Poor running

Please help, my series 3 petrol is a little poorly.

Sometimes she runs sweet then without warning she starts to backfire, it more of a pop than a bang. When she's popping every time you try to accelerate she try's to cut out, only way to drive is with choke fully out.

She has had a electric fuel pump fitted a few months ago so pretty sure everything ok with that.
I have had the carb to bit twice now, the second time it went in the ultra sonic cleaner at work. The carb is a twin port weber, not sure what kind, with a k n panel filter.

It almost feels like she getting to much air, I have tried blocking some of the filter but it no different.

The annoying thing is she fixes herself every time I get spaners close to her.

Any help or suggestion will be much appreciated.
Thank you
Dean

ive seen this before and you need a new head to manifold gasket and clean the feck out of both items before refitting then tighten them on good n proppa with copper washers and nuts

deffo getting air in the manifold gasket

Thanks johnny, makes sense. Will pull her to bits tomorrow and have a look

the two manifold need the 4 bolts slackening to allow them to move seperate to each other before refitting

Thanks James the helps appreciated.I forgot to thank you for help with gearbox, sorry. Turned out it wasn't detent stopping it selecting it was one of the reverse gate springs, it had snapped and got itself stuck behind the selecters

Think I found problem, removed carb and she has an adapter plate between carb and manifold. This has quite a few cracks in it. Problem is can't seem to find a new one to buy any ideas?

trace round the bugger onto cardboard cornflakes box 3 times

2 will be new gaskets top n bottom and the 3rd will be a template for getting a replacement

paint the original fekker with yacht varnish leave to dry for 24 hours then sand it smooth (the varnish will stay in the cracks) then refit with the 2 cornflakes gaskets and instant gasket on both sides of them and leave for a further 4 hours this should last a good while till yer get a replacement or find someone to make one

Bloody good idea johnny thank you. Going to kitchen to raid the cereal cupboard

I've made those adapters before, get a chunk of ally from some where and hack a new one out. It's easier than you think, just make sure it's a nice clean piece with dead flat sides. the holes are the easy bit.
A bit of gasket paper each side then you're sorted..

ERR4386 - PACKING CARB 2.5 PETROL - Defender 90/110 Parts

It's not an adapter but a heat insulator - quite a thick one too, similar ones on ford pintos are about 1/3 the thickness. I spent a good half hour last night dressing an old one up. I put some wet&dry on a flat surface and shined it up, wish I'd thought to varnish it first would have saved me a lot of rubbing!

Sounds like you have a defender carb and possibly a 2.5 petrol engine. I'd also check that all the right hoses are fitted to the carb and manifold and that your brake servo hasn't got an intermittent leak while you're about it.

dominicbeesley said:

ERR4386 - PACKING CARB 2.5 PETROL - Defender 90/110 Parts

It's not an adapter but a heat insulator - quite a thick one too, similar ones on ford pintos are about 1/3 the thickness. I spent a good half hour last night dressing an old one up. I put some wet&dry on a flat surface and shined it up, wish I'd thought to varnish it first would have saved me a lot of rubbing!

Sounds like you have a defender carb and possibly a 2.5 petrol engine. I'd also check that all the right hoses are fitted to the carb and manifold and that your brake servo hasn't got an intermittent leak while you're about it.

Click to expand...

Thanks for your reply.how do I check if it the 2.5 engine? And is there an easy way to check the brake servo?

I will order the insulator later, thank you for the link. Went up to a land rover specialist yesterday with it, he said " in my 32 years working on land rovers I've never seen one of them". I didn't hold out much hope of finding one.

he hasnt seen many petrols in his 32 years ,you can check servo by putting foot on brake and starting engine pedal should go sink a bit with engine running

jamesmartin said:

he hasnt seen many petrols in his 32 years ,you can check servo by putting foot on brake and starting engine pedal should go sink a bit with engine running

Click to expand...

That what I thought, shelfs was full of brit part stuff as well. Will only venture back there if stuck.
Thank again James will have a look as soon as she's back up and running

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Just order it from Craddocks or Paddocks with part number ERR4386, is the same part as on a 2.25 or 2.5 early Defender.

To check if pipes are the problem you can disconnect the pipe to servo and block it with a bolt or similar but don't drive like that or you'll need a strong right foot for the brakes!

To check what engine you have look on the _block_ near the front passenger side. There should be an engine number stamped on it. There's a list of engine numbers here: Land Rover, Range Rover engine numbers - by Glencoyne 4x4 (Thetford)

Thank you for your help ordering part today. Hopefully back on road soon.
Been driving other halfs car for a few day, how boring are normal cars, I miss my s3

I've just had a look to try and find what engine I have, i have followed the link and I don't think I have engine number. The flat bit of block is there but no number on it. Is there any visual differences between the 2.1/4 petrol and the 2.5 ?

Fitted the new carb insulator today, problem is still there. Sprayed brake cleaner whilst she was running and revs pic up when directed at the front of the carb,will pull carb off tomorrow and see what I find.if I can figure out what carb it is will order a rebuild kit.
Checked brake servo as well and that don't seem to working at all, pedal don't feel any different with engine running to when engine is off. Will keep you posted.

Take a few pictures of your setup we might be able to help.

Appreciate the help mate thank you.
The last photo is the side that when sprayed the revs pic up. It hard to be sure but seems the revs build when the spray is directed around mixture screw