92 Ford Explorer 4 L. When it's cold it has a loss of power, but as I raise my foot off the gas it surges ahead. It idles poorly. Once it's warm it's fine, but of course the engine light is on. I can't get it up to 20 km when I push the gas pedal, the whole engine rocks at a stop sign and I can't get it to idle steady...I can keep it going, and like I said it clears up once it's warm.
So far I've changed the Mass Air Flow Sensor, the Idler Control Valve, the intake air temperature sensor and the coolant temperature sensor and the throttle positioning sensor.
I'm thinking of the map sensor next..maybe look for vacuum leaks..check wires going to these sensors with a metre...Any ideas? I have a automotive manual here...been reading it...but I haven't been able to hit the problem.

 

Look at the vacum tree at the rear of the Intake, they tend to swell the lines with oil leaking on them and fall off. Also they can have the lower intake gasket leak vacum when cold and be better when warm. This sounds like your most logical problem.

 

Thank you We'll check this out over the weekend