I have a 92 Bonne SE with 185000 on it. When I'm cruising down the road, between 2000 and 2400 rpm, I get a wierd vibration (cant tell if it is tranny or engine) almost seems like it running a cylinder short. If I step on the gas and get it above 2500 rpm it will go away, but comes back when gets back below 2500. It is a constant problem, but not 100% all the time. I have put new plugs, wires in it about a year ago. I'm not having any slip in the transmission that I can tell, and when its idling it seems to idle ok. It just happens between 2000 - 2400 rpm. Any ideas?

A fresh set of plugs and wires certainly won't hurt you. I recommend starting there.

Also, how old is your fuel filter? I had an old N-Body Cutlass that used to do the same thing. All that it ended up being was the fuel filter (engine was being starved of fuel). The Cutlass was so bad that the car would actually lurch when accelerating! LOL.

I'm assuming it happens at any speed and not just highway speeds?

If it were only highway I'd wonder about the lockup on the torque converter. But doubtful.

I had a 93' 88 with the same problem. I changed plugs, wires, fuel filter, oxygen sensor, and two coil packs. Its my dad'* know and still runs the same. I'd venture to say you're engine has carbon build up. Does it destroy oil in 1500 miles?

TCC shudder. Tranny related. Had a fluid and filter change recently?

Sounds like a typical ignition problem to me. I suggest you pull all 6 plugs and inspect them. I'd bet you have one or two fouled. If so, replace them and at least check the wires for resistance.

I'd only suspect TCC shudder if it'* happening with the lockup on the highway....right? It doesn't lockup unless in high gear right?

I said shudder because a while back I had the same problem, fixed it with plugs. It reappeared some time later not as bad, but new plugs didn't fix it, nor did coils, ICM or wires. It lessened when I topped off the tranny fluid. Still hasn't gone away. It only does it when accelerating in midrange with certain throttle angles.

Tranny fluid change is next on my list. Its funny that you say shudder at certain throttle angles, that seems to be right on. However it really only happens at 2000-2400 rpm, mostly on highway speeds but has happened at lower speeds but again same rpm position. If I step on the gas when it happens and throttle above 2500 it will disappear. I was thinking about changing the coils (havent done yet).

The oil pressure is good, doesn't burn or lose any oil. The plugs (oem delco'*), wires (aftermarket, NAPA), O2 sensor (oem delco) all done about a year ago. The fuel filter was done last oil change 3000 mi ago.