The car had some problems a week ago and after trying to figure out what was up with it I decided to limp it over to the shop. The shop took care of the hard cranking problem (bad conductivity on the negative battery cable). But the car still surges badly and dies randomly making it undrivable.

The car will run fine when it is cold but after it warms up a little it will start to miss very badly. When I attempt to drive it like that it will surge up and down 1000 rpm at a time and if a lot of gas is given it will backfire. The car will basically not go over 10 mph in the shape.

The shop could not tell completely what it was because the problem is so intermittent and comes and goes. They did say however the secondary ignition fails when the problem shows up, but they can not rule out the primary ignition. They wanted 600 bucks to replace the ignition coil, ignition module, and pickup coil. Since they couldn't confirm what the exact problem with at least some certainty I had it towed home.

I am going to replace the secondary ignition components myself, but what parts of the system make up the primary ignition components?

 

Primary side = the parts that work at 12V
Secondary side = the parts that work at high voltage; i.e. handle sparks

Primary = module, pickup coil, coil
Secondary = coil (has 2 windings, turns 12V pulses in the primary winding into 30 kV pulses in the secondary winding), coil wire, cap, rotor, plug wires, plugs

Sounds to me like a good place to start would be a cap and rotor.

 

Primary is the low voltage side(most of the stuff the shop recommended replacing). Secondary is the high voltage side(half the coil,wires,plugs).

 

Turned out to be the ignition coil.

 

i've had sort of a similar problem. what would cause the ignition coil to fail every 6-9 months?

 

Interesting question, one that I would like to know the answer to also. My car ran fine for a week with the new coil and now is doing the exact same thing it was before. I have a feeling the coil failed again.

What could cause a new coil to fail?

 

Usually, too much plug gap....

Anything over .045" greatly stresses everything in the secondary part of the ignition; but especially the coil, which has the thinnest insulation of any of it.

 

$600.00 Never go back there again..