I have a '91 Ranger 2.3 with the distributorless EEC-IV ignition system. Awhile back I noticed the tach drop below 1000 rpm while driving down the highway. It would come back up in seconds. Since then it often stays below 1000 rpm, and when this happens the check engine light comes on.

Sounded like the crankshaft position indicator to me, but I had the codes read & after further investigation, they told me the Mass Airflow Sensor was bad. I then checked it myself & found it to be okay.

I'm sticking with the crankshaft pos. indicator, or connecting wiring (especially because the problem is intermittant), but am having difficulty tracing it all out to find a testpoint. There are four wires coming up from the sensor.

Moving wires & connections seems to have no effect in correcting the problem or causing it.

Can anyone HELP???

 

Welcome to FTE!!!

I'm not familar with the 2.3L but I'm sure someone will be able to help.