Hi, I have a 1994 2.3 ranger that has sat for a long time off and on and then sat for an even longer time. It only has 69,000 miles on it.

I've replaced the plugs, plug wires (originals were fine) have added a can of fuel injector cleaner.

I've cleaned the map sensor and sprayed the throttle body down as best as possible without fully removing it.

I've also added premium fuel.

Basically, when it starts, she purrs perfect cold. For about 5 seconds... then the RPMs fade down and she starts a rumble that shakes the rig. It runs and drives fine but should be able to idle much smoother. Like the mirrors shake.

I suspect it's a fuel line issue as well. It seems like its sucking for gas? I'm inclined to say it idles better after driving for a bit but I'm not certain.

Does this truck have a fuel filter and is there merit for changing injectors? I'm hoping fuel cleaner and time will help. How do I solve the rough idle?

 

Try replacing the ECT sensor, its not expensive, ECT(engine coolant temp) was added to fuel injected engines(nothing to do with dash temp gauge), so computer could run Choke Mode
All gasoline engines need to be "choked" on cold start, which means high idle and RICH fuel mix, also advanced spark timing

If ECT is working OK you should have a high idle after cold start, 1,000rpm+, then idle will slowly go down as engine coolant warms up
If this is happening then ECT sensor is fine

 

The idle drops in 5 seconds... not when the engine temp has warmed up.

Seems when she drops to 800 ish... she rumbles. There's no tach... just by feeling. I just replaced plug wires... unnecessarily. :/