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Matt
Matt, Mechanical Engineer
Category: Mercedes
Satisfied Customers: 22160
Experience:  BEng hons Mech engineering, in auto industry 22 years
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My merc vito 116 plays up starting.sometimes it will start

Customer Question

My merc vito 116 plays up starting.sometimes it will start instant. Another time it winds over a while to start and the engine management stays on. And sometimes you turn key and theirs nothing there. Go back to it and it will start. Auto Lecs say different things. Even suggested ecu. Sent ecu to Derby ecu testing. No issues. Come back still problem. Doing my head in now. Would main merc dealers be able to find out on diagnostic
Submitted: 3 months ago.
Category: Mercedes
Expert:  Matt replied 3 months ago.

hello

to get an intermittent start like this I'd say its likely that the crank position sensor is faulty

or the wiring to it is corroded or damaged

if this is Ok then also worth checking the connections to the fuel pump for the same reason - unplug each in turn and give them a good squirt of switch / contact cleaner - Not WD40

and also unplug and inspect the main power relays and fuses for signs of overheating or corroded terminals - so the ones for the ECU and the fuel pump

And also unplug the wiring loom connections in the engine bay one at time and inspect for corroded or recessed pins.

Expert:  Matt replied 3 months ago.

Hi
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