engine seems to run very low idle when warm and sometimes cold.

is this a carb tuning problem or could there be another reason?

plus do get a smell of petrol once running for a while.

on another note, when was on motor way would suddenly get loss of power and had to pull on to hard shoulder. left it for a while then it started again?? fuel pump issue maybe, any suggestions will be greatly appreciated. thanks

Check the idle speed, and idle mixture on the carb for the first problem. The loss of power sounds like carb icing, check your warm air hose from the exhaust manifold and also make sure all vacuum hoses are connected.

what car are we talking about here? what year is it?

I'm guessing it's a Coupe S badged as a GT?

I'm guessing it's a Coupe S badged as a GT?

correct

thanks for the responses, any more ideas of the problem, will have a look tomorrow. thanks

is the hot air pipe missing from the sheild on the top of the exhaust manifold to the air intake?

is the hot air pipe missing from the sheild on the top of the exhaust manifold to the air intake?

not too sure, going to check it now. thanks

Yeah do that as I said and if it's there and in good condition then check the vacuum hoses and that the warm air flap opens and closes as it should on the inlet pipework.

new leads,hot air pipe, secured all hoses, running a treat. thanks for the info :)

i tell a lie, once its getting up to temp its cutting out at idle again, also still looses powers and the dreaded 'judder'

if this is a carb tune problem, and links or info on DIY would be great.

what are the other possibilities? thanks in advcance

Poor warm-up: pipes to the autochoke unit bunged up ?

Losing power: rust through the fuel filter blocking a jet or air leak ?

Smell of petrol : airleak ?

Maybe accelerator pump diaphragm has a split.

http://www.ruddies-berlin.de/

Pierburg 2e3 membrane.

Edited 22 January, 200818 yr by dvderlm

Poor warm-up: pipes to the autochoke unit bunged up ?

Losing power: rust through the fuel filter blocking a jet or air leak ?

Smell of petrol : airleak ?

Maybe accelerator pump diaphragm has a split.

http://www.ruddies-berlin.de/

Pierburg 2e3 membrane.

thanks for the reply, i have changed the fuel filter and still looks clean after w eek or so of driving, so guess can ruel that out. as for the air leak?? i how do i test/diagnose this?

can i replace the diaphragm separately or does the whole unit have to be replaced? thanks

as for the air leak?? i how do i test/diagnose this?

can i replace the diaphragm separately or does the whole unit have to be replaced? thanks

Diaphragm is under cover with four crosshead screws operated by lever at back of carb below fuel inlet pipe.

You can replace just the diaphragm and other Pierberg 2Ex of same era (Golf Mk2 1.6/1.8, Ford Sierra CVH 1.8) could be a suitable donor from scrappy.. if their rubber is not split. Service kits usually contain them brand new as the rubber vulcanises. I think Golf's may have 14mm brass operating rod while Polo's are 13mm, but shouldn't be problem ... the lever might need bending.

To check if its split you might be able to detect some petrol if you wrap tissue benaet the lever on cold engine and pump the acceleartor pedal to the floor a few times. If any petrol leaks out there's a split.

Replace any vacuum hose (the 6mm pipe to the front of the carb) if it has surface cracks or splits. Hose is cheap. Sometimes even free if you ask nicely.

A leak at the base gasket can be detected by spraying shaving foam (cold engine!) around base of carb and then start it and watch while it idles. You'll see big bubbles form. New rubber gasket (hard to source) or tube of hylomar instant gasket to fix. Three bolts go all the way down to the rubber. The rubber is held to the manifold from below by four studs.

Hope that helps.

fantastic reply, just what i was looking for. been most helpful thankyou :-D