Morris Minor Owners Club

while we got this engine running very nicely for 30 mins then it decided to die slowly like it wasnt geting fuel, its coming out of the pump and there is a spark but after crankin for a bit they are still dry

should i take my carb apart and see if something is blocking the way

cheers tom

Just pour some fuel down the carb - if it runs then indeed there must be a blockage (MOST unusual) - otherwise - look at the ignition.

forgot to put we took the air filter off and sprayed carb cleaner down, there is a very stong blue spark at the plugs

And - did it run ok on the carb cleaner ?

no nothing would get it started, wornt fire at all

Well - if it won't start on spray - or fuel down the carb - then the problem is with the ignition. Assuming the engine is ok mechanically - ie the pistons are going up and down and the valves are opening and closing..........

yes everything is moving freely, but what i dont get is all the plugs have a strong spark and it was running fine so which bit would i check ?

Can only be the timing of the spark in relation to the piston - mystery I know since you say it was running - but maybe the dizzy is loose -something like that ?

I had a similar problem last week. I fitted an old distributor to my Series MM which soon after started misfiring, gradually getting worse until it was vertually undriveable. It would run perfectly on tickover but died as soon as the engine was under load. I eventually made it back home and changed the distributor top plate which cured the problem. As the points were set correctly it must have been the condenser.

Hotrodder,

When the fault isn't obvious you're forced to seek the unusual. If you've fuel getting to the carb and squirting fuel down the intake gives no response then I suspect the ignition system. If the timing hasn't shifted (most unlikely) and with good sparks seen on exposed plugs then I suggest its sparks failing under compression. And for a complete and rapid engine cut out rather than long drawn out stuttering failure I'd suspect the distributor rather than the igntiom leads.

After a change of condensor and a check of the gap, I suggest you look closely (i.e. with a magnifying glass) at the interior of the distributor cap for cracks and tracking marks where your precious sparks might have leaked away. Even if you can't see any but a good clean inside and out gives you a start then I'd still suspect a crack. If so, "Damp Start" will give you a temporary cure but a new cap would be the answer. (And cost about £1-2 at an auto-jumble.)

And when you get the start, try to view the igntion system in the dark - its surprising the amount of sparking/corona discharge/lightning that can be there even on a perfectly functioning system - before the failures start!

Regards, MikeN.

the dizzy and cap have only done about 200 miles since brand new, its electronic and the way it died was it was running fine then the idle slowed down and changed note and finally dstripped and cleaned the carb and the spark plug ends are now getting wet, the time was done staticly and there is still a very stong blue spark

should i do a compression test ?

cheers tom

Oh dear! I think you should put on your asbestos suit before Roy arrives with his "I hate electrnic ignition systems" lecture!
MikeN.

i know, i dont think he hates them just prefers points and condensor

Hotrodder,
I doubt that poor compression will be the cause. Firstly it tends to decline unevenly across the cylinders so some keep doing well and helping to give a good start and secondly it declines slowly causing a loss of power that's obvious, often accompanied by rough running and a poor tickover that you have to richen up to offset. None this seems to match your symptoms.

I still suspect the sparks. There used to be a test in which you widened the plug gap to require a higher voltage to give a good spark, the idea being that this voltage would match that required under compression in the cylinder. There was a little tool, a variable gap device wtih, I recall, a scale of the assumed voltages involved. Perhaps an old codger will be along soon who might give the appropriate gap for a test. I've seen it somewhere here - I'll keep looking.

Regards, MikeN.

Did you get the updated rotor arm to go with the other bits?

The newer standard ones aren't even good enough for standard sparks.

it does have a powermax rotor arm, think im guna take it to the garage, first job im sick of

Before you do, read this (I hope this link works)

http://books.google.co.uk/books?id=VCcD ... &q&f=false

A homemade gap spark tester is described here in which they say the spark should jump about 10mm in open air in a good system. Looking elsewhere on the web this seems to indicate about 30kv being available, enough to spark under compression.

Finally dare I say perhaps you should re-fit the old contact breaker system as a check on the electronics?

The best of luck, MikeN.

yes it works , but i do not have the old one as it broke

we are going to clean the plugs again and try again 2moro and if it dosnt work its getting sent to the garage (getting too cold for me and i work in it all day which dosnt help)

I can't imagine what the 'garage' are going to do - or charge you! Sure it didn't just flood up? Try another set of plugs - and NOT NGKs. This is pretty much the problem my mate had with his non starting MGB - after I had been fiddling with it for ages he eventually 'let on' that he had fitted new NGK plugs........ I pulled them out - stuck in an old set of Champions I had in my bag - and it started straight away. The NGKs are now somewhere in the field behind his house ....... to prevent him being tempted to put them back in!!

Garage wornt charge me ewt as i know him , the engine came with ngk but took them out for my champion ones