Technical Engine stopping.

[Corblimey]

The problem is occasionally the engine stops when changing from second gear to neutral and is fine on other gear changes. There are no engine fault codes and a fiat dealer fitted new spark plugs, fuel injectors and ignition coil, but the fault remains. The throttle control body has also been thoroughly cleaned and reset and the car accelerates well and drives perfectly on motorways. Any suggestions on what the fault is would be much appreciated.

 

[varesecrazy]

Hi,
has the battery to Chassis Black earth cable been replaced?

 

[Corblimey]

Hi,
has the battery to Chassis Black earth cable been replaced?

Thanks for your reply. I am unsure if it has been replaced or not as the car was bought second hand. Where is this cable located please ?

 

[varesecrazy]

Thanks for your reply. I am unsure if it has been replaced or not as the car was bought second hand. Where is this cable located please ?

It's the black cable on the battery,

It connects to the chassis and the gearbox

Not unusual for the copper wire inside it to become green mush.., no longer passing electricity

So intermittent running, as the engine and gearbox moves

 

[Corblimey]

A new cable has now been fitted and the contact points to the gearbox housing and body cleaned with a wire brush. The original cable is corroded, but the fault remains.

 

[ZaphodB]

occasionally the engine stops when changing from second gear to neutral and is fine on other gear changes

Do you do that often?

You're saying it's fine on other gear changes, but how about other gearchanges to neutral

 

[Herts Hillhopper]

What’s not clear here is when you are moving to neutral… do you mean when coming to a stop (eg at a junction)? If so, is it not the stop/start function turning the engine off?

 

[ZaphodB]

What’s not clear here is when you are moving to neutral… do you mean when coming to a stop (eg at a junction)? If so, is it not the stop/start function turning the engine off?

Swot I was kinda thinking and what I was getting at , but I'm not fully au fait with the fiat range just yet, so I didn't know if this model or indeed model year had stop/start or not.

It would certainly explain the "occasionally", as stop/start systems have various criteria (battery voltage, clutch pedal position, brake pedal pressure to name just a couple) they have to meet before engaging, i.e. they won't engage every time.

If it doesn't have SS, then obviously we'll have to pursue different things.

 

[Panda IIs]

Swot I was kinda thinking and what I was getting at , but I'm not fully au fait with the fiat range just yet, so I didn't know if this model or indeed model year had stop/start or not.

It would certainly explain the "occasionally", as stop/start systems have various criteria (battery voltage, clutch pedal position, brake pedal pressure to name just a couple) they have to meet before engaging, i.e. they won't engage every time.

If it doesn't have SS, then obviously we'll have to pursue different things.

Well if it has SS then there's a button to disable it? My SS (when it has the inclination to work) does switch engine off just as the car is rolling very slowly to a halt but not when there is any significant wheel rotation.

If the OP means he knocks the car into neutral while rolling at any significant speed then that's not great driving practice but maybe indicates a throttle body that needs cleaning?

 

[Corblimey]

Do you do that often?

You're saying it's fine on other gear changes, but how about other gearchanges to neutral

Mostly engine stops from second gear to neutral and occasionally third to neutral.

 

[Corblimey]

What’s not clear here is when you are moving to neutral… do you mean when coming to a stop (eg at a junction)? If so, is it not the stop/start function turning the engine off?

It does happen when slowing to approach a junction. The car does not have stop/start function.

 

[JaffaOrange]

Just a guess/something to check: there must be a cut out somewhere in the car which prevents the car from starting in gear. Perhaps the gear lever movement affects a faulty switch somewhere near the gear lever or gearbox. Just a thought…

 

[ZaphodB]

Bizarre

What if you if (vehicle completely stationary at home, engine running) just run through (slowly) the gears and bring back to neutral each time?

 

[AnthonyH]

The problem is occasionally the engine stops when changing from second gear to neutral and is fine on other gear changes. There are no engine fault codes and a fiat dealer fitted new spark plugs, fuel injectors and ignition coil, but the fault remains. The throttle control body has also been thoroughly cleaned and reset and the car accelerates well and drives perfectly on motorways. Any suggestions on what the fault is would be much appreciated.

I don't believe there are no engine codes.

The garage you are using has a cheap or faulty code reader. Get them read somewhere else.

 

[Panda IIs]

It does happen when slowing to approach a junction. The car does not have stop/start function.

It sounds like a fuelling issue; when was the air filter last changed? And as above, see if the throttle body needs a clean. Maybe check for leaks in the intake and any vacuum lines too.

 

[Corblimey]

It sounds like a fuelling issue; when was the air filter last changed? And as above, see if the throttle body needs a clean. Maybe check for leaks in the intake and any vacuum lines too.

Thanks to everyone for the replies. I have recently fitted a used replacement throttle body and the air filter is clean and in good condition. There are no loose or split vacuum pipes. Still the same problem and the engine also stopped today when changing from neutral to reverse gear.

 

[ZaphodB]

I have recently fitted a used replacement throttle body

reason why ?

 

[JaffaOrange]

Thanks to everyone for the replies. I have recently fitted a used replacement throttle body and the air filter is clean and in good condition. There are no loose or split vacuum pipes. Still the same problem and the engine also stopped today when changing from neutral to reverse gear.

 

[JaffaOrange]

This sounds very much like an electrical issue to me. Suddenly cutting out when under no load and moving the gear-lever and clutch pedal causing the engine to cut out. The OP stated it runs and accelerates well on motorways which doesn’t sound like fuelling.

 

[JaffaOrange]

And thinking a bit further on this, perhaps move the gear-lever about and clutch pedal while stationary with the engine running and see if you can replicate the error. Nothing to lose and you might at least rule something in or out.