95 f-150 4.9.
i changed my oil andair fliter....when i started my truck it ran like crap. would rev up die down. thought i had a bad vacume or somehtign wiht the air filter but theres no MAF sensor so no big deal.

i have changed the manifold gasket thought maybe bad reading on the o2 sensor. nothing. i did a tune; up-cap wires plugs rotor. nothing. plug the diagnostics computer to the truck and it stalls the truck out, the computer also says "vehicle not responding". unplug the EGR valve while its running....no difference. unplug vacume lines and it picks up idle a little bit but still runs bad. i an clueless

i just checked a bunch of vacume hoses. itested the fuel pressure. i chaged the throtle positioning sensor, i changed the MAPP sensor, i changed the EGR valve. i changed a few other parts that i have no idea what they are called.

symptoms: the truck has a rough idle, black smoke and a sooty residue comes out fo the exaust, it stinks like a bad cat. it hessitates when you throttle it quick, almost dies out. if you rev it slowly it will continue ot rev up. yes the check engine light is on....im so confused..

 

Black smoke, engine flooding. Blue smoke, oil burning. White smoke, anti-freeze.

The engine shouldn't need to be running to pull stored codes, reset the computer and drive it awhile and see what you get.

 

i cant drive the truck anyplace. it has no power and when you throttle it, sounds like the engine is breaking down. when the truck is off the computer still cannot read the codes. could be my truck or coudl be the box...idk. im goin to put anew fuel filter in and check the cats and see what happens from there.

 

Attach a vacuum gauge to a manifold vacuum source, and see what it reads at idle. Let it continue to idle for 5 minutes, and check the gauge again. Post the results.