I own a 98 Dakota Sport. 318 with @165000 miles. (Well taken care of as far as oil/fluid changes... general maintenance) When I first start it in the morning or on the drive home from work, it runs really rough. It idles fine but when I start down the road.... No power unless I floor it. What I would call normal throttle for driving at 25-40 MPH hour REALLY spits and sputters unless I give it a lot of gas. Once it gets to operating temp it seems to be fine. I need some ideas on where to start. Have changed plugs, wires, cap and rotor. Throwing no codes. Thanks in advance.

 

Try replacing the coal can maybe air filter is there any engine codes?

 

no codes... air filter is clean.

 

I'd try coil or distributor cap?

 

I have replaced the rotor and cap... wires and plugs also. Is there a way to check the coil for proper operation before replacing it?

 

Temp sensor? If you have a scanner (or access to one), it only takes a second to check it.