Rough Running

Hi,
Looking for a bit of advise / pointers , I have a series 3 , with a N/A 2.5 petrol fitted , got in this morning and overnight it seems to have developed a rough running , spluttering & occasionally back firing , with an associated lack of power, particularly in the lower gears . When I get into 4th and get some steam up , it seems to disappear , Just to return when I slow and drop into lower gears. Any one experienced similar ? or have any thoughts on the first things I should be looking at ?
Much appreciated
Steve

There's a lot of things it could be, its most likely an ignition problem but could be fuel.

Ignition - check this first:
- before pulling the warm the car up then leave it idling for 5 mins
- plugs, when did you last change them? Take them out take a picture of them _before_ you clean them
- plugs, are the gaps set right (0.8mm I think)
- plug leads, try getting some new ones
- distributor cap - take it off, give it a clean, check for cracks
- check timing - if you don't know how to do it find someone with a timing gun and set it to around 6 degrees BTDC at idle (tune it once it goes ok)

Carburettor:
- were the plugs wet when you pulled them? If so the carb might be set too rich or the needle valve sticking and making it over fuel
- setup the carburettor (lots of instructions on line)

D

Thanks - that'll get me started

Assuming you have points, check the points gap and the condensor - These would be the symptoms of failing ignition components and I would guess is the likely problem - check the spark. If that's OK move on to fuel...

Well,
Just to add , has no points - electronic ignition , checked plugs - quite sooted up , cleaned , still ran rough ,spluttering in lower gears , then checked distributor gap , bit grimey , and the contacts looked a bit pitted , cleaned cap & tided up the contacts with some 800 wet & dry , ran a bit more smoothly- not perfect , but slightly better . Think I'll get a full set of plugs , leads & cap next week & swap for new , and then look at the timing & mixture .
Steve

Mine had similar symptoms, turned out to be the coil on the way out.

The weber 32/34 on these can give the same symptoms when the main jets at the bottom of the fuel well gets blocked easy fix just pull em out and clean,and check if gauze filter in inlet nozzel at carb is not stuffed

Hi all
It's definitely an intermitant issue , as this morning thought I'd use the Land rover to drive the 3 mile round trip for a paper - ran perfectly straight from cold . Buoyed by the amazing overnight change , a couple of hours later I decided to use it to out again ... Oh dear the issue was back, it idles OK , however as you pull away & accelerate under load it coughs , splutters & back fires . the only way to keep going is to keep dipping the clutch , giving it plenty of choke and give it plenty of welly , You can sort of drive through the rough up into 4th at which point it's a bit smoother , but still spluttering. Tried giving it some time to warm up , but no difference .
Oh on the point of the coil , I'll bare that in mind however , that's actually the only new part on the system , about 500mls old , so It's sort of be surprised .
So the plan remains the same , I'll start by working my way through the basic ignition components , plugs , leads , dizzy cap .
Cheers Steve

I'm going to say it will be the carb.
Ive got a 2.5 petrol and had the same issues, I cleaned the carb out with carb cleaner and commpressed air.

Weber carbs are very very fussy.

But, a mate fitted a new coil and also had the same issues, turned out to be a faulty coil.

What level is your fuel tank at?

First thing I thought of , as it didn't initially feel like running out of fuel , and low fuel light was flashing even though the gauge said 1/4 full , so I put in an additional £20. However it still persisted after that .
Steve

Could be it's picked up some muck when fuel was at low level
Try running it with the carb air hose off then block the carb inlet with your hand this some times will unblock a jet.

Check dizzy is advancing ok using a gun. Suck vac hose to check vac advance (engine off!)