My blazer (2000 4.3 4x4) has a slight sputtering and I changed sparks and wires, fuel pump, fuel filter, flushed my tranny and changed distributer cap and rotor, last thing is the ignition coil....it looks very old but people have told me that the ignition coil should last the life of the car...asking for some help to pull me off the fence and just spend the money and buy one. OH and it only sputters between 50mph and 60mph.

 

You can measure the resistance. I had one on my Suburban that was low and changing it made a difference.

I got it off Amazon and it was about $21 for the AC Delco unit.

 

what should I charge ?

 

I was suggesting you could test the coil resistance to verify it's bad. I forget the values but you should be able find them online.

Or if you wish to replace parts replace the coil. I replaced the ignition control module att the same time. I just wanted to fool with it once but that's me. It was another 69-65 bucks

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Resistance checks mean little. It's a high voltage transformer and has two inductive windings. They can be shorted or arcing over and an ohm meter wont show it.

FIRST thing to check is the voltage at the ignition module. Bad wiring can starve the ignition of a lot of energy.

Yes, high speed miss can be a coil or other arcing from bad wires. The ignition system has much less time ( dwell) at higher speeds to charge the coil.

 

If you have a scanner (or access to a scanner) check the cam position sensor sync. If it's not within 2 degrees, it can cause spark scatter in the distributor, especially at higher speeds.

 

He said change the coil, not CHARGE IT. He suggested you test the ignition coil first. He also suggested you may want to change the Ignition Control Module at the same time.