92 amigo

ihave a 92 isuzu amigo with about 200,000 miles on it. the head has been replaced. 3 mecanics agree that it is running “too rich”. not one of them can figure out how to fix it. rule outs:tune up, coil, vacuum valve, hoses…any one have any thoughts? really appreciate any suggestions,92

A faulty coolant temperature sensor could be telling the computer the engine is not warmed up (even though it is), and the computer may be enriching the mixture, as it does on cold start, thereby making the engine run rich all the time.

Start with the simple things.

would this also make the thing hard to start…some mornings it takes me almost 45 minutes to get it started and hold, then it runs as if it is not in the right gear. thanks for your quick response.