Problem with Toyota Corolla 94

[calettso]

I have been having 2 problems with my 94 Toyota Corolla (150k miles) for the last 2 months. No check engine light or warnings from the car. It is to old to get a reading from Autozone/Pepboys.
Note: This car was not bought in California and does not meet California emissions standards.

Problem (1) Description: When the car has warmed up (only when warm) and I am stopped and in drive or Reverse, the car idles rough and OCCASIONALLY stall if I do not shift it into Neutral or Park. This problem intensify if I am running the A/C

Attempt #1 to fix:Changed the air filter
Result: No Change

Attempt #2 to fix: Bought a can of carb cleaner and sprayed some in the throttle body port that leads to the IAC (idle air control) valve
Result: Minor Improvement but problem remains

Attempt #3 to fix: Cleaned around the throttle body plate and cleaned a bit past the plate with a soft tooth brush
Result: Minor Improvement but problem remains

Problem (2) Description: I noticed it around this time. It felt like a lost of power as I am driving. It usually occurs when accelerating up small hills mostly. Also Problem 1 become more noticeable.

Attempt #4 to fix: Added some STP fuel injector cleaner for the first time in years. I probably only did this one time before over 5 years ago.
Result: Maybe coincidental but problem 2 intensified and problem 1 remains.

Attempt #4: Installed a new throttle body position sensor (TPS) according to the Haynes manual and I adjusted it to get the correct resistance when properly installed.
Result: Minor Improvement but the problems remains

Attempt #5: Bought and installed a new Oxygen sensor because the previous one indicated a lower voltage drop across it than what the Haynes manual described.
Result: Minor Improvement but the problems remains

Attempt #6: I checked the RPMs both when in park/neutral and when initially changed to drive or reverse. According to the Haynes manual the car idled to low so I adjusted the idle to match the data found in the
Result: The car no longer stalls in drive but both problems still remain

Attempt #7: I checked the spark plugs. Plug #1 (closet to oil cap) well has oil in it. However no oil is touching either tip/ends of the spark plugs. The oil is on the well wall and the thread of the spark plug. I cleaned the oil off and reinstalled and check the following day. No noticeable oil.
Result: Both problems seem to decrease significantly. However, the following day significant problems. After a long drive problems 1 & 2 are back and worst. As I am about home and off the interstate I notice serious power lost during acceleration. There is smoke (white) coming from under the hood just as I am about to pull into the parking lot and the car is shaking in a rhythmic patter in drive, park, neutral . It was too dark to do anything so I let it sit overnight.

I start the car up in the morning and the rhythmic pattern is still there. So I suspect the spark plug and oil issue maybe back.

Attempt #8: I checked the spark plugs. Plug #1 (closet to oil cap) well has oil in it. Still no oil is touching either tip/ends of the spark plugs. The oil is on the well wall and the thread of the spark plug. So I cleaned it out again.
Result: The rhythmic pattern is still there. So I suspect the catalytic converter. I figured it is blocked and there is a great amount of pressure built up between it and the engine

Attempt #9: Temporarily removed the oxygen sensor to relieve the pressure and check to see if it is the cat converter that is the problem.
Result: The rhythmic pattern goes away but there is still a loss of power going up hills.

Any suggestions as to what my problem(s) is/are and how to fix it/them? Help!!!!!!!

[BlownHeadGasket]

I had some similar issues with my 1990 corolla wagon that almost completely eliminated with a new PCV valve (about $4 and 1 minute to install).

Sometimes these symptons can also be the result of a worn timing belt (rough idle is common) since the car won't fire properly. This might be what you need to do. Check the engine for a sticker near the valve cover or belt cover that says when the belt was last changed.

Good luck.

[cipher93]

In all this, you never replaced the plug wires, distributor cap, and rotor? Next step after that is to check for vacuum leaks. I had an issue with erratic idle and an O2 sensor fixed it, but that was only after changing plug wires, plugs, and cap/rotor. Next step would be the vacuum lines leaking.

[speedy25]

Doh! Replace your spark plug well seals on the valve cover!

They get hard as a rock and dont seal anymore. Thats why you have oil in the spark plug wells. Oil cooled spark plugs are BAD!

I dont have a manual to check the IAC, but I'm sure if you remove it and THEN do your cleaning you will get your proper idle back.

If you have any doubts about your engines internal integrity, do a leakdown test to see if rings and valves are OK.

-SP

[Rip The E Brake]

Originally Posted by speedy25

Doh! Replace your spark plug well seals on the valve cover!

They get hard as a rock and dont seal anymore. Thats why you have oil in the spark plug wells. Oil cooled spark plugs are BAD!

I dont have a manual to check the IAC, but I'm sure if you remove it and THEN do your cleaning you will get your proper idle back.

If you have any doubts about your engines internal integrity, do a leakdown test to see if rings and valves are OK.

-SP

Speedy... WINNER

[tonyhawk]

The problem I have with it right now has to do with the Engine cooling system. I had notice that the temperature gauge needle was not in the normal position. It had gone to the red area. What I have done in an attempt to remedy the problem was to check the toyota corolla repair manual and replace the thermostat and added additional antifreeze to the radiator. However, the problem did not go away.

[94PrizmDD]

Do a pressure test on the cooling system. My dads civic used to overheat and we replaced his radiator and problem solved.

[speedy25]

First you have to confirm that the thermostat opens and closes properly. Boil it in water to find out.

If the thermostat IS ok the next part to repalce is the radiator.

In fluke cases the water pump impeller has failed or stere is still air in the cooling system.

-SP