First step - have the check engine light or stored fault codes scanned - for free - at any local auto parts store; Advance Auto, Auto Zone, NAPA. Then, post a reply as 'add answer' with the specific fault code for more assistance.

Possible Causes of Engine Hesitation or Stumble:

Dirty fuel injectors (cleaning the injectors often fixes this)
Dirty air filter (change filter)
Dirty / clogged fuel filter (change filter)
Bad MAP (manifold absolute pressure) sensor
Bad TPS (throttle position) sensor
Bad or dirty MAF (mass airflow) sensor
Low fuel pressure (leaky fuel pressure regulator or weak fuel pump)
Vacuum leaks (intake manifold, vacuum hoses, throttle body, EGR valve)
Bad gasoline (fuel contaminated with water or too much alcohol)

Sometimes, what feels like a hesitation is actually ignition misfire rather than lean misfire. The causes of ignition misfire may include:

Dirty or worn spark plugs
Bad plug wires
Weak ignition coil
Wet plug wires

Yes cats have precious metals inside them, thus they should be paying for this as a scrap rebate or refund, First just change the front Oxygen sensor since this can throw a PO420 code. http://www.autopartswarehouse.com/ Pick the OEM one with the correct connector for ease of installation for a DIY

Some vehicles use an Idle Speed Control (ISC) valve while others use an Air Valve (AV) or Idle Air Control (IAC) valve to control throttle body by-pass air flow.

See this Idle Air Control Valve
For your 1994 Toyota Camry 2.2L EFI DOHC 4cyl
http://www.autozone.com/.../N-j18aeZ9gsof

Use it as a reference to identify the location.The valve is located on the side of the throttle body.

Try the many on-line auto parts sources, such as - www.RockAuto.com, www.autopartswarehouse.com, www.partsgeek.com, to list only a few. For example, they (Rock Auto) list the idle air control valve (IAC) from around $166.00 for your vehicle.

Replace the crankshaft position sensor located on the pass side front of engine. probability nearly 100%.

First step - have the check engine light or stored fault codes scanned - for free - at any local auto parts store; Advance Auto, Auto Zone, NAPA. Then, post a reply as 'add answer' with the specific fault code for more assistance.

Here are some answers for the fault code P0305 and P0306;

P0305 - Cylinder 5 Misfire Detected
P0306 - Cylinder 6 Misfire Detected

Possible Causes:

Vacuum leak
Defective fuel injector
Defective ignition coil pack
Insufficient compression
Defective high tension wire or spark plug

Possible Solutions:

Repair vacuum leak
Replace defective injector
Replace defective ignition coil pack
Replace burnt exhaust valve
Replace defective high tension wire or spark plug

similar problem which is preventing passing a smog inspection. we have done the check list, and now are hunting thru wiring to computer. could it be the computer? how to test that?

Even though the check engine light is not on that does not mean that no codes are stored. Plug in a code reader and see what is there for codes. if no codes are there after you check, tell us that. Try cleaning the mass air flow sensor with aerosol MAF sensor cleaner.

Got the ol' 1.5 Litre eh., had the same problems. Well let's see Eddie. I checked the spark plugs, changed out the O2 sensor on the exhaust manifold, the fuel pump( it's mechanical), changed the entire distributor, cap and wires, checked the timing(3 degrees BTC). gave the caburator the once over because it was flooding. Removed EGR valve and cleaned it out (it was plugged up with carbon). It started to lose power (especially up hills and on acceleration) three days later it would not idle. By then it was very dificult to start, when it did, it would not idle. This was due to valve seal failure. the seals start to leak, when the engine is turned off, engine oil leaks past the seals into the cylinders. Carbon builds up at the end of the valves and the result is low compression because the valve seats have carbon buildup on the seats. I know it's lots of work but it will save you some

Here's a followup to my answere to your problem. The engine oil runs to the cylinders after the engine is shut off. The oil cooks around and directly on the valve seats. The cylinder is unable to hold compression because the valves can't seal due of the carbon buildup on the valve seats. This engine is notorious for this type of problem. I hope this solves your problem sir. Let us know how it turns out. By the way, I ve got the 1988 tercel DX with the 1.5 Litre engine 4 cylinder. This condition is a bad deal if it only affects just one cylinder, it will not idle. a sure sign of carbon buildup will be a wet plug sir. Maybe two wet plugs, black and wet. Good luck. Please let us know how this works out.

The water pump bearing may be the noise and when the water pump gets bad enough it can cause the timing belt to skip a few teeth and then the engine will not run. So, although not a sure thing because I am here and cannot see or hear it, the details might make sense because they are so related. Cause
and effect. The one detail that would nullify my theory would be if you said that you only hear the noise when the car was actually moving, because when you are stopped and the engine is running, the water pump would still be making noise although maybe not as much as when the engine is being accelerated up to speed.

What would you like to ask?

duplicate posting

duplicate posting

If you are looking for causes, it could be low on oil, worn cam, valves, or a rod knock. Rebuilding or replacing the engine could be the only fix. To confirm the problem, you should take your vehicle to a repair shop for a diagnosis.