What could cause an ignition module to go bad on a Chevy S-10 2000?

Question

My mechanic just changed the ignition module and got the engine to stop micfiring, but the vechile is still idling oddly. Which was happening prior to the misfiring. He believes that is what caused the ignition module to go bad, but is going to get back with me tomorrow. I would like to know if anyone has any clue as to what this is? Thanks in advance for any suggestions.

Answer 1

Heat/moisture/excessive voltage is what causes them to go bad(barring accidents)

Have you replaced:

spark plugs(properly gapped)

spark plug wires(splurge on them they make BIG difference)

New rotor and cap

New air filter

New gas filter(and try higher octane)

Oil change and filter

Check air pressure too(monthly- trust me on this)

Check timing. adjust as needed.

Replace wires carefully one off one on keeps you from mixing up which goes where on engine or dist cap.

As you do parts and finish steps start engine between to see if better(also allows you to know you did something wrong WITHOUT having to wonder about it all!

Now to fun parts. Disconnect battery after all above. Use that battery brush you bought(pays for itself ). This resets settings so you need to take it for a drive above 30 mph.

The plug/wires usually solves problem. The above(including brush) will be under $100- barely.

Still having problems? Then you could have a vacuum leak... check all
the rubber hoses under your air cleaner(do this when changing
air filter- take cover(top) and housing(bottom) off. Remember those hoses there that have to be reconnected to correct places
for proper operation. Those hoses should be crack free. Use silicone(only good silicone spray NOT wd 20 or 40(twice as goodlol)) Silicone preserves rubber and may swell and seal lil cracks. Wipe excess off. WD actually attacks(breaks down) rubber. WD sprayed on metal parts can clean them well- wipe off excess. Use WD to clean air cleaner pan before reassembly.

Lastly poor coil connection or cracked coil(does it get worse when raining)?

Also check with voltmeter at battery with engine running. Rev engine. Check for wild voltage swings(bad voltage regulator).
Typical readings 12 to 14 volts.

If all the aboves fails to fix... get gun shoot truck, mech, me, yourself... me daughter had one that a shade tree mechnic had REMOVED the air filter... helped for a couple hundred miles- total loss afterwards. explained why the oil was mud(lived on dirt road).

Answer 2

If he just replaced it and the truck is still not right, it sounds like one of the coil packs could be bad. A mechanic really can't know whether it's the coil pack or ignition module on this design. You kind of have to do a hit or miss. I keep a spare coil and swap them out to troubleshoot this problem. If the coil doesn't fix it, then the ignition module will. That way, you only have to pay for one part rather than two. I would imagine your ignition module may be ok, you probably just have one of the coils going bad. Good luck.

Answer 3

Sometimes electronic parts just quit.
It happens to computers, cell phones, IPods, cars, trucks...
There may be something else causing the truck to idle badly, fuel injectors, PCM (Powertrain Control Module), bad spark plugs and/or wires, MAF (Mass AitFlow Sensor), etc.
I'm not convinced that idling badly would kill the module unless there is some other defective component.

Answer 4

A DVOM (digital-volt-ohm-meter) can be used to check the coils.
It sounds as if you have another problem. Normally if an ignition module goes bad, it doesn't cause a misfire. Plug wires and coils,however, will cause it to misfire.

Answer 5

Heat causes most of the problems here. But you may be getting moisture in sensors somehow.