1984 Mini Mayfair Auto - stalling

[billb]

Hi.


My wife's oldest automatic Mini - a 1984 Mini Mayfair - has just started stalling each time you roll to a stand-still. Whether going forward or in reverse as you slow down to stop the engine revs drop down to the point where it stalls. It restarts immediately and ticks over happily.

I have checked over the carb (fairly new) and the dissy (new points, reset and double checked), timing, plugs etc. Everything checks out fine. It is now in the garage of a friend who has been looking at for me in-between doing his routine vehicle servicing and repair. He can't find anything wrong with the engine side of things either. We both think that it must be the auto box. It's like it doesn't want to disengage the drive and so, as the wheels slow to a stop so does the engine.

Anyone any ideas please??

Cheers,

Bill

[miniman35]

Hi Bill, my 1980 city has started doing the same thing this week. But sometimes the engine will not turn over after the install. I had started to suspect that the engine couldn't detect that it was in the natural. Then I noticed that right side indicator remains on even if I turned it off. I've not had the time to start trouble shooting the issue but I guess the loom in my case is damaged near the front. The reason I think this, I but the damp guard back it and it's rubbing against the loom. Not by me but someone modified the loom. I will try in the next few days to look into the issue and let you know how I get on.

[puddingmobile]

If it's anything in the gearbox, it would have to be in the torque convertor, as that is effectively your "clutch". If the T/C is starting to seize, it will feel like the car is still trying to pull as you come to a stop and you will likely notice increased braking effort. Otherwise it may just be a tuning issue. Hope that helps.

[notamini]

Are you sure your timing is correct? I was told 10 degrees @ 1000 rpm. Are you using the correct oil in your carburetor damper?

[notamini]

The book says idle speed 650 rpm. Fast idle 1050 rpm. Timing 10 deg @ 600 rpm.

[billb]

Thanks for responses Good People!


Positive that it's not a timing / tuning issue. I double-checked everything possible - and got my much more knowledgeable friend (professional running his own garage) to do the same. I have lost confidence in my ability over this and was mightily relieved when he said that any adjusting was a "nats" only. He can't find anything wrong with the engine set up. Starts like a dream, revs and ticks over really happily. Put it into Drive or Reverse, revs drop as normal and all is well, slowly (or quickly) pull away and all is well. Come to a stand still and the revs drop as the wheels slow until it stalls. Probably going to speak to www.theautomaticgearboxcompany.co.uk/ 

[jockduck]

Sounds a bit weird, My mini I notice that the car "drifts" as it changes down from second down to first. The one way sprag on 1st effectively lets the car freewheel until the car stops and first then engages and the revs drop. I don't know if that helps. One question have you tried a stall test? With the engine running I suggest selecting 2nd manually with the foot brake firmly applied push the accelerator and note what revs the engine gets up to, its different for different capacities somewhere around 1300 rpm. The workshop manuals give speeds and possible faults.
Jock

[firept]

We are assuming that the oil level is correct and the correct grade of MA2 oil is in use.

Next question I was always taught to ask when fault finding so what has changed or what has been done, added to, no matter how simple or irrelevant it may seem.

What happens if you drive the car 'manually' do you still have the same problem?

From my limited knowledge the difference is that the governor is not in use when in manual it therefore eliminates the governor and its associated pipes and downshift linkage from carb to gearbox also have you checked that the linkage to the gear box selector shaft is correctly adjusted as you may have a slight misalignment in the selector rod to cable this is quite critical the proper BL manual has all the details, shout if you are stuck as I could provide a copy of the details.
After this I would next do a pressure test and see whats happening.
hope this may help
Paul.

[wimfournier]

I think you over filled the engine oil.
Do you follow the precise instructions for reading the dipstick?
Namely;
after you have driven the car for quite a time so that the engine is at 'working temperature', you switch it off and wait five minutes. Than you pull the dipstick, dry it off and put it back and pull it again. The reading of the surface of the oil has to be between the two lines that mark low and full.
Point is, that when the car stands a few hours and is cooled down to ambient temperature, about a litre oil has drained out of the torque converter into the sump. The reading of the dipstick will be 'good' or 'high'.
On the other hand, when you read the dipstick immediately after you drove the car for quite a while, the torque converter is filled with oil. That oil came from the sump. When you read the dipstick, it will be low or almost low. When you add at that moment a litre engine oil to get the dipstick reading op to 'full' you have one litre engine oil too much in the sump and the torque converter has trouble to get rid of the oil that it should spill. This is resulting in too much 'grip' in the converter to let loose the propelling of the gearbox. It doesn't come to freewheeling.
So; give it a try with one litre less oil in the sump, maybe the problem is solved.

[miniman35]

Hi, I finally got to look at mine yesterday. I found 3 issue with electrics.

1: the reverse switch was sticking, cleaned that.

2: the inhibitor switch was rusted at the back and one of the wires was loose. I wasn't able to repair it as there wasn't enough good connection to soldier the wire onto. So for the moment I bypassed the switch.

3: I then noticed that my solenoid was loose, when I fixed that I noticed some of the wiring wasn't fully seated. When I fixed this, the engine turned over (even sounded better).

Thanks

[notamini]

Don't forget to tell your mechanical friend. Wink, Wink

[notamini]

What we need to understand with these automatic transmissions is the number of situations and conditions which can affect the performance. This past week, i removed the carb and reset the jet to .090" down or 12 flats. Mine was .115" down. I reset my low and fast idles and my choke cable. Then I went in and reset my timing[quite confusing info in my 4 manuals. Two said 10deg @ 650rpm and two said 3deg @ 1000rpm with vacuum removed]as it turns out, they are both right. I had it at 10deg @ 1000rpm.
After all this work:
When I placed the shift into Reverse, it went in real smooth. When I shifted it into 1st, it went smooth again. At this point, I hadn't applied the accelerator. When I did push it the pickup shocked me! Beautiful. Gears shift awesome. And for once the car sat and behaved itself in gear at a full stop. there was no oil light or rough idle.
Once the start inhibitor switch is fixed, (it's coming apart from its housing) He'll be ready for my 350 mile trip on June 15. BTW, he turns 50 yrs old on June 12th.
Cheers,
Mark

[wimfournier]

Perfect!
Now I wonder how far 'billb' has come with his troubles.

[notamini]

I'd like to hear from him too. How are you getting along, Bill?

[billb]

Hi Good People (and friends!).


I am sorry not to have responded before but we were called away as my Dad was unwell. After a long visit with him he sadly passed away - and we have only just started to get things back to normal.


Whilst we were away I left the Mini with my garage-owning friend and he tried everything he could think of to fix it in-between his normal work and had arrived at my conclusion - that there was something odd about the gearbox.


Yesterday I went to get it with a view to driving it slowly home and speaking to www.theautomaticgearboxcompany.co.uk. When I got there he was all smiles - he thinks he has fixed it! I drove it home happily and used it yesterday for a 20 mile trip with no problems or issues at all. He said that in desperation he had put his timing light away and had just slowly rotated the distributor to advance the ignition / drove it / turned it …. until he got to the point where it runs like a bird!!! I checked it with my light (with the advance tube still attached) and it is set to 20 degrees BTDC. I'll have a bit of a play and check with the tube unattached - but the gearbox appears to be blameless!!!


I thank you all for your advice and comments. I'll keep you informed.


Take care all, and thanks again!