My 1996 ram 1500 with the 360 is running so rich i can smell unburned gas and it only gets 6 mpg. I hear there is a coolant temp sensor that doesnt let the computer control the mixture until the truck is warm. Does anyone know if this truck has one?


By the way I have replaced Cap, Rotor, Plugs, Wires, O2 sensors, Plenum gasket, Air filter, and PCV valve trying to get more gas mileage out of it. (went from 4mpg to 6 mpg)


But still when i look in the tailpipe it is covered in black soot and the truck always smells rich.

 

Oh I also forgot to say that my temp gauge in the truck is working, I would figure the sensor for the computer uses the same one for the gauge but maybe there is a separate one? hopefully because i am running out of ideas. PLEASE HELP!!!!!!!

 

check your cat, it could be plugged. measure the inlet & outlet temps, output should be hotter by at least 50 deg f for the cat to be working properly (warmed up of course).

swap out your IAT sensor, mounted up by the #2 cylinder and check the wiring. your motor sounds like it's in open loop mode. what temp t-stat do you have in there?

Check for any engine codes

 

It has a brand new cat, Its the stock t-stat which i think is 200 but im not sure.

Changing the IAT sensor was my next guess so I will most likely do that

 

ok so I changed the IAT sensor and still runs rich

Any more suggestions?

 

Have you checked the O2 sensor(s)? When they fail, the computer will run in limp-in mode causing the engine to run rich. Usually when this happens it will stumble on accel from idle. Have you pulled any codes?

 

O2 sensors are also new (engine codes were right bank O2 sensor failure, so i changed all the O2 sensors, also there was a system too lean engine code and i traced it to the plenum gasket and replaced that as well)

As you can see I have done almost everything anyone can think of. This is a very confusing problem