93 SE Shuddering while Driving (fixed)
 

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's 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

I pulled out the Pontiac Service Manual last night and there is actually a section in there about TCC shudder. It said if the shudder occured AFTER it had shifted into TCC, the problem was probably not a transaxle problem and to check plugs, wires, coils and about 10 other things.

Does anyone know if the TCC solenoid is easily accessible from the outside of the transaxle?

I had an 82 Cutlass that had a bad TCC solenoid and it would actually lock the front wheels on the car when it shifted into TCC and you came to an immediate stop. Is there a plug somewhere on the transaxle that I can unplug to see if the problem goes away?

I'm pretty sure I felt the shudder when I had the car in "D" so I'm starting to think this might not be a good sign, unless it is an electrical (ignition) problem. Probably won't get to fiddle with it until tomorrow night either. Wanted to drive this car on a long trip next month and now I'm a little worried.....:bluecry:

Have you checked your motor and trans mounts?

The TCC solenoid is inside the transmission.

No, have not checked the mounts. I know the one by the water pump is good for sure due to my adventures getting that changed.

I did read in the service manual that it would set a code (39) but not turn on the service engine light, so that's another thing I need to check.

Just seems like every week it's something else with this car now and my parents kept it in excellent condition and always had the service work done at the dealer when it needed it.

What RPM are you at? is it variable? I haven't looked at what else you have done, but I would look at something simple like fuel filter, pressure regulator, and clean TB.

Won't get to really look at until this afternoon. It seemed to do it mostly at highway speed when going up a slight incline and the tranny (as far as I can tell) is still in TC lockup and it did not downshift was when it did it the most. I think it did it as well a couple of times when I had the shifter in "D" and not in "OD" which would then use the TCC function (I believe). So if it IS doing it when it's in "D", I've got to assume that it's not the TCC. Will check the plugs, wires and coil packs this afternoon as well.

:thumbup2:thumbup2:thumbup2: PROBLEM SOLVED :thumbup2:thumbup2br2 Stopped at NAPA on the way home and picked up a set of plugs, plug wires and a fuel filter. Installed plugs and wires and what I found was the #6 plug wire metal connector (not the heat shield) was not snapped on to the end of the plug. Checked coil packs and all were 5.91 ohms on the secondary side (post to post).

Took it for a test drive and the TCC is working fine as described in the posts above. No more shudder.

Got home and started checking the plug wires. First three all had good numbers. Fourth wire.....ZERO resistance (plug wire #4), fifth wire good, sixth wire was zero to 8.3 to 12.67 to zero (#6). Two bad wires. Guess they were just good enough to let the car run but once they got a load on them they started to misfire.

See pictures of wires below. On the coil end you can see the gray outer jacket and the white inner jacket, on the plug ends gray outer jacket, charcoal inner jacket. Burnt.

Second picture is of a good wire and you can see both ends are white on the inner jacket.

Oh...those spark plugs I figure are about 6 years old or older. I've driven the car for about a year and it sat for 5 in my driveway with occasional starts.

Not sure pics are on here.......might need some help posting them.

Oh, and on the WHAT'S NEXT:mad::mad:front..............when I pulled in the drive when I got home from work ....the right front tire was half flat!!! Jeez, does it ever end? :confused: :duh: Gap on those plugs...way bigger than .60 and less than .80....

Glad to see you got it fixed i replaced my cars plugs just not its wires or filter yet those were next i will mark this thread as fixed!

my car did that too. figured it was the TCC, but then it stopped moving all together. filter in the trans was hooped, looked stock with 300,000 kms on it. gonna see if it moves tomorrow !

I had the same problem with my '87 Olds 88, When I picked it up it ran a little rough but made the 200 mile trip home ok. Then it would hardly run, I posted it up on a GB American car forum and was told to get it scanned, replace the coil packs, my ecm was shot and the sensors had gone bad. I put new plugs & wires in and that fixed the problem immediately. I always treat any car I buy to a full service and checkover anyway so no extra expense was involved.
Always check the easiest fix first before you start throwing money at the car.
Thanks for letting us know what you found and fixed the problem.
Roger.

Had the Same issue on my 92 Bonneville. Replaced the Fuel Filter (Loooong overdue)...when I pulled the filter out, the gas in it was Brown!!! (Sure sign there)

So it now has a New filter courtesy of Autozone and a small bottle of Lucas Fuel Treatment in the gas tank...after about 10 or so miles of driving the shudder is almost unnoticeable. Next on my list is the PCV Valve.