On my 91 305 TPI, I have recently been having some trouble. My engine seems to lunge, jerk, or cutout whether its sitting or driving.

Watching my RPM gauge, It will drop from about 2000 rpms at driving speed and almost completely bottom out and again and again. It seems to just do it randomly and the car defenitely loses power(rare occasions it backfires). Heres a list of all I have had professionally replaced:

Distributor, Cap, Rotor, Plugs, Plug wires, fuel pump, fuel lines, fuel tank.

Anybody know why it is doing this. I had taken it in to be checked out today by a mechanic and he said there was a defenite misfire but it wouldnt do it long enough for him to correctly diagnose the problem. The only two things I havent replaced would be the ignition coil and the ignition control module. Would it be one of those over the other because I cant imagine both could be bad.

Also If it is the coil, How to I go about correctly replacing the coil? I have the kind that is on the distributor.

Thanks a lot guys hopefully we can figure this out.

 

Anybody?

 

When were wires changed? Check that a wire has not been touching the manifold and melted. Just recently happened on mine.

 

Checked those and theyre all good!

 

Bump

 

I'm having the same problem on my 83 except it is happening all of the time. I would pull your ignition control module and bring it to an auto parts store near you, most "chain" stores will test the module for you. If it passes then start with the coil. Although your module might pass, check for signs of wear like rust or corrosion on the connecting pieces or signs of damage on the metal plate on the bottom of the module. It might be a good idea to replace this as well either way since it's not all that expensive. Changing the coil is easy, if it's one that sits on top of the cap, like you described above, then you probably have a plastic plate with two bolts sitting on top. Remove it and your coil is held down by four bolts and a couple of easy electrical connections, as well as a ground. If neither of these solve your problems, I would start thinking sensors, first EGR. Do you have a check engine light on?