Morris Minor Owners Club

Sorry, I know this is a Morris forum and this question doesnt relate to Minors at all, but what with Morris owners generally being a wealth of auto-mechanical info I thought there might be someone who could shed some light on this.

I have borrowed a Diesel Punto while I'm stripping my 2-door for painting, that when in regular use gives me no trouble whatsoever, however when I park it up for a few days and come back to it, it has serious trouble starting.

The battery doesnt seem flat as it turns over nicely, but it really does struggle to start and when it finally does, it coughs and splutters with clouds of white smoke (unburnt fuel I assume, since it goes away very quickly).

Could this just be that the glow plugs need replacing, or could it be some kind of compression issue?

I dont really know much about Diesel engines as most of my cars have always been A-Series based (minis & minors), and the haynes manual only seems to cover replacing the wiper blades & changing the oil filter!!!

So any light you can shed, or pointers in the right direction for me to learn more would be most useful.

Thanks, Alain.

My first guess would be glow plugs too - it could also be the relay that turns them on. I presume you wait until the glowplug light turns off?

I presume you wait until the glowplug light turns off?

Sometimes twice!! ... your relay idea sounds like it has some merit, I'll go have a shuftie and see if anything looks corroded/burnt

Most likely the glow plugs. Peugot engines are also known for failing early and having similar symptoms. It could also be a head gasket though. I had a diesel that struggled to start and let out white steam, even though the plugs were fine. The clue was that the first revolution on cranking was very slow, but then OK. That was the water in the cylinder!

White smoke on start up usually indicates water in the cylinders due to a leaking head gasket.

To test a glow plug take one out and connect 12 volts across its terminals. The easiest way is to use a jump lead to connect one battery terminal to the body of the glow plug and then press the top of the glow plug onto the other battery terminal.

If they are working correctly they should draw a high current as they have a very low resistance and the tip should glow red hot.

The glow plugs on my Peugot 405 TD recently failed after 95000 miles.

A new set cost about £20ish from my local motor factors.

I'm sure a lot of people out there would twell you this is normal behaviour for a Fiat but don't believe a word of it. We had a 60bhp '99 plate Turbo Diesel Punto which was a peach and ran very well. 50mpg on a run and no rough running whatsoever.
I would also think you are getting water in somehow. maybe through a cylinder head problem that causes a gap when the engine is cold.

Yeah, I was worried it might be the head-gasket, I'll try your tip about testing the glow-plugs and see what that gives me.

How would i go about testing the compression on a diesel? (pull the glow plugs and treat it like a petrol engine?)

Will a 'normal' compression tester be ok (ie the one I use for my A-Series) or do diesels need a special one? (given that I guess they run at much higher compression ratios)

alainmoran wrote: How would i go about testing the compression on a diesel? (pull the glow plugs and treat it like a petrol engine?)

Diesels aren't my thing, but I think pulling the glowplugs to test might not be a good idea! I'm basing that on the fact they're a compression engine, so may still fire up as soon as fuel hits the cylinders and gets squashed.

Maybe pulling the injectors to get the tester in would work though?

if u turn the key straight away without watingi for the light to go out and not give the glowpugs time to warm up, then if it is just as rough to start then the glowplugs arent working anyway i think?? if its even harder to start then they must be doing soemthing.

f u turn the key straight away without watingi for the light to go out and not give the glowpugs time to warm up, then if it is just as rough to start then the glowplugs arent working anyway i think?? if its even harder to start then they must be doing soemthing.

Not if only some are working. It would be like starting a petrol engine with only 2 spark plugs working.