My car has a miss at low rpms in overdrive. So far I've replaced the plugs, wires, cap and rotor, and installed an Accel super coil. I also repaired a major vacuum leak. The car had previously had a slight miss to prompt the tune up, but it is much more pronounced now and it has thrown code 41 for no distributor reference signal when idling for extended periods. The car is otherwise stock and unmolested as far as the engine goes, and this is really the only problem ive had with it so far. Any ideas on what might be up? Id like to get it running smoothly again as I may be driving it on a road trip next month.

 

Cleared the code today, found another unplugged vacuum line and plugged it in... and the car still is running rough under load :/ hasn't flashed the cel yet though.
I have tested the ignition control module and the resistance was within spec.. also checked all spark plugs except #7 and they appear to be okay. I also sprayed all the vacuum lines with intake/tb cleaner and didnt find any other leaks. My only guesses ar this point would be wires, coil, or the map sensor. I am leery of the map sensor. I don't think I was testing the voltage right, but if I was, I wasnt getting the change I was supposed to notice when plugging/unplugging vacuun lines.

 

The plot thickens...I changed the coil back from the Accel to the factory one and the miss/cutting out now occurs at around 2k rpms with the tcc locked up under load as opposed to it happening at around 1200 under the same conditions. I also checked the est system by jumping the test terminal at idle, so I know it is operating properly.
Ill be checking the intake manifold for leaks tonight and I guess ill try another set of plug wires... if anyonr has any ideas please feel free to chime in, this is getting frustrating and I'm running out of ideas.

 

Code 41 still hasn't come back, so I'm just gonna write it off as having the plug for the distributor loose.

The misfire/ surge thing remains though.
I've changed the fuel filter (old one was like new so I'd imagine the carb is clean), the accelerator pump seems to be operating properly, I unplugged the vacuum line to the EGR and plugged it with a screw, and it's still doing it. I also sprayed the intake with carb cleaner and didn't have any leaks.


At this point, my only guesses are that the surging/ stuttering feeling are the fuel pump, something internal in the distributor, or something internal in the carb. I also noticed that the coolant temp sensor is pretty beat up and the wires running to it are exposed. Could that have anything to do with it, and would it throw a code if something's wrong?

If nothing else I guess I'll just start throwing parts starting with the cheapest stuff.