300 rich on a hot day
#2
300 rich on a hot day
I have a 93 F150 4X4 300, E4OD. The truck starts fine, after putting in gear and rolling approx. 50 feet, will die. It is then hard to start, and once started, lots of black smoke, and cannot be accelerated without dying. This continues until reaching running temperature. After a 30 minute drive, gas is being pushed out of the front tank filler neck. The code from the check engine light is 179, which indicates system rich. I have replaced the oxygen sensor, fuel pressure regulator, and map sensor (the last two suggested by a Ford mechanic). I'm not convinced the problem has been solved, and if anyone has had a similar problem, I would appreciate any information.
#3
300 rich on a hot day
Since your problem seems to be temp related , has the Ford tech checked the resistance of the coolant & or air temp sensors ? These two sensors also control the mixture . The O2 only goes to closed loop operation when it has warmed . Connect a Dvom to both sensors and measure their resistance , cold they should read in the 24 to 37 Ohm range & at operating temp they both should be in the 2 to 3 Ohm range . A continued rich operation like you have described is going to be hard on the convertors .
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