my bently manual says the big round flap thing in the metering head/airbox should be flush or 2mm below the ridge...does this apply to uk cars,as mine was slighly high(btw what does the height affect?)..its a KR engine
don't know what the factory measurements are, but here's a bit of theory: its a bit difficult to describe correctly without going overboard on detail, but basically the flap is used to measure air flow in order to work out how much fuel is needed. as the disc rises, more fuel is delivered. the air-fuel mixture is adjusted by altering the relationship between the amount of fuel delivered for any particular height of the disc - not the relationship between air flow and fuel directly. this means that the rest position of the disc has to be calibrated such that the reltionship between air flow and fuel delivery is as close to linear (which is what we need for good fuelling) as possible between rest and full throttle. this is what the idle height allows some control over.
Some had a sticker on the plate with the height, the height altered slightly depending on year and model but they were very close to each other. Symptoms of the place being set too low, high or to one side was poor hesitation and poor pick-up (erratic idle sometimes). The favourite way to judge the height is to lay a 1p coin on the flap at its lowest point and the upper surface of the coin should be level with the ridge in the metering head (difficult to describe without a diagram), before adjusting the flap should be removed and the body and flap cleaned, refit the flap and then lift it checking it doesnt foul the sides.
Basically as above. The airflow flap is at an angle. When the flap is resting on the backfire spring one edge should line up with the top of the straight section of the body and lower edge should be about 1-1.5mm below the edge of the straight section.
You may have to feel blade the flap into the central position too. I didn't do this the first time and the car just wouldn't idle.
