I have 94 dodge shadow. Since purchasing the car 6 mo. ago, the car has had issue with either a high idle or low idle. Now recently, when I get about ten miles down the hwy., the vehicle chugges and sputters. The car can be put in park and revved up with no issues but if it placed in drive again it starts to chug when the accelerator is applied. If the car is allowed to cool down, it runs and shifts fine. An article had eluded to a lock-up solenoid. Any input?

 

The only thing I can think of is bad gas or maybe you got some water in the tank. Try getting a gas treatment and pour it in and see if this helps or even an injector cleaner.

 

Ok, I tried an oil additive and changed the oil filter. This did not resolve. I did determine that when the issue occurs, if I pull over and shut the car off then restart, the issue goes away.

 

Check your AIS- that is a insert on the throttle body with 2 wires going into it which controls your idle speed by varying the mixtrure. If it get stuck in the cold position, the engine idle very high (2,000+ rpm) and may get too much fuel when hot. If stuck in cold position, car will die when cold. On the 4 cylinder engines, the wiring lies next to/on top of the valve cover and the wire insulation get brittle/melts over time and may cause a short to the AIS, causing it to act erratically.