Well, amazingly I?m having the SAME problem right now!!!!! I?ve got a
93 mustang LX 2.3L. Although mine might be a bit different as I don?t have the distributer. Let me tell you what I?ve done the past week including today. I first though idle mixture sensor, cleaned then replaced it. I also took a bottle brush to the throtle body to clean in it as well. It did make a difference in the idle, but didn?t fix the tach or the weird bogging and bad idle (sometimes - at least till it all of a sudden fixes itself). I then changed the air charge sensor in the air box, didn?t do anything! Then I changed the ignition control mod. on the lower intake. That didn?t do anything but cost me 130.00. I also had a grinding noise from the fuel pump so I checked the pressure and it dropped so I changed the fuel pump. Then I decided it could be the crank-position sensor. Changed it for another 100.00, and the Crank sensor was 117.00 also. I also got a code from the comp. that the primary ignition coil was bad (mine is the dual plug motor). So while at the junk yard for another car I picked up some "tested" coil packs. I changed them both and nothing was different, so I don?t think it?s the coils or it seams I?d see something different good or bad. So, maybe we can help eachother (maybe I can save you some money by my mistakes) I?m not finding much info on this problem either. I can give you two web pages to help you check that eec-iv for the codes though. Here they are -
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Maybe that will help, but prob. not. I?ve been told it could be the "Power Control Module" which is on the pass. fender and looks like a little brain box. It actually gathers the info from the sensors and relays it to the processor. I talked to a ford master mechanic and he said he doubted that was it, but he also told me these other things that didn?t worked would. The parts guys at the dealership said they?ve seen the relay box shut the fuel pump down and re-start it so fast it just put a skip in the motor, but I?m not too sure of that. I?m going to get a box and maybe the entire eec-iv monday evening. Unless I find something else to look towards. I will keep you updated and would appreciate the same. Billy