would advise you to check a few more things. Firstly check the camshaft position sensor on diagnostics using Live data (graph it if possible) to monitor if there is any abnormalities in the signal occasionally I have seen these give unusual signals due to problems with the sensor or the reluctor ring which can cause a blip resulting in this pulsing. If this checks out OK monitor the voltage output from the alternator... I have seen problems with rectifiers upsetting the ECU when the voltage is unstable. If this is all OK, I think the next step would be to send the ECU away for testing, or swap and program a spare ECU... Unfortunately it would need to be programmed so often sending the original ECU away for testing and repair is an easier option. I hope I’ve provided the information you were seeking. If you need more help, please use the reply tab to continue our conversation. If you do not require further assistance, kindly rate my service. Thank you, Ross.
Customer: replied 1 year ago.

well, i took auxbelt out, feed car with extra battery, and same problem persist, also i unplugged camshaft sensor on rununing car, and it make no difference, im not sure but maybe camshaft takes reading only on start up?


i have already booked to main dealer on thursday.they will charge me a lot for reprogram repair ecu..but if it not helps them ahhhhh.