2.3L ('83-'97) Running rough within 5 min of driving.

[Trey3511]

I have a 1994 ford ranger 2.3 that I've recently gotten running again after sitting for around 5 years. I've replaced the fuel sending unit, fuel filter twice, new plugs and wires, new radiator, water pump, thermostat, air filter, and cleaned maf, iac, and throttle body. The truck runs great after I've driven it for around 5 min but when start the truck and usually when I shift to 2nd gear going down my driveway it boggs down and shutters and wants to stall. I usually rev the engine and it will clear out by the time I get to the highway. Any suggestions on what could be the problem? Thanks!

 

[Locotomb]

Probably dry rotted wiring harness resulting in intermittent shorts. Or corroded Connectors. Probably both. Clean all the connectors on the drivers side inner wheel well and inspect for cracks in the insulation on the wires. Especially around tight bends and around your shift linkage. Honestly, check everywhere cause I had a harness that had exposed wires at every connector due to dry rot.

 

[tomw]

Check the ECT and ACT sensors. The engine coolant temperature and the 'air charge' (incoming air) temperature are used by the computer to diddle the squirt time of the injectors much the same as the choke on a carburetor is used to enrich the cold mix. Check also the IAC as it should bump the 'cold idle' all by itself(depends on ACT & ECT to tell the computer..) and lower the idle when the coolant reaches running temp(actually before).
You also likely have a 'stove' around the exhaust manifold, a sheet metal dingus that wraps loosely, with a bendable tube to direct airflow. When incoming air is cold, a thermal vacuum valve will apply vacuum to a diaphragm, and pull a door into the normal airflow so the engine will be fed 'warmed' air from the stove. As the temperature increases underhood, the thermal will open, and the little diverter door will close, allowing external, unheated air to flow directly. If the thermal valve fails, cold external air will always be fed, and that can cause stumble, bucking, stalling, and all the other miseries of the world.
tom

 

[CAJones]

It only runs rough when cold? If you restart after it is up to temperature, what happens?

 

[RonD]

+1 On the ECT sensor, just change it out