I just aquired a 1997 Seville SLS from a relative, overall it is in good condition. It currently has 162,000 miles on it. I was told it has a slight miss in the engine when you are at a cruising speed between approx 38-42 miles an hour. So naturally my first response was to get out in it and see what it was doing. I got out on a local roadway that has a speed limit of 40 mph, and bam I felt it. Although in my opinion and from my mechanical experience it felt to me as if it was a type of "Shudder" in the tranny when it was trying to go into overdrive. From reading these posts I'm starting to suspect the TCC Solenoid. I tried driving the vehicle in 3rd rather than Odrive and the shedder went away. So my question is, is there any other way to be sure that it is the TCC and not in the bands of the tranny? And is there the possibility that it is in the fuel delivery system or the ignition system?

Sorry, sorry, sorry. After further research I found this is a 1994 Seville SLS "NOT" a 1997 SORRY!

 

What are the on board diagnostic codes?

 

I just got the vehicle 2 days ago and have been researching the electronics diagnostics system, I'm used to the late 80's early 90's where you hold a combination of buttons on the climate control to display the codes and I haven't figured this one out because my fiance' drives it to work and it's gone most of the time and I haven't purchased the manual for it yet.

 

Look in the FAQ section of this forum.

 

An engine miss will cause what some consider to be a TCC shudder. Once the converter goes into "lock-up", any engine miss/roughness will be amplified, making it seem like the TCC is the problem, when it is not.
If there is an actual problem with the converter, the TCC will only shudder on application, but not after it is fully applied. If the shudder you feel is happening all the time after the trans shifts into 4th gear, it is an engine miss...not a converter issue. The reason you feel it "go away" in 3rd has to do with the engine torque, and gear ratios. In 3rd, there is not as much pressure on the trans gears as there is in 4th, where the trans is overdriving the gear-sets.
We have more problems with converter clutch slippage than a shudder, and that slippage is due to worn seals...not a converter problem. The slippage is more the symptom than the disease...
Check on the OBD codes first, and see what you can find there.