9 replies to this topic

[mattso118]

hi everyone,

my 1987 mini mayfair 998 is running like a dog, basically the engine cut out the other day and when it restarted it was chugging and the engine sounded as though it was ticking, when i checked the plugs and leads only the two left hand plugs were sparking, the leads are in the right firing order, all the plugs are working as are the leads, so what could be causing the car to run on two cylinders? It was suggested by a friend that it could be the headgasket thats blown, if so what exactly am i looking for?
Thanks

[Pauly]

First I would check your plug gaps, then check your HT leads, even if they are new they may have been caught on something and have a split in them, then check your rocker clearences. Failing all that, do a compression test.

[mattso118]

gaps are good, i know its not the leads because if i swap the leads of the two that are working with the two that arent it changes nothing, so compression test is next step, what should i be expecting for each ?
Thanks

[Turbo Nick]

check the manifold gasket first, spray with carb/brake cleaner and see if the revs pick up.

[mattso118]

check the manifold gasket first, spray with carb/brake cleaner and see if the revs pick up.

ok will do that tomorrow as i have day off work, would a problem with manifold gasket affect only two of the cylinders and prevent the plugs from doing there job?

[Jordie]

dont worry about the figure on the compression test as such, aslong as they are all somewhere near. +/- 10 say.

[Turbo Nick]

check the manifold gasket first, spray with carb/brake cleaner and see if the revs pick up.

ok will do that tomorrow as i have day off work, would a problem with manifold gasket affect only two of the cylinders and prevent the plugs from doing there job?

yes, if it's blown then it'd suck in air after the carb and be too lean to burn.

[Cooperman]

To go back to your original post, you said that only the two plugs were sparking, but then you said that all the plugs are working. Now, which is it? If only 2 plugs are sparking, then it's either two damaged leads or a cracked distributor cap. If all plugs are sparking, then it's something else, not ignition related, such as head gasket, manifold leak or valves/compression issues.

[mattso118]

To go back to your original post, you said that only the two plugs were sparking, but then you said that all the plugs are working. Now, which is it? If only 2 plugs are sparking, then it's either two damaged leads or a cracked distributor cap. If all plugs are sparking, then it's something else, not ignition related, such as head gasket, manifold leak or valves/compression issues.

sorry should have made my post a bit clearer, if i change the two left hand plugs with the two right hand plugs (which dont spark) the engine still runs on he two left hand cylinders likewise the leads, all the plugs and leads work correctly in the two left hand cylinders but not in the two right hand cylinders if that makes sense? All four of the leads can be heard to spark when not connected to the spark plugs, so guess that should rule out distributer cap,

[Cooperman]

It's easiest to whip the head off and check/change the HG. A nice job for a Saturday morning.