Can't get my car to misfire

[JaredLS]

That's probably a good thing most of the time, but my issue is a bit different. About 2 weeks ago I noticed a hesitation when trying to accelerate, a little bit later while under hard acceleration I got a blinky CEL and pretty good vibration. (I was thinking, okay great, 4th coil needs to be replaced). I drive it home and park it. I decided that this time I'm going to change it myself. I ordered two coils online (not from Global but the other ebay guy mentioned here). I started the car up next day- no CEL -tried to get a code- can't. I decided to drive it- drove it for a week in 4th(b/c I heard it would put less stress on the coil- good mpg ) until I had a day off, so all went well no CEL. Last few days- when I could work on it- I've been putting it under some high rpms 3k 4K. The acceleration isn't as good but still no CEL. This sucks cause now I have to hope it doesn't decide to go bad until the weekend.
Any ideas? Has this happened to anyone else? Or was my CEL a fluke?

 

[TicTacTone]

did you test any of your coils before assuming that was the problem? i dont know a whole lot about the ls but in general you should ohm your coil before replacing it to make sure thats the problem.

 

[joegr]

did you test any of your coils before assuming that was the problem? i dont know a whole lot about the ls but in general you should ohm your coil before replacing it to make sure thats the problem.

Bad advice. That won't do any good with the kind of coil failures that the LS has. They have to be stress tested. There's even a TSB on this.

 

[cwhorley]

How do you stress test the coils? Is there someone to take the coils to for testing or is this something we can do ourselves?

 

[joegr]

How do you stress test the coils? Is there someone to take the coils to for testing or is this something we can do ourselves?

It takes special equipment.
Dealers can do it, but it would probably be cheaper to just replace them, if you are doing it yourself.

 

[cwhorley]

It takes special equipment.
Dealers can do it, but it would probably be cheaper to just replace them, if you are doing it yourself.

OK. I just bought a set of 8 and I'm planning on installing them all and keeping the current ones that aren't bad for the future. I just thought it would be nice to test and make sure that was the problem to begin with.

 

[97stscaddy]

Even if the CEL goes away it still stores a code in the PCM which can be read at ANY time afterwards.