Hi. I should say I am a definite novice at this but am posting here after having gotten nowhere with the Haynes manual. I'd be very grateful if any of you were able to help. I recently acquired a Rover Metro 1.1 with a K8 series engine. It runs well but occasionally the idle is uneven and will cut out when you come to a standstill with the clutch down. I realise there could be many explanations for this but have some theories in particular before taking it to the garage:

- the air temp control valve is where it should be but not connected to anything else apart from the intake manifold i.e the air temp is not registering anywhere. There is a yellow tube with what once was a seal on the end that was loosely connected to this valve but obviously without a seal. The other end of this yellow tube is not attached to anything. There is a floating black tube of the same diameter attached to a component that I can't identify but that has a sort of diaphragm on the top similiar to a gas canister. Is it possible that these two tubes black and yellow ought to be joined by a missing female part? I have some pictures but don't seem to be able to easily post them here (perhaps it is more straightforward in private messages) but am minded at the moment to simply connect these two together

Hi, The way that these tubes go is as follows - there are two circuits. The first is the temperature-controlled inlet valve. A red tube connects to the top of the carb close to where it meets the inlet manifold and goes under the air filter cover to a Thermac switch. The other terminal from the Thermac switch is connected to a yellow tube which passes under the distributor and connects to the yellow terminal at the valve on the air intake hose where the intake meets the flexible hose.

The second vacuum circuit is all in black tubing It starts at the carb where a thin black hose leads to the coolant switch built into the metal coolant tube at the front of the rad near the air inlet hose. The other terminal of this switch is connected by a thin black hose to a "T" connector on the distributor vacuum advance unit. Another black hose from the "T" piece connects to the control valve on the charcoal cannister - the valve is marked "Rochester".

The purpose of the yellow/red circuit is to select the source of air for the carb depending on inlet temperature - blending hot and cold to try to maintain a constant temp for predictable mixing of air and fuel.

The purpose of the black circuit is two fold. Firstly it prevents vacuum advance of the ignition until the coolant temperature has raised to 77 degrees - to warm up the cat more quickly and secondly it opens the cannisted purge valve when the coolant is hot to draw stored fumes from the fuel tank into the engine inlet.

I have tried disconnecting and plugging both of these systems on mine to see what happened and they both affected driveability badly.

Good luck!