spark plug wires help

my series 3 isnt firing in one (possible two, but not likely) cylinder, i recently replaced the spark plugs, but should i replace the spark plug wires aswell? they have some new looking ones already on that they came with, except the wire going to the fourth cylinder is different to the others, and looks older. if i should replace them what ones should i get? and whats the wiring order coming from the distributor which i think is an old style lucas 25D4? any help at all would be appreciated, thanks!

Check the plug leads work by putting the plug lead lights on if you know them, then you will know what is firing. Take out each spark plug and make sure it is clean, not damaged and a small distance from the plug and pin. Fit them again..being sure not to crossthread them. Then take off the dizzy cap (Distributor cap) making sure you can see the firing pins are ther and not damaged, that the area is clean and dry and to make sure each lead is connecting properly. Usually your problems lie in that area so have a look

i bort a set of 4 plug testers from halfrauds fer £8... best £8 i spent

nathan5346 said:

i bort a set of 4 plug testers from halfrauds fer £8... best £8 i spent

Click to expand...

They show that you have spark but not the strength of it. I use a single adustable spark tester. It'll show a weak spark when the light up ones show a good spark.

6PC IGNITION SPARK PLUG HT LEAD DIAGNOSTIC TESTER KIT on eBay (end time 09-Jan-10 01:39:59 GMT)

The bottom one of the 3 is what I use.

Even if you've done just the plugs, change the HT leads as well. As you've got a running issue, change the HT leads.

As for brand, it doesn't matter too much. Don't spend too much money on something like that for a Series. Some Lucas wires should be fine.

Was there a misfire evident before changing the plugs, or did this occur after fitting them?

yes, the problem was there before the change of spark plugs, but i think its obvious it isnt firing on one cylinder and all the new spark plugs did was make the other cylinders run a bit better, it still cuts out of you floor the accelerator.

Well I suppose as it is an unknown in terms of service and maintenance, that you probably should replace the HT leads and also service the distributor as well. Do you know what bits you need to service the ignition system?

no idea, the points set definately work, i took the cap off and turned it over, they sparked well. i've got no idea of the condition of everything else in there, im not that knowledgable. the HT leads could be in the wrong order, but then why would only 1 not fire?

wedmore somerset?

could be, but no, i live in east sussex, on a small farm near the town hastings.

check all the basics - take the plugs out and check the gaps, are they all the same colour?
try changing a pair of plugs and see if the problem moves. try swapping a couple of leads over (ones that both reach) and see if it changes.

fanatic said:

wedmore somerset?

Click to expand...

Boston dawsons?

After running into Amy at a movie theatre in Boston, Dawson's spends the night at Amy's house and the two make love.
:doh:

fanatic said:

After running into Amy at a movie theatre in Boston, Dawson's spends the night at Amy's house and the two make love.
:doh:

Click to expand...

pillock

Oz Wedmore said:

yes, the problem was there before the change of spark plugs, but i think its obvious it isnt firing on one cylinder and all the new spark plugs did was make the other cylinders run a bit better, it still cuts out of you floor the accelerator.

Click to expand...

That suggests a CARBURETTOR problem more than plugs and wires.

Do the HT leads and the King lead anyway, and then make sure the "Accelerator Pump" doo-dah on the carb is working properly, AND that the fuel level is right on the float chamber, AND that it isn't full of crap that has blocked the jets.

The engine may 'backfire' into the carb for these reasons.

In other words, take the carb off, and clean it really well. Loads of threads here about this.


CharlesY

Perhaps I am being a bit too much back to basics here...but first thing I would do is take the plugs out and see which ones are actually sparking. If one (or maybe two as you say) are not sparking then swap the good leads for the crap ones and see if the problem is swapped to the other plugs. If it does change leads are quite clearly the problem. If not, then persist with something else.

Is the distributor cap in good order? Changed that recently?

Could be a problem with the points...take the distributor cap off (turn ignition off) and turn the engine over by hand - make sure the points are opening and the gap is as expected. This very weekend I had a problem with mine in that it was only firing on cylinders 2 and 4 - very odd. In the end found that the shaft of the distributor was bent so instead of going round as it should, was working almost like a cam. Poor old thing - don't ask how it got like that!

If you are getting a good spark on all plugs then ignition is probably not the problem - I would suggest doing a compression test or as Charles says, check your carb and fuelling.

wiring order coming from the distributor which i think is an old style lucas

Click to expand...

As far as I know, all Series Land Rovers are 1,3,4 2 (which might also be stamped on your manifold or rocker cover). Number one on the distributor is the closest to the radiator, and work anti-clockwise.

i had much the same prob a month or so ago after loads of messing around and getting frustrated i changed every thing plugs,leads,dizzy cap and points problem solved and it does not cost a fortune why not change the oil and filter while your at it good luck

rustyrhinos said:

As far as I know, all Series Land Rovers are 1,3,4 2 (which might also be stamped on your manifold or rocker cover). Number one on the distributor is the closest to the radiator, and work anti-clockwise.

Click to expand...

FOUR cylinder in-line engines are ALWAYS 1-2-4-3 (as in Fords and silly-arse cars like them) or 1-3-4-2 as in decent Imperial BRITISH cars like Landrovers.

They are the same thing but the other way round, and the firing order is determined by the camshaft.

In-Line SIX cylinder engines are almost invariably 1-5-3-6-2-4
because they are really two 3-cylinder engines end to end, firing in opposite orders
1-3-2-1-3-2-1-3-2-1 for the first three, So 3-2-1 order
and
5-6-4-5-6-4-5-6-4-5-6-4 , so 4-5-6 order
spaced alternately with the first three.

Sorry about that. I hope someone found it useful.

CharlesY

ere CharlesY - yu is long int toof - wot about EnFo?

The Mad Hat Man said:

ere CharlesY - yu is long int toof - wot about EnFo?

Click to expand...

EnFo and MoWoG, and Rootes ?

and BL

the good old days when Brits made lousy rusty cars which we all bought.

But EnFo (EnglandFord) used the other way for a firing order for some reason. It was probably to do with their Merkin background - backwards more like.

And yes, I am long in the toof. Passed my first driving test in 1959 on a 50cc Victoria moped, which I gave away that same day, the day I set off on my 500cc Triumph GP Special motorbike!