OK

On top of the FI pump there is a device with 2 coolant hoses going to it. This is the Warm Running Device and it enriches the fuel for cold starts and leans out the mixture as the engine warms up.[ that is the reason for the coolant hoses]
On the rear of this is a small can air filter. When the car is cold and running , take a hose and put one end on the filter intake and the other end in your ear. You will hear air being drawn into the filter..as the engine coolant reaches normal temp, this device will cut the intake air OFF and you will no longer hear it. It it works, that is not the problem..but if it does not , then the engine is running rich b/c the device is dirty and sticking open. It can be cleaned and oiled.
These filters also become blocked with dirt, so I always just unscrew them before doing this test to make sure they are clear [ I think it is 22mm/ or 7/8th]
That is the next test.
There are others, but there is a sequence...

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A Dalton