What next............I've got a 93 SE and the car has now developed a new symptom. While driving along, and I notice that this is seeming to be occurring under acceleration occasionally the car develops a VERY noticeable shudder. If I step down on the gas and the car shifts from OD back into 3rd it will go away or if I lift off the gas just slightly it also will go away. I have felt it in 2nd, 3rd and OD. If I stay on the gas and don't do anything to the gas pedal, it seems to cycle in and out of shudder. Does it with the A/C on OR off so the A/C is not the cause. I put new plug wires on a couple of years ago but can't remember if I replaced the plugs or not. The car sat for about 5 years before I put it on the road (a year ago) and I just finished replacing the A/C compressor and converting it over to R134a.

I'm thinking that it is an ignition problem more than likely and will replace the spark plugs first and dump some injector cleaner in it too. Has anyone had a similar problem? If a coil pack was going bad is it possible that it would only misfire one cylinder or both on the pack? Service engine light is not on so I'm not sure with the OBD 1 will it set any misfire codes and NOT turn on the light?

Sounds a little bit like this. https://www.gmforum.com/electrical-133/tcc-solenoid-switch-284972/

this is kind of funny..My 93 bonneville has the same problem and started wit hreplacing the plugs and it helped none..But i did look at my trans fluid and its pretty nasty so picked up new fluid and a new filter..Have yet to install but i am gong to on wenesday and i will be sure to let you know if it helps

I thought about the torque converter possibility and if the symptom occurs in 2nd, 3rd and OD the TCC shouldn't come into play until it'* in 3rd/OD correct? My tranny fluid is clean.

If a coil pack was causing a misfire, wouldn't it set a code and turn on the light?

Could be a problem with the TC, or possibly the TC is locked. Try that test to see if the TC goes out of lock up.

It should set a code and turn the check engine light on yes

I'll try tomorrow but I think that the converter is working ok. When coming from a dead stop the tachometer changes rpm 4 times. I'll also look to see if it has two switches at the brake pedal and check those if it does.

I also ran it for a while with the shifter in "D" and not "OD" and I had the shudder.

my car does the exact same thing LOL...now im determined to get this figured out for the both of us