My 1995 3.4 v6 with 238xxx miles will have a high idle around 1200rpm when I start it up, and will slowly go down to 750 as it warms up. If I engage it into reverse or drive it will drop down to 1000/1100 rpm and still idle high well everything warms up. If it is a cold day the exhaust will be white, but I haven't noticed white exhaust with the warmer weather. When everything is warmed my truck runs like a watch. Would there be white exhaust on a warm day if it was a blown head gasket?
I'll post some videos and compression test results soon. Other revelant things, I've recently cleaned maf/throttle body/plugs/air filter.