Club 80-90 Forums

Please can anyone shed any light on my fault. When i start my 2.0l air cooled (twin carb) devon, it runs fine (although doesn't start very well) until it gets warm, then when i try to accelerate it runs lumpy and mixture is very rich and smoky, and wont drive (but fine on tick over). I have replaced coil, checked the air cleaner temperature control, the valve works when vacuum is released, and the automatic chokes are coming off ok. I have also tried disconnecting the air cleaner, then when the engine is cold runs fine again.

What colour smoke would you say you are getting, black or blue?
If its blue, could be oil getting past valve stems or piston rings. Could be fouling plugs and making running difficult. May only occur when oil is circulating and thinner due to warmer engine.

Black sooty smoke as if mixture too rich

is your idle control box still connected? its the black box on the left of the engine bay with 2 round plugs in the bottom of it? if it is pull both plugs and join them together,, then try it.

yep still there thanx will try tommorow.

check the timing too

Just a thought, shouldnt be this though... Disconnect the automatic choke control electrical cable when a little warm. Just in case somethings not right in there. Let it run for a while and see what happens.

tried the joining stabilising plugs together, still doing it when warm , timing spot on, when i disconnect vacuum advance ,engine increased then when i reved it ran rough, disconnected chokes no difference, but what i have noticed is a load of gaffer tape around what looks like a junction of vacuum pipe? (approx 10 to 15mm tube diameter) that runs to each inlet manifold then branches off on the lhd side engine compartment near carb would this have any thing to do with it?. when warm i notice the smoke from exhaust is grey/back and smells very petroley.

sounds like you have an airleak there....gaffa tape will get you home, but it expands when hot. you really need a new hose/pipe

You could be right i rekon, what does the pipe do? does it feed brake servo? would it make it run rich or weak an air leak?
do i have to remove cyl heads to do push rod tubes on my 2.0l Aircooled?

thanx everyone for your help much appreciated

spud wrote:You could be right i rekon, what does the pipe do? does it feed brake servo? would it make it run rich or weak an air leak?
do i have to remove cyl heads to do push rod tubes on my 2.0l Aircooled?

thanx everyone for your help much appreciated

Runs rich, feeds servo, and you don't take off heads on an air-cooled ...short but sweet answer