Hey guys/girls, Im having trouble again with the "2000km car". (it runs great for 2000ks then breaks down for 6 months). Its an 88 Rover mini, with a 1275spi manual drivetrain. Its always had a bit of a flat spot at about 2000rpm. This was partially rectified 2 years ago by a new throttle body. It ran like a dream all the way from melb-yass-goulburn-melb for the mini 50th, but then started playing up. Taking off from the lights, if you don't hold your tongue right, it pops and sounds like its running on 3 cylinders, bucks, backfires and blows lots of black smoke. However if you keep the revs above 2500 (from start) its great! Ive searched on here and the mini uk forums and changed the vacuum lines (mine were a bit ordinary) replaced the fuel trap (once again very greasy), removed the ecu, stuffed the map sensor with cotton, kept it over a radiator overnight to draw out oil and fuel vapour (which it did nicely), removed the timing sensor below the starter motor (very dirty) cleaned it all up nicely and put it all back together. Still it coughs and carrys on. The weird thing is, I drove it around a week ago for 30 mins "playing" up in the dandenongs and it didn't miss a beat, today, started beautifully, drove down my street, all going well, turned on the main road and it sounded like a spark plug died or something as i was back to what felt like 3 cylinders and smoking the street out. Its very intermittent. I've replaced the spark plugs, air cleaner (was about 5000kms since last change anyway) but still I can't get it right. Any ideas from what else I can try? Only things I can think of left are oxygen sensor (but wouldn't that just stop, not be occasionally working?) and fuel filter. Any input greatly appreciated.
Thanks
Josh

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88 Rover 1.3i "Reggie"
99 Rover 1.3i “Grover”
12 Mini Cooper S "The shitter"
17 Mini Clubman JCW “Noddy”

Have you tried new leads? That sounds like an easy thing to try.

Harder one to fault find would be throttle position sensor.

The vacuum lines are an easy source for a leak and to fix, but remember there are two engine breathers that also go to the throttle body. The one by the fan is prone to leaking because it gets hot down there.

Asan experiment, disconnect the purge valve and take the car for a drive and then reconnect it later and see if theres a change. Its possible that fuel vapour or a leaky line there may be doing something.

if they have a crank angle sensor not sure on them they play up when they get hot id be changing that first if they have one,


cheers dan

A few ideas here on crank angle sensor. I had one go in a subaru once and it was hard to start , ran like a dog at low revs. Also try another coil. I had one on my 7 port that would miss between 3000 - 3500 rpm only.
Cheers.


http://www.tmsmini.com/cooper/sp_acr.htm

http://www.theminiforum.co.uk/forums/lo ... 30014.html
Quote from the mini forum below:
"could be conection look at them good clean them if oily and clean the coil as well. see if that helps if not change the coil for one you know that works if no joy then the sensor may well be duff


Had the same problem recently on my '95 Spi cooper - turned out to be the crank sensor connections were corroded. Gave them a good clean up (both in the plug and the socket - you can unbolt the one attached to the engine for better access) cleaned them up with fine sandpaper. Sorted.

My car actually went from running, to not starting at all (for a day) to starting and running but spluttering everywhere, then when I came home with a meter, scope etc from work, seemed to be fine (typical). then later that day it happenned again - so while it was doing it, I waggled the connector for the crank sensor and it stopped doing it - good sign!

Also, if it is the crank sensor signal dropping out, then each time it happens the fuel pump and main relay in the black relay box, will switch off . So you could put your ear to the box and listen for the clicking of relays which are going on and off as a further clue. On mine, I can remove the cover of the relay module due to a previous repair, so I can see the relays operating.

But easiest check, waggle the crank sensor connector when its happening.

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Now with 2 extra ports!

Thanks for all your help guys, Have been a bit busy over the long weekend but will try the simple things first. This week i'll swap ht leads from car that is running fine and check breather hoses and crank sensor connections. 3 obvious things I didn't think of. Cheers fellas!

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88 Rover 1.3i "Reggie"
99 Rover 1.3i “Grover”
12 Mini Cooper S "The shitter"
17 Mini Clubman JCW “Noddy”

with holdens if they play up sometimes pouring water over them when there running up the crap will make them come good for a moment. then you can confirm the crankangle sensor is internal problem when hot.

Cheers dan

I think boyracer (no longer on here as he sold his Rover) had the same sort of issue, chased it all around the houses all sorts of things and it turned out to be the Crank Angle Sensor.

+1 for CAS

Having had a few of these myself, i have another suggestion, will post it when I get home later tonight,

try the fuel inertia cut off switch, that could be on its way out..



if you can get another one swap it and try that..

otherwise sometimes it can just be the computer, somtimes it will get an error and just need to be reset..

you wouldn't replace it, just throw it in the nearest bin.

If you bin the inertia switch then the pump won't work unless the plug is bridged again.
I wouldn't recommend it, its there as a safety feature.

yep bridge it. it is a shitfull safety feature. all it does is shuts the pump of in the event of a rollover or if you hit the curbs at mallala it will shut it down too. or just drive over a decent railway crossing.
if it's on it's roof it stalls anyway and the pump stops same same.

It's designed to cut out in a crash too I believe.

you are right, so what turn's off a carby mini if you are in an accident? oh no we are all going to die aaaaggghhhhhhh.