1992 F150 5.0 Running Really Rich Of Fuel, Runs Rough And Black Smoke Everywhere!!! Whats Wrong

 

Is the 'check engine' light working (self-test at start-up?), and is it on? If so, the quickest way to narrow this down would be to pull the codes to see what the computer has flagged. Suggest to pull the codes anyway as a first step - see if anything interesting has popped up.

If not - ugh, could be a lot of things.
* Has any work been done recently leading up to this event?
* What kind of shape are the ignition components in - plugs, wires, cap, rotor, coil? When were they last looked at, or replaced?
* How are the air and fuel filters?
* Did this problem come on all of a sudden, or has it been a gradual change?
* Does this problem seem worse at certain operating conditions, so bad that you can't get it out of the drive, or what?

Some other thoughts are the MAP/MAF sensor, or timing issue (incl. timing chain jump).

 

Mix issues have dozens of possible sources, and the ECU's self-diagnostics are your best bet to try and track it down. If you turn the key on but don't start the motor the CEL should stay on steady. If not, the light is broken but that's not a huge deal. Buy an EEC-IV code scanner at the local auto store, they run about $20 for an Actron Ford/Lincoln/Mercury scanner. Plug it into the test port on the driver side underhood, turn the key to on, and watch the flashes carefully. It's a good idea to record the flashes/beeps with a camcorder or cell phone camera with video mode so you don't have to do this several times to verify the code.

If the problem occurred suddenly then chances are one thing died, which makes fixing it simpler....once you figure it out. If it's been getting worse in time, chances are it's multiple things that were not maintenanced as they should have been.

 

everthing is new no codes, new wires, cap rotor, plugs, cleaned intake, iac,egr,etc a little better but not right yet!

 

everthing is new no codes, new wires, cap rotor, plugs, cleaned intake, iac,egr,etc a little better but not right yet!

 

• In addition to what was already mentioned:
• The ECT (engine coolant temperature) sensor, AIT (air inlet temperature) sensor or the fuel pressure regulator.
• Both the ECT and AIT can make the engine run rich if they falsely sense the the engine is cold.
• As the fuel pressure regulator ages the internal spring gets weaker, as the spring gets weaker the fuel pressure rises, when the fuel pressure is too high the fuel injectors dump too much fuel into the manifold each time they open, this causes the engine to run rich.
• Check the fuel pressure with a pressure gauge at the valve on the fuel rail, if it's much above 35 psi with the engine idling (40 psi is too high), then replace the pressure regulator.