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I'm new to Toyota. Was given a '92 Camry 2.2 auto with 130K miles. Car received little maintenance and ran like poop. I have replaced the original plugs, cap, rotor, wires, and PCV valve. Changed the oil and had the trans fluid flushed. I removed the throttle body and cleaned it with a tooth brush and MAF cleaner. All vacuum lines appear OK. I ran a double dose of fuel injector cleaner thru the first two tanks of gas. The car runs 90% better with the throttle body cleaning seeming to make the most improvement.
The car is very sluggish when accelerating from lower RPMs, anything under about 2500. Once it starts to rev, it feels very strong and smooth and revs freely.
Finally, to my question. It seems when the car is stone cold, the first few times I take off, it feels much stronger. As soon as the temp starts coming up it gets sluggish down low. It almost feels like it's too lean. Any theories on what might be wrong? Also I average 22 mpg in mixed driving so far. Does that sound about right?
Thanks in advance for any suggestions.
 

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Compression check

Can you do a compression check on the cylinders? If the previous owner didn't change the oil regularly, it could be that the cylinder walls and rings have some wear, and the cylinder compression is not up to specification.
As the engine warms up, the cylinders will actually expand a little and compression will decrease, causing a drop in combustion efficiency.

If you have a compression gauge, test initially with just the engine warmed up. Then, add a little engine oil to each cylinder as you recheck each cylinder.

Be sure and record all your pressure gauge readings, for each cylinder.
This will help with your final analysis and decisions.

The oil added/wet test will give you an idea as to whether the rings and cylinder walls are responsible for your compression test result. This is opposed to the cylinder pressure leaking through the valves at the top of the cylinder.
 

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The computer(ECU) runs the engine using preset "rich" settings when engine is cold, this is "Choke mode", O2 sensors are not used, this is also called Open Loop.
When engine warms up ECU switches to Closed Loop and uses O2 sensor and other sensors to calculate the fuel/air mix.
In Open Loop the ECU also advances the timing, so checking the spark timing when engine is warmed up would be a good idea.
The sensor that tells the ECU to switch from Open Loop to Closed Loop is called the ECT(engine coolant temp) sensor, this is a 2 wire sensor that reports the coolant temp to the ECU.
There is a separate 1 wire sender, that is used for the dash board temp gauge

Closed Loop fuel/air mix sensors:
Air Temp sensor, on the air filter housing.
O2 sensor, on the exhaust manifold down pipe.
MAP sensor, on the firewall behind the throttle body.

Air temp sensor is used because cooler air is denser than warmer air so requires a richer mix, this is why people say there car feels like it has more power in the colder winter months.......it does because of the richer mix, also MPG goes down.

O2 sensors use a chemical reaction to determine the oxygen content in the exhaust.
These do wear out, 70k-100k miles is the recommended life span, burning oil or overly rich running can foul them much earlier.
The ECU checks the O2 sensors all the time but they can pass the test and still be marginal, they tend to fail "lean" so cause the ECU to run the engine richer than it should be run.
The rear O2 sensor, behind the Cat converter, is there to test the Cat Converter, the ECU compares this O2 sensors reading with the "upstream" O2 sensor(s).
So the rear O2 sensor plays only a small part in the fuel/air mix the ECU uses, and it will usually last twice as long as the "upstream" sensor because the Cat protects it from most contaminants.

MAP(manifold absolute pressure) sensor tells the ECU the air pressure in the manifold, this tells the ECU the air pressure outside, sea level or mountains, and also the Load on the engine(throttle position).
These rarely fail, but do rely on a vacuum line connected to the intake manifold, and this line does crack and leak so pressure being reported to ECU is not correct.


There is also the TPS(throttle position sensor), on the throttle body, tells the ECU where your foot is on the gas pedal, this is a simple variable resistor, like a light dimmer or volume control, the ECU sends it 5volts and TPS returns 1volt at closed throttle and up to 5volts at wide open throttle, so return voltage tells ECU throttle position.


And as always getting any OBD I codes from the ECU can be helpful, the ECU is always storing codes, these don't all turn on the CEL(check engine light), they are there to troubleshoot any problems from marginal issues.
 

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The computer(ECU) runs the engine using preset "rich" settings when engine is cold, this is "Choke mode", O2 sensors are not used, this is also called Open Loop.
When engine warms up ECU switches to Closed Loop and uses O2 sensor and other sensors to calculate the fuel/air mix.
In Open Loop the ECU also advances the timing, so checking the spark timing when engine is warmed up would be a good idea.
The sensor that tells the ECU to switch from Open Loop to Closed Loop is called the ECT(engine coolant temp) sensor, this is a 2 wire sensor that reports the coolant temp to the ECU.
There is a separate 1 wire sender, that is used for the dash board temp gauge

Closed Loop fuel/air mix sensors:
Air Temp sensor, on the air filter housing.
O2 sensor, on the exhaust manifold down pipe.
MAP sensor, on the firewall behind the throttle body.

Air temp sensor is used because cooler air is denser than warmer air so requires a richer mix, this is why people say there car feels like it has more power in the colder winter months.......it does because of the richer mix, also MPG goes down.

O2 sensors use a chemical reaction to determine the oxygen content in the exhaust.
These do wear out, 70k-100k miles is the recommended life span, burning oil or overly rich running can foul them much earlier.
The ECU checks the O2 sensors all the time but they can pass the test and still be marginal, they tend to fail "lean" so cause the ECU to run the engine richer than it should be run.
The rear O2 sensor, behind the Cat converter, is there to test the Cat Converter, the ECU compares this O2 sensors reading with the "upstream" O2 sensor(s).
So the rear O2 sensor plays only a small part in the fuel/air mix the ECU uses, and it will usually last twice as long as the "upstream" sensor because the Cat protects it from most contaminants.

MAP(manifold absolute pressure) sensor tells the ECU the air pressure in the manifold, this tells the ECU the air pressure outside, sea level or mountains, and also the Load on the engine(throttle position).
These rarely fail, but do rely on a vacuum line connected to the intake manifold, and this line does crack and leak so pressure being reported to ECU is not correct.


There is also the TPS(throttle position sensor), on the throttle body, tells the ECU where your foot is on the gas pedal, this is a simple variable resistor, like a light dimmer or volume control, the ECU sends it 5volts and TPS returns 1volt at closed throttle and up to 5volts at wide open throttle, so return voltage tells ECU throttle position.


And as always getting any OBD I codes from the ECU can be helpful, the ECU is always storing codes, these don't all turn on the CEL(check engine light), they are there to troubleshoot any problems from marginal issues.
Tank you, very good
 

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Do all that was suggested, but remember if you drive something else, more up to date, then the Camry will feel more of a slug. We have a new GDI 2.4L of another brand and if I drive the new(er) car then drive the Camry, it feels like the engine is baffed. I've maintained all that has been suggested but the engine is just old technology - which will probably out last the new car.
 

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Yeah, these engines are just slow. I had gotten used to it, but my friend lent me his 2014 ES350 last summer, and when I went back to driving the Camry, it felt very sluggish.

I try to keep track of gas mileage and I've had tanks as low as 20-21mpg and also as high as 25-26 (but mainly if highway drives). I usually get around 22-23ish. I think that fuel economy might be about right.
 
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