I have an '87 Toyota Corolla, automatic transmission, 4 door sedan with 80,000 miles on her. Recently have experienced a power and mpg loss. Top speed going uphill (30% grade) is 35. Recent repairs include replacing the timing belt, fuel/water pumps, flush cooling/transmission systems, and tune up to no avail!!! So what’s left? Could it be the catalytic converter? I do live in the mountains at 9,000 ft.
It’s possible that the catalytic converter is plugged up. That will kill your power especially climbing a hill. It will have to be checked by a qualified mechanic. How was the vehicle running after the timing belt change?
Nothing you listed was a “repair.” It was all maintenance, perhaps with the exception of the fuel pump. Why was the fuel pump replaced? I have to assume that a new fuel filter came along with the new fuel pump.
The next thing to do is have someone who knows how to use a vacuum gauge check it for exhaust blockage.
Compression test. Carburetor overhaul. Replace thermostat.
Things get touchy at 9000 feet.
Is the motor running smoothly? Does it sound normal when running? Power loss to the wheels could occur if the transmission is slipping, or has a torque converter problem.
Mountain driving is stressful for the transmission as well as the motor. If the motor seems ok, then the transmission is suspect. The motor makes the power, and the transmission delivers the power to the drive wheel(s).
Both need to be functioning properly in a low power car like your Corolla in mountains, especially up at 9,000 feet. On a good day you don’t have much power to call on, so the transmission needs to downshift properly and transmit all the power your little motor can produce.
Thanks y’all. Yes it was mostly maintenance in an attempt to fix the loss of power problem. The thermostat was replaced. The new fuel pump and filter was because I think when checking into the whole timing belt replacement cost it was suggested to replace the fuel pump (or was it the water pump)? If not that I did not think the gas was getting into the engine so had it replaced. Am going to start with the vacuum gauge check then the torque converter. Yes the motor sounds fine runs smoothly once it is warmed up. Am going to call a few places and hear what they say … thing is I have to drive 70 miles (1.5 hrs) to get the car looked at.