Gday all...
I've got this (electrical i think) problem with the mini... first got the idea that something was wrong at the dyno day we had where my power was down on what i expected, then at the drags my times were down on last visit because it was missing once it was over 6000rpm, also started to notice that the tacho keeps jumping all the time. Then it started getting a bit rough cruising around 3000rpm - missing and stuff. At first i thought it might be the leads, coz some time back they started shorting out where holes had rubbed through the rubber bit on the end of the lead where the cap was pushing against the grille, so i created some more room to stop it happening again and taped up the holes with electrical tape and it ran fine for the next 14 months. Anyway I replaced the leads on Saturday and I thought the problem was solved - ran a bit smoother - but i still feel it giving very slight misses all the time and the tacho needle jumps up about 1000rpm momentarily - the needle barely stays still - always jumping around... and its still not as 'revvy' as it was before so i think the problem is still there...

Suggestions I've had are to replace the igniter unit in the dizzy (its the d4r85 pulsar one) and to try disconnecting the tacho to see if its the cause of the missing. haven't had a chance to try these yet but has anyone else had similar problems or know what would cause it?

thanks

G

When you took off from here Saturday, it sounded ragged momentarily in first . PC reckons igniter still.

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62 Saxon Green 850
Clubby van

I have a similar issue with NAV and i am also running a pulsar dizzy.
Among many things i pulled the wires from the alternator and it stopped jumping around.
It also stops when there is a light on i.e brakes interior. with the alternator hooked up.
I'm gathering my alternator is on its way out (again )
See if this helps you.

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Have you replaced the cap and rotor? My pulsar did this for ages on number 1 until i replaced the lot. About $40 for Bosch ones at Repco for both.

When you buy a pulsar dissy from the wreckers, you don't know what condition it's in so you're best to replace whatever you can...

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Lillee - 1969 Morris Mini K

Yeah he thought there was something on here about a part number for the igniter but i haven't found it yet...

EDIT: just called Rockingham Nissan for a price. They quoted $600 ex-Japan don't think i'll be ordering one of those in...



I know my alternator's not 100%. Its still doing its job (but only just). Maybe thats the reason???



When I bought it, i had it cleaned and regraphed, and the cap is/was new. The rotor is still the original one though. is there any way of visually checking if it has a problem?

G

Sounds like a rectifier in your alternator may not be doing its job....if it is the plug in module type - it could be a very easy fix.

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"Show me the Mini!"

Yes if the rotor is worn it will be visibly worn on the tip. It may also be slack (whobble abit). That said I replaced mine which looks good and it made a diference...

The other thing is, what coil are you running? you should be using a GT40R? and not a GT40?

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Lillee - 1969 Morris Mini K

Home Mechanics 101 - Rule Number 17 - Groups and Pairs - for the best, reliable results. Some things should be replaced from time to time in groups or pairs, for example, a group of ignitions leads or in this case, a dissy cap and rotor.

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"Show me the Mini!"

Another rule..........
When you have a problem only try one thing at a time.

There is no point changing the dizzy and the coil to try to fix a problem because if it works you will not know if it was the dizzy or the coil that was crook!

checked the rotor and its looking a bit off...


I woulda thought though, that if there was a problem with the rotor causing the spark to fail, the tacho might show the revs dropping, not rising???

Don't look three bad...just needs a light going over with some fine emery paper...or a very fine file...you just want to see bright metal on the end facing us, clean up the top behind the vertical face back a couple of mills in from the front and get some steel wool or a scourer on the dimple in the middle of the brass top where the carbon dohickey makes contact....just shine it up.

Ohhhhh and get an Auto Electrician to check the waveform and electrical output of your alternator.

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"Show me the Mini!"

problem solvered...


I ended up buying a new rotor anyway since they're cheap and the old one was a bit worn as well as being grubby. I put the new rotor on, put the cap back in place and started screwing it in. as i turned the screwdriver, the whole dizzy moved and i thought that can't be good so checked and it was loose as anything - the 2 bolts that hold the flange onto the block were loose so i picked a spot randomly and checked the timing and it was maxing out to just under 30* which is where it used to be set - tightened it up and it runs perfectly. now might try some more advance to see if it goes any better...
must remember to check simple/obvious things first...
no wonder it wasn't liking the dyno and drags much with the dizzy wobbling around...

G

Minis can be frustrating like that.....the dissy has one postion (usually) set and forget....but things like this can catch anyone out....you know this one now

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"Show me the Mini!"

So i was right after all! If you didn't replace your rotor you would have not discovered the whobbling dissy

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Lillee - 1969 Morris Mini K

Settle 68...its wobbling

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"Show me the Mini!"