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-   -   Shuddering/Struggling engine/tranny HELP!!! (https://www.gmforum.com/1992-1999-91/shuddering-struggling-engine-tranny-help-188298/)

Burgundy_Boat 04-21-2003 11:11 PM

Shuddering/Struggling engine/tranny HELP!!!
 
ok, tonight I was driving my bonnie, all of a sudden the engine started to struggle at low RPM (up until 3000 or so) and then it would rev fine, but before that it was kinda like a cylinder was not firing or something and there was a noticeable drop in the exhaust note. this problem was most noticeable when you floored it when the engine was at idle in neutral, although it did not matter if the car was in gear or not
after i parked the car i popped the hood, one spark plug boot was higher than the rest at the coil pack, pushed that down (it snapped down), didn't seem to make a difference. also there car was hemorrhaging some type of fluid quickly, i didn't notice it after the engine had cooled though

my mom came over to me and i took her bonnie (also a '95 SE) and she took mine to the garage with her boyfriend following her in his bonnie ('96 SSEi) she said that it was shuddering like crazy in 2nd gear and when going about 60 MPH in lock-up, when she let off the gas and then got back on that it would shudder (i'm thinking that might be the TCC) she thinks that the tranny is totally shot, what do you guys think??

DeathRat 04-22-2003 08:23 AM

The purpose of the Transmission Converter Clutch (TCC) feature is to eliminate the power loss of the torque converter stage when the vehicle is in a cruise mode. The TCC system uses a solenoid operated valve to engage the TCC which couples the engine flywheel to the input shaft of the transmission through the torque converter. This reduces the slippage losses in the converter, which increases fuel economy. Another solenoid (pulse width modulator or PWM solenoid) is used to regulate fluid pressure to the TCC to "cushion" the apply of the clutch.

For the converter clutch to apply, at least two conditions must be met.
1.Internal transmission fluid pressure must be correct.
2.The PCM completes a ground circuit to energize the TCC solenoid in the transmission, which moves a check ball in the fluid line.

The PCM controls the TCC apply solenoid by looking at several sensors.
1.Engine must be in closed loop operation.
2.Vehicle Speed Sensor (VSS). Speed must be above a certain value before the clutch can apply.
3.Coolant Temperature Sensor (CTS). Engine must be warmed up before the clutch can apply.
4.The 4th gear switch is used as a input to the PCM. The PCM uses the switch signal for TCC engage and disengage points.
5.Throttle Position Sensor (TPS). After the converter clutch applies, the PCM uses the information ftom the TPS to release the clutch when the car is accelerating or decelerating at a certain rate.
6.Another switch used in the TCC circuit is a brake switch which opens the 12 volt supply to the TCC solenoid when the brake is depressed.

DeathRat 04-22-2003 08:26 AM

I'm more inclined to think that some of the internal parts are slipping or shot.


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