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Matt, Engineer
Category: Car
Satisfied Customers: 20361
Experience:  Honors degree in Mechanical Engineering, worked 8 years as a Formula 1 engine engineer.
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runs ok..well, it dies and needs to be nursed..fuel filter..dash board

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have a cinquecento sporting that runs ok on idle and when cold, but as soon as it is warm the engine doesn't want to run at all well, it dies and needs to be nursed back to a safe place... Checked so far:
cat is OK
New temperature sensor
water in tank removed and fuel filter replaced
throttle position switch replaced

no error light shows up on dash board

I'd start by checking the connectors MAP ( manifold Absolute Pressure) sensor thats mounted on the inlet manifold

its this that provides the load input into the ECU and if faulty would mean that you'll get incorrect levels of fuel coming through

unplug it and give the connectors a spray with contact cleaner
And also unplug the wiring loom connections in the engine bay one at time and inspect for corroded or recessed pins.

Also its worth checking that the electric pump that feeds the injectors is working correctly, it should run for a few seconds then switch off when you first turn the ignition on. If the connections to this are corroded or damaged then the pump could stop at any time. Check that its relay switches in and out and the relay contacts are clean and bright – replace the relay if in any doubt and do the same for the fuse, ideally measure the voltage at the pump and check its getting 12V

Also check for exhaust leaks before the o2 sensor as if this has been experiencing an exhaust leak then it will have been running very rich as the sensor will see the extra air pulled in as fresh / lean fuelling and be adding fuel to compensate.

this can lead to catalyst failure as the extra fuel can re-light inside and melt the catalyst

The best way to find an exhaust leak is to run the engine from cold and feel around the exhaust joints with your bare hands - you'll have about 30 seconds before it all gets too hot and you should feel any escaping gas blowing over your fingers
Matt and 6 other Car Specialists are ready to help you
Customer: replied 4 years ago.
Hi, and thanks,

Will take a look asap and hit the accept button on investigation.

Let you know soon.
No problem

just get back to me on this post

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