I've got a 1996 Chevy Blazer 4WD and recently one of my buddies told me about how much different his car ran with new spark plugs and that made me wonder if I should replace mine. The thing is, there is no service records involving the spark plugs besides them being inspected and put back in stating, "They did not need to be replaced.". So I don't know if they've ever been changed once. The car has about 250,000 miles on it so I decided that I would take up the project of replacing them even though the only thing wrong with the car is a slightly rough idle (barely noticeable). So I'm looking on the Blazer forum and I see all these post about different wireset's and different Spark plugs.
I want to use AC Delco Spark plugs are the 41-993 still recommended? I see many people talking about "Platinum" ones, and if the 41-993's are recommended are they pre-gaped for the 4.3, If not what gap should they be?
I also plan to replace these parts do they look good or would you recommend something else? (I'm aware of the bracket on the ignition coil that's the reason I want it)

CHEVROLET IGNITION COIL DR49 WITH IGNITION MODULE D577 GMC ISUZU

Let me know if you guys think these are alright or if you would recommend something else! Thanks. (Linked 4 Parts above)

 

I used that exact wire set on my 2002 about 100,000 miles ago.

Why do you want to replace the coil?

George

 

Well the coil in the car has 250,000 miles on it and someone on mechanic advice recommended it be changed saying "put a new one in and watch it at night" So I assumed either way mine is probably worn out so might as well replace it.

 

Do what you feel is right after getting some advice but I don't like replacing parts that have not failed unless I cannot solve an intermittent issue because I can't catch it in the act. Then you have to make some educated guesses based on symptoms. Replacement parts can introduce problems that you don't now have. Look for 1" of strong blue spark at a plug end for indication of proper spark strength. Of course issues can be anywhere along the ignition path. My original ignition coil has over 200,000 miles on it.

George

 

I would not advise replacing the ignition module based upon the experience I had with my '95; tried three aftermarket ones...all failed and left me on the side of the road. Stick with the GM Delco ignition module. Remove it, clean off the back of it, replace the heat sink compound, but it back on.

go with the 41-993 spark plugs...they last, and last, and last.

 

I replaced all six of them with 41-993's today. I've just read your comment but already ordered a module with everything on it from GAM. Just didn't wanna have to deal with grinding out the rivets and somehow getting them back together. If there's someway to get a ACDelco ignition coil and put it on the bracket with the ICM I already have, a guide would be helpful.

 

I've ordered an AC Delco ignition Coil and needed mounting brackets. I'll install them and return the rebuilt module. Better safe than sorry..

 

I took the EGR Valve off and cleaned it up as well. Here's my pull from today's work. Tell me which one you think was #3.

 

Access to #3 plug is a bit of a challenge....plug likely broke upon removal....unless you were having a lot of misfires. Even with the steering shaft disconnected, there is still not a straight shot to that plug....and the ceramic does get brittle over time/temp.

When I was trying the aftermarket ignition modules (IM); not only did they fail in the Blazer, but I got one for a Corvette I had at the time. Same results.....lasted a few weeks, died....stranded in a parking lot. Good thing IMs are easy to change. Got to the point I carried the original Delco one in the vehicle and the torx driver to change it. Although usually had to wait an hour for engine to cool down enough for me to get my hands in there.

Good decision to go with the Delco IM.

 

I use this Snapon tool (S9723) for the #3 spark plug. Its expensive so I waited until I found one used on eBay. Doesn't matter much if they break coming out but you don't want the same thing going in. You still need a U joint socket and being a Yoga instructor would be helpful. Some guys report that moving the shaft is not too bad but I have never tried it.




George