I Have a 1995 with a 3.9 that runs great. Here lately however when I let off the gas sharply like when coming up to a stop sign, the engine dies or stumbles. RPM drops to 300 or so before bouncing back to 900. I have replace spark plugs, cap and rotor along with a sea foam injection cleaning. Still stumbles but doesn't die. 75k on the clock. Plug wires look newish. I am going to run another tank of gas through to see if may be I got a bad tank. Any other thoughts would be appreciated. Thanks.

 

Maybe EGR?