well i pulled up into the carwash today and put it in park. let it idle but the RPM's were fluctuating from 400-800 and a couple times started to shake and almost died. any ideas? i also have a miss at idle and still cant figure it out. still no codes but doesn't do it under load. any ideas? appreciate it!

 

Anyone??

 

what motor do u have

 

5.3 liter

 

Did it just start this out of the blue or did you change something?

 

out of the blue. i did fix my miss at idle though, it was the cheap *** ZEX s/c spark plugs i bought. put the original AC Delco's in and runs like a champ w/ a SMOOTH idle and no misfiring. yeah!

 

Put some NGK TR6's in, the stock plugs are too hot and can make your engine prone to detonate. They are cheap too like 1-2 bux each.