Running problems

[Drew]

I know this site doesnt directly cover Unos but im getting desparate. My girlfriends Uno has running problems. It tends to misfire badly almost bringing the car to a halt, but it is very intermittent. Sometimes it will start up fine and drive fine, sometimes it will start up and pull away fine but give up as soon as you hit the main road but after a while get back to normal and sometimes it refuses to start at all. It doesnt mind 1st and 2nd gear but has trouble accellerating through 3rd and 4th.
We have changed, ht leads, plugs, dizzy cap and rotor arm air filter. I have not recently changed the type or brand of fuel. I have changed the lambda sensor and finally had a Fiat garage look at it, they said the ECU was not working and it was water damaged, there was a tiny bit of corrosion on the plug but nothing on the PCB board inside the box. I have ordered another ECU and it hasnt made a scrap of difference. What on earth else can it be?

 

[John]

ecu plug

if there's still some corrosion on the plug give the connector a rub with some wet and dry. Also check you battery earth strap is secure. Hope this helps.

 

[Jon Mills]

Coils?

I know that the Punto had notoriously dodgy coils, causing intermittent misfiring. I wonder if it's the same on the Uno?

I changed the coils on my Punto and it made a huge difference to the smoothness of the running.

Could be worth a try?

Jon.