I am new to this group and am in a little bit of trouble with my 1997 4.2L 4x4 F-150.
The first problem I have is today I was talking to a friend of mine on my C.B. I decided to put the accelerator to the floor. Then I heard my firend tell me that I left a cloud of black smoke behind me. I was as hard on the next take off and nothing happened. Then I gave it to her again and another cloud was left behind. There is an excessive amount of soot in the tip of the tailpipe. My friend thinks it is just a carbon build up. What do you fellows think.
Then my truck will sometimes spit and sputter then die or stall when the clutch is engaged. I have replaced the Idle Air Control (I.A.C) which solved nothing. This was the advise given by the mechanic I usually go to. So needless to say I would rather not pay for guessing games. I have replaced the fuel filter, plugs, wires. I was thinking that it could be the P.C.V but I can't change that because I'm not sure where it is located.
I would appreciate any help I can get. Thanks in advance.
Fordboy1997

 

Pvc check valve should be on the top edge of the r/h valve cover
How were your plugs? (colour)
I had catatic converter break up in side and block the exhuast flow. causing some black smoke + soot.

 

The plugs seemed to be like new when I changed them. The plugged cat also crossed my mind.

 

its the upstream O2 sensors, they will either tell the PCM to send too much fuel(black smoke) or too little(rough idle/lack of power). go to autozone or napa. they're $50 a piece. remember its probably going to be the upstream sensors.

 

I had carbon build up that created black smoke just like your talking about, run come LC/FP and it should take care of it (if that's your problem)