Hey all. I have a 1993 Ranger.. 2.3L motor with 178K on it, 5 speed manual. It's been running pretty well for the last 80 thousand miles or so. But today I noticed while cruising, the truck is missing.. sortof. it feels like it's missing but it's not associated with the funny noise of a miss. It just chugs out a little. Also, occasionally the aftermarket tach will bounce upward while at a stoplight. Not as if I rev'd the motor, the tach suddenly jumps upward approximately 2 or 3 thousand Rs... A while ago I had a grounding problem that I solved by replacing the negative battery cable connector. I double checked that and there's no problem there. I haven't noticed a problem with gas mileage. Also, on the way home I stopped about a mile away from my house, and disconnected the primary coil, drove half a mile, and then swapped to the secondary coil., and drove another half mile as sortof check to see if it affects the secondary or primary coil, as I was first expecting a bad plug wire or something along those lines. I had no tach signal as a result, but I still felt the slight miss-type chug. Plug wires look great, and when I did the timing belt about 3 months ago I had the plugs out and checked them for wear, gap and carbon build up, and they all looked great.

Anyway... tomorrow morning I'm going to take a closer look at it, but for tonight I'm not going to mess with it. Anything I should look for in particular? Thanks much.

 

The tach is bouncing because it is getting a bad signal, an intermittent signal, or it is defective. If it is either of the 1st two things, that could affect the signal sent to the coil(s), causing a miss. Make sure that the ignition module is mounted tightly and all the connectors are tight. Ditto for the spark plug wires. You can take the module in to be tested at an auto parts store, but the test will not show an intermittent fault unless you are lucky.
tom

 

Are you talking about the ignition module bolted to the driver side of the motor buried in the intake manifold?