Hello,
Can someone out there tell me if they have had this problem with there V6-(2.8L mpfi)..The engine idles at fast idle after start up then gradually decreases in RPM-(normal);then , around 500rpm to 800rpm ,the engine begins to rise and then lower speed and sometimes it seems like it wants to stall.When the accelerator is depressed quickly,the engine rpm drops alot then picks up(it isn't a quik throttle response).Spar plugs were changed,distributor cap and rotor next,then fuel filter.
Can someone direct me in the right direction?
Thanks guys!!!

 

Check the timing.

 

if you didnt change spark plugs in that scene as well then I'd suggest looking at that as well.... my car did the same when it needed a new O2 sensor also...

check your TPS and IAC, there's a tech article on it, you can find them from the main page.

 

also check and make sure everything on the dizzy is working properly.