2002 Ford Explorer has a rough idle, and jumps when put into gear.

[kenhill]

We have a 2002 Ford Exploreer 4.0l. When we start it cold and place into gear, the engine rpm surges up and the car leaps forward or backward. Seems to be a cold start issue. The car also idles rough. If it does not start the first time, on occassion, you have to crank 5 - 10 seconds and then it seems to emit black smoke until clear.

I have replaced plugs, wires, air filter, idle air control, and Oxgen sensor (only driver side one before cat converter and added several cans of seafoam to tank. No Improvement.

Any ideas? Intake gaskets next?

 

[BrooklynBay]

Welcome to this forum! I've moved your thread into the stock 2002-2005 section. Did you check to see if there are codes stored?

 

[kenhill]

2002 Ford Explorer has a rough idle, and jumps when put into gear

Not yet. Will do next.

 

[Sbyrne97]

Throttle Position Sensor maybe...also if there is black smoke your engine is full of carbon build up...you might take the intake off and clean your throttle plate odds are there is a lot of build up on the plate which can affect your idle

but, it may be the crankshaft Sensor...it can cause many problems to modern cars today

 

[kenhill]

Checked codes

No codes stored. I am surprised I can have this issue without a code. Obviously something is wrong... lean condition, bad sensor...

I think I read other posts that said not to clean the Throttle body in 2002 Explorers?

 

[BrooklynBay]

There is no problem cleaning the throttle body.