25 replies to this topic

[chris2009]

998cc Mayfair:
1986:
As i was driving home a couple of nights a go my mini had a really bad lack in power and couldnt get it past 2nd gear it sounded as if it was not firing on all cylinders and there was alot louder on one of the cylinders. I tired starting it the next morning was very slow starting up, kind of chugged itself into life. When it started the only way to keep it running was with a little bit of throttle. I first thought it maybe a contact on the dizzy. So i took the cap off emery clothed each contact down. Still no improvement with running. Thought it may have been something more serious as in head gasket gone but no mayonaisey type substances on oil cap. It had new plugs about 5 months ago. Any ideas really need to get back on the road asap.



water heated mani with straighthrough pipe

[Lukie-J]

I had a similar problem with my 998. Was running on 3 cylinders. Have you checked the points gap and the timing?
That's what sorted mine out.

[chris2009]

No i haven't how would you go about doing that?

Ive had probalems with my dizzy already the rotor arm somehow snapped inside the cap. This may have caused a bit of damage to the inside. One of the contacts on the cap looked a bit corroded would this also contribute?

[Lukie-J]

The corrosion may contribute to it.
Another thing to check is the plug leads (HT leads)
To do this:
Start the engine,
Pull the lead off of the spark plug whilst the engine is still running
Listen to the engine and if you hear a drop in revs then you know that lead is OK.
Replace lead and check next lead, and so on.
If there is no change to how the car is running then this is the cylinder that isn't firing.
Try a new lead on it and see if that helps.

Also, once you know which cylinder isn't firing you could look inside the distributor cap and see if the contact for that lead is the one that is corroded.

Then look at setting the points/timing.
(I can't quite remember how to do it, I would know if I was actually doing it!! Sorry)

[chris2009]

Brilliant cheers buddy i'll try that in the morning it waaay too dark to start anythying now. Will give an update tomorrow on how things go. cheers for the help

[bmcecosse]

Almost certainly the head gasket - get a compression check. It 'may' just be a burned exhaust valve - but i doubt it.

[Pauly]

Almost certainly the head gasket - get a compression check. It 'may' just be a burned exhaust valve - but i doubt it.

Woah hold a bit. I agree to some extent but you've got to do the basics first before ripping it to bits.

Do the basics first. Check your HT leads as already said, pull one off at a time and see if the engine note changes when you pull one off and the note doesn't change then thats the faulty cylinder. Hover the lead over the spark plug (use gloves!) and hear if its sparking, if not the lead has gone.

Check your plug gaps and condition of them (wouldn't make much difference).

Dizzy caps not cracked?

And failing all that then its the head gasket, do a compression test before hand though to confirm it.

Paul.

[bmcecosse]

Which is why I suggest a comp check! An engine suddenly as poorly as this - it will be the gasket.

[chris2009]

I thought it might have been the head gasket aswell but there's no mayonaisey type substances on the oil filler and i had to drive it quite a way just to get it home and ive run it two or three times after and still nothing. Im hopefully going to get a new dizzy cap somewhere today but i cant find any places that are open near by. Any one got any ideas of parts shops near shoreham by sea, worthing area?

[lrostoke]

Halfords should sell them you got one near.

[minigal]

i had this on my car, it was running great untill it suddenly started to really struggle with power. i started it up in the morning and it took ages! i did a compression test to find cylinders 1 and 2 had nothing. so i took the head off to find the head gasket had gone between these cylinders, so they were just passing air between them!

Edited by minigal, 30 December 2009 - 02:04 PM.

[BoboGib]

I thought it might have been the head gasket aswell but there's no mayonaisey type substances on the oil filler and i had to drive it quite a way just to get it home and ive run it two or three times after and still nothing. Im hopefully going to get a new dizzy cap somewhere today but i cant find any places that are open near by. Any one got any ideas of parts shops near shoreham by sea, worthing area?

You don't always get mayonaise on the filler with a head gasket failure. It can go in several ways.

It can go between an oil gallery and the bore meaning you will get lots of blue smoke and lose oil
It can go between a water gallery and the bore meaning you will lose water, over heat and the exhaust will steam and water will come out (very hard to see over normal exhaust condensation)

It can go between an oil gallery and water gallery meanin the oil and water willo mix and you will get the mayonaise on either the filler cap, in the radiator/expansion tank or even on the dip stick, again it will over heat.

It can go between 2 cylinder bores meaning you will lose compression and it will run like a bag of nails. In this case you need to do a compression test to diagnose it. It will be obvious to tell if there is a fault when you test it.


As also suggested check all your ignition components, plug gaps, leads, make sure the cap isn't cracked.

[chris2009]

Yeah but classic halfords are out of stock cant get any parts till tuesday.

[BoboGib]

either of these close to you?

Edited by BoboGib, 30 December 2009 - 02:20 PM.

[chris2009]

Ok I have a feelling it maybe the head gasket now which is an absolute bugger seeing as i have none of the tools of space at home to replace it. Plus being a student working one day a week I have nowhere near the amount of money it is to get a garage to do it. Any ideas on places that are close by, as she cant exactly move far, and not through the roof prices.