85 Shifting Issue
85CollEdition
01-28-2008, 03:13 PM
Hi all,
I was wondering if anyone has heard of the problem that I am having with my 1985 Buick Lesabre Collector's Edition.
When I drive the car under normal acceleration, the car shifts all the way to overdrive by the time I hit 30mph. The other thing that she does is that she does not like to down shift when slowing down to a stop unless you go very slow to stop. It acts like a standard does when you don't push the clutch in. She also doesn't seem to have the power that she should have. This does not always happen and it doesn't seem to matter if she is cold or hot. It has the 5.0 V8 in it. I'm not sure what transmission I have. I have checked the TV cable and it is just fine. I'm not sure what else could be causing this issue. Any help or suggestions would be greatly appreciated.
I was wondering if anyone has heard of the problem that I am having with my 1985 Buick Lesabre Collector's Edition.
When I drive the car under normal acceleration, the car shifts all the way to overdrive by the time I hit 30mph. The other thing that she does is that she does not like to down shift when slowing down to a stop unless you go very slow to stop. It acts like a standard does when you don't push the clutch in. She also doesn't seem to have the power that she should have. This does not always happen and it doesn't seem to matter if she is cold or hot. It has the 5.0 V8 in it. I'm not sure what transmission I have. I have checked the TV cable and it is just fine. I'm not sure what else could be causing this issue. Any help or suggestions would be greatly appreciated.
Blue Bowtie
01-28-2008, 08:26 PM
Welcome Aboard!
The torque converter clutch (TCC) solenoid could be sticking. Sometimes a clean filter and fresh load of transmission oil will clean up the hydraulics and restore normal operation. Sometimes, it won't.
There is a relatively easy way to test this theory. Unplug the TCC connector from the transmission ( a four wire connector) and test drive it. The TCC will not engage, and therefore should not remain engaged as you decelerate. If the engine doesn't exhibit the stalling tendency, the TCC may be the reason.
Another possible cause is that the Throttle Position Sensor (TPS) is improperly adjusted, and is not allowing the ECM to read the correct throttle angle. If the TPS voltage at idle is over 0.61VC, the TCC may not release when the throttle is closed.
I'm guessing that the engine is carbureted with an E4ME Rochester, given the year and engine type. Inexperienced mechanics can attempt to adjust idle without adjusting the TPS voltage, resulting in this situation.
The torque converter clutch (TCC) solenoid could be sticking. Sometimes a clean filter and fresh load of transmission oil will clean up the hydraulics and restore normal operation. Sometimes, it won't.
There is a relatively easy way to test this theory. Unplug the TCC connector from the transmission ( a four wire connector) and test drive it. The TCC will not engage, and therefore should not remain engaged as you decelerate. If the engine doesn't exhibit the stalling tendency, the TCC may be the reason.
Another possible cause is that the Throttle Position Sensor (TPS) is improperly adjusted, and is not allowing the ECM to read the correct throttle angle. If the TPS voltage at idle is over 0.61VC, the TCC may not release when the throttle is closed.
I'm guessing that the engine is carbureted with an E4ME Rochester, given the year and engine type. Inexperienced mechanics can attempt to adjust idle without adjusting the TPS voltage, resulting in this situation.
85CollEdition
01-29-2008, 10:29 AM
Thank you very much for the info. I will try the suggestions out and let you know if it worked. :bigthumb:
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