92 Rodeo-Electronic Spark Control, Runs Waaay Rich

[colleen95608]

Hi All.
I'm hoping someone here can offer some advice about my son's 92 Rodeo. It is a strong running truck with about 170K miles. 5 speed transmission...he can't pass the California smog test because it is running very rich. The CEL came on and the code tells us the problem is 'Electronic Spark Control' and the 'Vehicle Speed Sensor'.

He also has a strange problem with starting it. After the vehicle has sat for more than a few hours it seems nearly impossible to get it to start...it tries, cranks over and over, but just doesn't catch. After much effort, sometimes priming it by removing the air filter etc and adding fuel, it does get going. Then it will cough and sputter as if it is running out of fuel for the first mile or so....after that all seems well. Starting it is easy if it hasn't been sitting more than 4 or 5 hours...

Any advice or ideas will be greatly appreciated....thanks so much!

Colleen...AKA Mom to a Starving College Boy