Hesitation up high....

[Andrew B]

Replaced all of my ignition coils about 3 months ago on my Ls v8 and I am starting to notice a miss up high in the rpm range...4500 and up. The plugs were changed too...I used Bosch irridiums and BWD coils...what else can I do?? Where do I start? gas filter,bad plug,etc....Any ideas let me know...Thanks
I have 98000 on it and it is solid and smooth

 

[joegr]

Many have had bad experiences with Bosch plugs. I personally don't have much trust in BWD coils either.

 

[Telco]

A plugged fuel filter can also cause high RPM dropouts, and as it gets more clogged the RPM the problem occurs at will be lower and lower. Seeing as fuel filters should be changed regularly anyway, try it first and see what happens. You can always revisit the ignition afterwards of the problem is still there after changing the filter.

I also tend to agree on Bosch. I stopped using anything Bosch makes about 5-10 years ago.

 

[jjcool00]

I had similar issues and it was a clogged cat.

 

[Andrew B]

miss up high...

Many have had bad experiences with Bosch plugs. I personally don't have much trust in BWD coils either.

Thank you for all you inputs....I'll start with the fuel filter first, pray its not a plugged converter,and what type of coils should I use if they need to be swapped out? I bought the coils at Advance auto since I worked for them when I had the problem. I will change the plugs to NGK or Accel unless you guys use something else...definitely want to use irridium plugs because their spark is hotter than a regular plug.

Thanks Again!
Andy

 

[Telco]

If the fuel filter doesn't get it, take it by an exhaust shop to check the converters before you do another coil and plug swap. It seems that when you are on bad plugs or coils for a period of time that it will kill the converters, and once the converters are bad they can kill new plugs which will then kill the new coils. If the cats check out, change the plugs and wires at that point.

This is not from personal experience, but from what I've read here.