Most likely a vacuum leak. Spray carburetor cleaner on vacuum lines and fittings, and where the intake manifold meets the head to locate the leak so it can be fixed.
Dec 10, 2011 at 11:40 PM
RASMATAZ
CAR REPAIR CONTRIBUTOR
75,992 POSTS
When you hit the leak it will react and smooths out, if your hearing is no good-use a vacuum gauge
Dec 10, 2011 at 11:50 PM
ROGERTHOMPSON08
MEMBER
2 POSTS
well i guesss at some point in its life it could have been overheated to cause something like that,i thought it surely was some kind of sencor like a TPS or something
Dec 10, 2011 at 11:52 PM
RASMATAZ
CAR REPAIR CONTRIBUTOR
75,992 POSTS
The IACV and TPS do weird things too, to include fuel pressure problem
Dec 11, 2011 at 12:18 AM
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.