Technical 899 Stalling under acceleration

[bean]

Hi all

I have an 899 cinquecento which is causing me a load of problems. It was my daily for a year but started to stall randomly when driving. Most of the time it would restart and drive for longer but one it refused to re start for a while and had to be pushed.

Now it starts normally on the 2nd attempt from cold but runs very rough for a bit. If I open out the throttle to much it just stalls or tries to stall. It does this whether hot or cold.

In the last year its had a new fuel tank, fuel pump and strainer, fuel filter.

I have test the lambda and its reading 0.5v, I've replaced the coolant temp sensor, checked for air leaks, bought a new map sensor and checked the pipe from it. Made no change.

I also had a spare idle position and throttle position sensor which I've changed over and makes no difference.

No lights on the dash. The only thing that makes it improve slightly is unplugging the vacuum pipe from the TB. Otherwise it can't be driven.

Any ideas what to do now?


Thanks
Nathan

 

[purf]

Lambda could be intermittent perhaps? Usually makes the engine flood to full throttle would make it behave for a minute.

If you reset the battery to wipe the ecu - what happens then?

Crack or hole in the exhaust up stream of lambda sensor? making it read lean and then flooding it?

 

[bean]

Lambda could be intermittent perhaps? Usually makes the engine flood to full throttle would make it behave for a minute.

If you reset the battery to wipe the ecu - what happens then?

Crack or hole in the exhaust up stream of lambda sensor? making it read lean and then flooding it?

Thanks for the reply.

I'll check the lambda again tomorrow at different temps, the exhaust was new last year so all good.

I left the ecu unplugged for two days, still the same after!