I have a 95 LT-1 and in trying to eliminate a miss problem I am considering replacing the coil. I assume I can try that first and omit replacing the module? Anyway, is the MSD #8226 a direct replacement for the stock coil (pictures look similar to stock with the same connectors).

Thanks,
Doug

 

miss? there are more likely causes then a coil.

What is the service history? mileage?

If you want to get a better coil, check out the GM LT4 coil.

If the module is bad, then the car won't run worth crap... period.

Where is the miss? Idle? Low RPM? High RPM? Under load?

Things to check:

Optispark
wires
plugs - especially if they are OE AC Delco platinums. Those POS's will loose the ground strap platinum plug, which will cause the gap to grow from .050 (spec) to .065 (not spec).

 

Just replacing parts without knowing that the part you're replacing is the cause of the problem is, ISN'T the correct way.

This is what "parts changers" do; not mechanics. Even if you don't consider yourself a "mechanic", just changing parts in the hope of hitting on the right one still isn't the way.

You first diagnose the cause, then - if necessary - buy the needed part. Why waste time and money on parts you don't need.

Coils and modules can be tested to see if they're good or not.

Jake

 

I exhaustively posted numerous previous times about my miss. In brief, it is almost always there at idle and gets worse if I turn on AC. Going up a hill in OD really sucks. I initially had this problem a few years ago and the dealer replaced opti and plug wires in 6/2002 but miss came back. In 10/2002 dealer changed opti again plus spark plugs and miss was gone until about 6 months ago.

I noticed bad corrosion on the ignition coil wire (from the opti) at the coil end and cleaned up. The car ran like gangbusters for about 3 days (no miss at all) but then the miss came back with a vengeance. I recently took it to the dealer who started looking at things but then stopped when seeing I had a few minor aftermarket parts. They did not notice anything bad when looking at a few plugs and the o2 sensors.

No codes have ever been thrown.

I just figured the coil was a relatively cheap item and it certainly wouldn't hurt assuming the MSD is at least an upgrade from stock. I will be trying to get my car into a local independent this week or next for other work, during which time I will ask him to try and track down the miss. The trouble is that most "experts", including mechanics will quickly shout OPTI and I am not convinced this is the problem. But there are precious few real diagnosticians around these days. Also disheartening are the plethora of posts from others on this forum who have changed everything but the kitchen sink trying to get rid of very similar sounding miss problems with no success.

 

You can do the diagnositic tests yourself. All you need is a Shop Manual for your year Vette and some basic tools, like a voltage/ohm meter, timing light, 12 volt test light, etc. In fact, the Helms book has a listing of the testing equipment you'd need.

Most of them are pretty inexpensive; even data loggers, like ScanTool or AutoXRay are affordable and can be used over and over again for other problems you're sure to have.

The manual will give you the step by step procedures for tracking down the cause of your miss. Just takes time, patience and the ablility to read, understand and follow the trouble-shooting directions.

Hopefully someone with Opti knowledge will post to help you further.

Jake

 

Thou the coil may not be your problem .the MSD coil you referred to will fit.

 

How do you test coils and modules?

 

How bad does driveability suffer if the module is bad, and do they fade out slowly or just go bang and die?

 

I took my LT1 to the top of a hill where it was pitch black out.
I saw the coil arching only at idle .
Replaced the coil and module and miss went away.
Don't use a NAPA moduel!
I installed one in my LT1 94 and it threw a check engine light and the fans would come on .
Installed oil module and light went off.
After 2 modules from NAPA,I bought a GM and no trouble since.