Ok, I've got a strange problem. My early '95 Passport is popping during acceleration. It's not consistent, and is strange in that I can feel the pop through the gas pedal. It does it more with the A/C turned on. The RPM also varies slightly when at a constant speed. I haven't seen any obvious intake leaks. I'm planning on driving up to Phoenix to tow a couple motorcycles home and really don't want to drive it that long if this is a serious problem.