MPi Mini cutting out - any ideas....

[S Works]

Hello all,

My girlfriends Cooper MPi is having 'issues' keeping revs at times leading to engine stalling.

Common scenario, approaching traffic lights, slowing down and as you dip the clutch to pull up to a complete stop the revs drop off, try to even off, battery light and oil light come on and engine cuts out.

Checked the oil and it's fine, battery charge seems alright too as it's not affected by extra drain of electrics running (tryed various combos of lights, radio, heater on etc). Also not a petrol issue as it does it with a full or partially filled tank.

I think I read somewhere before that this is typical of MPi's sometimes (ECU or sensor problem somewhere?).

Used to happen very rarely with the S Works too.

Any ideas? The little b#gger is going in for a service next week and I'd like to prime the guy (family friend, good mechanic, non mini specialist) with suggestions if anyone on here has any good tips.

Cheers,

Tim

[swindorski46]

Yup, mine did this too, exactly the same.

It was still under warranty at the time but even so it took rover about 6 visits to sort it.

Can't remember excactly what it was, definately an electronic sensor, I think on the inlet manifold ,or there abouts. I think it controls the fuel air mixture.

I hope your bloke can fix it but these electronic thingies tend to dealer only jobbies. At least Rover should be used to it by now, having no doubt done a few!!

[swindorski46]

Just checked the cars file, and if I've got the right receipt (as I said it had about six visits), which I think I have, it came down to "reset stepper idle position".

It wasn't under warranty by then either, Cost me 90 sheets, inc vat. That was in 1999, and the car had done 35k.

[phil hill]

This is a relatively common problem, caused by the "idle air control valve", which is indeed operated by a stepper motor. Briefly, the problem is that this stepper motor operates a little air bypass valve which controls idle speed. If the mechanism sticks, becomes unreliable or fails completely the two most common symptoms are stalling, or high (2k~2.5k rpm)idle speed. This should not be a big problem for either a dealer or competent mechanic, but because of it's location underneath the throttle body it can be time-consuming to fix.

[jeffriesmullet]

my lil 98 mini cooper had the same problem i have just sorted it. u dont have 2 take any manifold off and u only have 2 take off 2 screws easy peasy 1st take off air filter box or k&n what ever u have then under neath next 2 clutch master cylinder is a wiring multiplug ontop pf black box with 2 screws either side take off screws and pull out the sensor spray with carb/intake cleaner which u can get at any motor factor for bout £3 spary sum on sensor sum in hole and sum in the actual throttle body wipe of sensor then put sensor back in and screw up job done in bout 15 min for £3 any questions just ask hey i could of just saved u £90 and a trip to rover just give it a go use a haynes manual to find it if u have to but well worth it.