All new AC Delco wires and ngk tr-55 plugs are done. The old wires were shot but guess what it still runs like crap or so I thought. After the car sat over night when I left for work this morn it ran almost perfect. The longer I drove it however the miss slowly returned. So it seems to be heat related, does this sound like a ICM or coil issue?

 

scann it again and see if the code is still showing. when failing both the coil and ingnition control mod will sometimes go wack as it warms.

 

my car was doin something similar, it would miss and sputter really bad below 2500, did plugs and wires, drove great for about 2 miles then it was back to how it was, so i just sucked it up and replaced the opti and now shes a champ, you say your opti is only two years old, well if it was replaced with a ebay one or a checker knock off then thats what im pointing my finger at, you need to replace them with the delco unit that runs almost 400 bucks, and if they didnt replace the water pump seal drive shaft thing under the opti with your car having over 100k miles ill bet it leaking some water onto your opti, but thats just my guess

 

I agree, I put a new coil in and did the icm mod and same results, drives great for about 5 min and then slowly the miss comes back. Now the opti was a gm performance one but today I did smell coolant and found a spot right about where the water pump/opti would be, soooooo it looks like a pump and opti are next.

 

amen, and good luck to ya

 

or, a cap and rotor may have been all that was replaced or you may find oil from a leaky seal, or coolant from the waterpump has caused the early demise.


May I suggest replacing the seals while you are in the front. Since you don't know with 100% certainty what exactly "rebuilt motor" means it would be prudent to replace the seals.

 

I know it has to be done but I only drive 10 min to work and it runs great for 75% of that drive! lol o well next weekend. Has anyone heard anything about the Summit Opti?

 

I had one until my 3 month old waterpump leaked all over it.

thepartsladi on ebay can supply you a Delphi unit for the same price


I'd try a Summit unit if I ever kill my opti again.

you'll hear from folks that will tell you to get an MSD but think about it, an origianl unit lasted about 100k miles. manufacturing is actually better now than in the early 90's so I'm confident that you would see another 100k on a summit, accel, jegs or delphi unit. $250 is a fair price

 

gm/ac performance opti is the way to go.

 

Are there any good tricks when doing an opti to help seal it better? Right now I do have a coolant leak but I can't find it to dave my life.