My idle will speed up after a hesitation. It will goto between 1500-2000rpms when in park. Its like a serge, it will dip down and then idle up. Ive cleaned the TPI (throttle body), changed the TPS, Ox. Sensor, Plugs and wires, cap and rotor. and I cant find any vacuum leaks anywhere. All the hoses are in good shape. I put in a new fuel filter. To top it off there isnt a SES light code so im open for new ideas. Thanks

 

how did you look for vacuum leaks? i chased a similar problem for about a month and didn't hear any vacuum leaks. the vacuum guage read within specs for vacuum. i found a vacuum leak this weekend with carb cleaner. fixed it and idles great now. so, just cuz you don't hear a vacuum leak doesn't mean it doesn't exist.

 

How did you use carb cleaner to find the leaks?

 

sprayed all the vacuum lines. i heard it bubble and the engine stumbled a little when i found it. then, to be sure, i played with the hose and heard the idle fluctuate(sp?) a little bit.