Technical suspected engine management problem, 55SX (1995)

[alpinista]

Hi there, any technical people out there recognise this problem?

A friend has a 95 Punto 55SX with a strange engine glitch. (Car is used almost exclusively for shopping and low-speed commuting.)

It seems to occur when the car has warmed up, i.e. not immediately from cold. When slowing down from speed (e.g. at lights or behind stopped cars), after coming to a halt the engine revs uncontrollably as if the accelerator was fully depressed. Necessitates turning off engine until time to pull off again.

Problem does not seem to occur if the car is driven without engaging 4th gear and keeping to just under 40 mph.

The throttle cable has just been changed, so that probably is not the source.

Honest John website notes "spate of ECU, lambda sensor, injection potentiometer, temperature sender and throttle body problems" with this model.

Any clues anyone??

 

[frozensolid]

Sounds to me like the choke is sticking. Also if you have just changed the throttle cable, check closely that it has been fitted correctly and not binding. Also check the condition/operation of the return spring.