91 Ranger- NEED Help

[Edcon]

Hey guys, I just bought a 91 Ranger with a 2.3. The first 2 days I had it it ran great, but Saturday I was driving on the highway, and it starting running very rough, the check engine light came on, and the tachometer dropped down to zero. Today I changed both of the coil packs, because I figured the tach gets its signal from the coil packs and the tach stopped working. It didn't fix it. I know the easiest thing to do would be to pull codes from the computer, but I have no way of doing so. Is there any thing else I might want to check before taking it to a shop? Any help would be great. Thanks.

 

[rwenzing]

I know the easiest thing to do would be to pull codes from the computer, but I have no way of doing so.

It is easy to pull codes yourself on pre-95 Rangers - no special reader needed:

http://www.troublecodes.net/Ford/

That site includes an OBD trouble code list as well.

 

[Edcon]

I also don't have a volt meter. I am looking for suggestions of things to check without scanning the computer. What could cause the tachometer to stop working and make the truck run as if it has a miss at the same time?

 

[410Fortune]

signal to the tachometer comes directly from the computer, it also branches to the diagnostics port for KOER and KOEO tests.

All you need is a paper clip to get your code via the CEL

 

[Az_NavajoRob]

Is your Ranger distributorless? If not, it could be the TFI module (grey plastic thingy that is held onto the dist by two screws ans the wiring harness plugs into it). If it is d-less then it could be the crank position sensor (sensor or the front of the motor by the harmonic balancer). Don't know how to test other than R+R then save the old one as a spare if that doesn't fix it.

 

[Edcon]

It is distributorless. I will look into your suggestions and report back. Thanks for the tips.