either the od is burnt out and needs to be replaced or the plastic grommet under the throttle plate is bad. this grommet connects your tv cable to your throttle linkage. the last alternative is that the hard bar(input shaft) is broken. if that is the case, then it will shift from 1-3rd and when it tries od, it feels like its going into neutral
dirty trans fluid might be the cause. have it changed, but not flushd
This can be caused by many things. Your best bet is to take it to a transmission specialist and have him determine the cause. It may be as simple as a solenoid that has gone bad or it might be more serious.
Mona Lisa Overdrive was created in 1988.
remove the shift knob,t bar, shifter boot and plate, the switch is attached with 2 screws
If a 1988 Mercury Grand Marquis shifting out of second gear gets choppy after acceleration then the overdrive band may need servicing. An overdrive band that is sticking can also cause this problem.
It's the overdrive engage button, which is like a 5th gear. It only engages when the gear lever is in 4th gear and it can be operated without depressing the clutch.
14 mpg
Purchase a 1988 standard shift 2.5 for parts then swap all the parts over.
not downshifting.
physically it will fit but the wire harness and computer are not compatible.
They are compatible. the only problem you may have is the shifter. If the corvette does not have overdrive on the shifter you won't be able to get the car in first gear.
Vacuum on an automatic transmission normally controls shift timing and would not effect downshifting (normally). Shifting is normally caused by internal fluid pressure in the valve body, with WOT control to over-ride shift points. Check the shift cable and make sure it is properly adjusted, if that is not it then the problem is internal to the valve body of the transmission.