2.25 petrol black deposits on plugs , spluttering exhaust

I knew my series 3(2.25 petrol 1983) wouldnt be a walk in the park but its like having a 2nd full time job! Ok latest problem is this , trouble starting , black dust (not liquid) on plugs which I have cleaned and it has returned and slight black smoke from exhaust when starting just for a few seconds also exhaust splutters slightly as if misfiring , leads look ok , im thinking poss ignition coil. gettinh aspprox 17mpg , drives ok but as its my family full time vehicle cant really afford to be stranded anywhere , oil is black but clear on dipstick and cap

Thanks

If the plugs are that black after a run then carb is set way to rich.Plugs should come out a light brown colour if right,grey to white to lean on the mixture .Check you have the right plugs in and get a tune up. With a correct set up you should get mpg into the low twenty's at least.

Thanks , would this explain the spluttering exhaust and starting problems?

you run a s3 2.25 as your main vehicle? you are brave... or mad

neilcmusic said:

Thanks , would this explain the spluttering exhaust and starting problems?

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or have you checked your choke cable isn't stuck on?

sparks will make a difference when cold. when did you last check the gaps? i'd also give the points+condenser and coil a once over if it's been a while.

even consider the leccy upgrade.

Yes could be a cause of splutter ect and as trax says check choke works right and ignition system is good. Try a plug out of motor in contact with block,spark should be bright and blue, if small and yellow something is not right.

Yes tTrax series 3 as main vehicle! , hopefully brave not mad , insurance on previous car was £498 , landy is only £175 so hopefully it will balance out as landy as you know is very thirsty. Kids love it and I live within walking distance of work , so far all good , Ive had a few issues but so far ive had it 3 weeks and only spent £30 on it so hopefully all will be good.

Good thing is parts prices for landys are low compared to other makes and many jobs easy to do oneself with basic tools and workshop manual,also lot's of help to be had here in landyzone.
Do let us know how you get on with your bus. cheers.

A well tuned land rover will still get a bit of black on the plugs from starting on the choke. It should burn off to a nice coffee colour on the porcelain. But only when the engine is run for a while at full chat it will probably soot up straight away on idle though. If you want to use the colour of plugs as a tuning aid you have to cut the engine and coast to a stop to see what colour they are when they are actually doing what they do.

A bit of soot is not usually a sign for real concern. 17mpg is probably about right unless you spend a bit of time tuning up.

A colourtune is a good place to start when setting up your carb unless you want to spend a lot of money on Lambda sensors or gas analysers.

What Carburettor do you have? A Weber 34ICH might get you a few more MPG, a 32/34DMTL will get you a bit more but then you're into swapping manifolds and custom exhausts. An ACR or Turner 9:1 head or a head skim will get you more and will allow the use of unleaded petrol.

I regularly get 19-21mpg on the very steep hills round here and 26mpg+ at 60 on the motorway. But that's with 3.54 diffs, an overdrive an ACR head and cam and DMTL carb....a lot of investment. If you just want to save money then a gas conversion might be the way to go though I personally don't like them.

If its driving well, without spending a lot of time and effort you're probably doing better than most.

You do have to remember that you're more or less driving a 1930's gearbox mated to a 1950's engine pushing something with worse aerodynamics than a brick tied to a parachute so you're never going to get super efficient...

ok cleaned plugs again , altered mixture screw on carb and they now have slight brown dust on them after a long run which im happy with. Only major concern (lots of minors) I have now its the fact that it often doesnt start , will probably buy electric ignition , cheap enough and I hear good things about them.

neilcmusic said:

ok cleaned plugs again , altered mixture screw on carb and they now have slight brown dust on them after a long run which im happy with. Only major concern (lots of minors) I have now its the fact that it often doesnt start , will probably buy electric ignition , cheap enough and I hear good things about them.

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do a new coil and ht leads at the same time.

done my mates and although it's only been on less than a year old it starts on the button.

Is it starting that's an issue or cold running - i.e. once it fires is it ok.

How are you working with the choke - I find it tricky to guage how much choke to give on cold days. Too little and it will not fire at all or die straight away. Too much and it will flood and take ages to get going!

I find the best plan is to turn it over with little or no choke until it catches then pull choke out slowly until it starts to rev keep going until it starts to run rough and push back in. Then give it a bit of throttle to blow out excess fuel. Then push choke back in a bit.

Other reasons for difficult starting which is worth a check:
- fuel draining back into tank. If your fuel line has a small leak then it will take a lot of turns of the engine to fill the carb bowl up. If you have an inline filter see if it has fuel in it, it needn't be completely full.
- poor coil / points / leads / plugs - these will make it run rough when damp more than just starting - electronic points can help but are not a cure-all.
- flooding - if it's being a ***T to start try taking a plug out and see if its **** wet through with petrol - if it is you're giving it too much choke, if it's completely dry too little
- poor battery - slow turn over will not help. A petrol with a good battery should turn over at a good pace even on a cold day.
- ignition advance - over advanced ignition will not help cold starts, knocking it back in winter can help though it may adversely affect performance. A bit of time tuning the springs in the dissy can help but its a bit of a black art. If it sounds to be catching but when it catches the starter goes slower then retarding the ignition will help - though again a strong battery should be tried first.
- choke - check its actually working properly - pull top pipe off the carb - with someone else operating the choke the top butterfly should open/close smoothly and it should be possible to open the butterfly easily by pressing it with your finger very lightly. A bit of lubrication around the cable and butterfly is often in order