3 replies to this topic

[green mini cooper]

Could anyone shed any light on why my Mini Cooper 1.3i SPi is not running properly?

It was suffering from what I thought may have been a poor Earth, as there was a few occasions where I was momentarily losing electical power when switching on indicators or putting on the headlights or other elctrical items.

So I went into the boot to check the connections on the battery to find it was actually the Positive terminal that was loose, which was duly tightened.

Since that moment, the car has run very badly, when you turn the key not touching the accelerator it starts but runs very slowly almost stalling.

If you drive it up the road and stop at a set of lights it will idle at 1500 rpm for around 10 seconds and slow down to 800 rpm, then starts to drop even lower, where if you don't blip the throttle it will stall again.

Any help is gratefully received

Matt

[nev_payne]

Don't quite understand why a better-attached battery would result in worser drivability tho.

Well the latter part of your problem (the 1500 to 800) is fairly normal (all be it the 1500 is slightly high). This is the minis auto choke mechanism where the engine is warmed up by having a faster idle untill the engine is warm enough. 800 rpm is about right for normal idle.

Quite why its drooping lower still is a little worrying - could be a case of checking the fuel filter/ spark plug conditions?

[green mini cooper]

Don't quite understand why a better-attached battery would result in worser drivability tho.

You and me both!!

Well the latter part of your problem (the 1500 to 800) is fairly normal (all be it the 1500 is slightly high). This is the minis auto choke mechanism where the engine is warmed up by having a faster idle untill the engine is warm enough. 800 rpm is about right for normal idle.

This is when it's warmed, when it's cold (this morning) it's totally undriveable.

Quite why its drooping lower still is a little worrying - could be a case of checking the fuel filter/ spark plug conditions?

It's almost like something is tripping out, it's idling at 800, and then for a totally inexplicable reason it drops and stalls.


I have a confession, I have fiddled with the screw for the throttle lickage that is controlled by the stepper motor, before I read here that you mustn't touch it, so I think I'll have to book it in to the specialist who sorted it for me last time!

Thanks though for your reply, I'll let you know what the turn out is!

[green mini cooper]

Don't quite understand why a better-attached battery would result in worser drivability tho.

You and me both!!

Well the latter part of your problem (the 1500 to 800) is fairly normal (all be it the 1500 is slightly high). This is the minis auto choke mechanism where the engine is warmed up by having a faster idle untill the engine is warm enough. 800 rpm is about right for normal idle.

This is when it's warmed, when it's cold (this morning) it's totally undriveable.

Quite why its drooping lower still is a little worrying - could be a case of checking the fuel filter/ spark plug conditions?

It's almost like something is tripping out, it's idling at 800, and then for a totally inexplicable reason it drops and stalls.


I have a confession, I have fiddled with the screw for the throttle lickage that is controlled by the stepper motor, before I read here that you mustn't touch it, so I think I'll have to book it in to the specialist who sorted it for me last time!

Thanks though for your reply, I'll let you know what the turn out is!

Quick update.

It was a bad earth. Apparently the poor running after starting was due to the alternater trying to recharge the battery when it should have been turning it's attention to the ECU, causing poor running from start up, when the battery voltage was back up it would run smoothly again. The stalling was due the drop in voltage going from high engine speed back to idle.

Solution was change the earth strap in the boot and clean the mating faces, change the earth strap in the engine bay and clean the faces, then fit a second engine strap for good measure, result, one happy Mini and one even happier Mini owner!

It may be fuel injected, but it's still a Mini. In the old days it was points and carbs to fiddle with, now it's earths and vacuum pipes!!