[cougarhunter]

I have a 99 Camry and it's having a hard time with accelerating from a stop. It bogs down when I want to go and I have to push the pedal to the floor to get moving. It also won't rev past 3,500 either. And then when the car gets warmer I can get it up to the redline mark, but it does that sporadically as well. When I push down on the gas all the way while driving over 50mph it will not always rev close to the red line if I push the pedal all the way to the floor.

I recently replaced the EVAP System and the Vacuum Switch because of a check engine light. That went away after replacing those units. And I had a lot of power gain from that. I have new NGK Spark plugs and my spark plug wires are NGK and have over 15,000 miles on them. I have new coils a performance air intake had the timing belt replaced and a new fuel filter.

I'm now up in Utah for right now as well and I've been using the 85 octane gas as well, but I don't think that's a big problem because of the altitude and some of this was occurring at lower elevations that had 87 octane gas.
Any ideas on what it could be?

Thanks!

 

[pee_cup]

Where abouts in Utah are you? I love that place.

My first instinct is to say that the catalytic convertor is clogged. That produces the same symptoms. In the past I have been able to have an exhaust shop unbolt or cut the cat off, inspect it and reinstall it for free. I doubt that your problem would be altitude related, but you might try resetting the ECU (not sure what the procedure is on Toyotas but generally it involved disconnecting the battery for 30-60 minutes.

You might want to take a look at the air filter and see if there are any restrictions in the air filter, you said performance intake so you may not have an airbox anymore but I can tell you that my airbox was full of nuts when I bought it. My next step would be to check the fuel pressure. It may be obvious, but make sure the brakes arent binding ( coast in neutral and see how the car behaves)

Depending on where you are at, I can give you a good recommendation of a shop that would likely check the cat out for free for you.

 

[cougarhunter]

Where abouts in Utah are you? I love that place.

My first instinct is to say that the catalytic convertor is clogged. That produces the same symptoms. In the past I have been able to have an exhaust shop unbolt or cut the cat off, inspect it and reinstall it for free. I doubt that your problem would be altitude related, but you might try resetting the ECU (not sure what the procedure is on Toyotas but generally it involved disconnecting the battery for 30-60 minutes.

You might want to take a look at the air filter and see if there are any restrictions in the air filter, you said performance intake so you may not have an airbox anymore but I can tell you that my airbox was full of nuts when I bought it. My next step would be to check the fuel pressure. It may be obvious, but make sure the brakes arent binding ( coast in neutral and see how the car behaves)

Depending on where you are at, I can give you a good recommendation of a shop that would likely check the cat out for free for you.

It seems to be pumping out exhaust pretty well. This happens sporadically. It is a new filter on it. Looks good. Yes it is a performance air intake so no box. From reading around I saw people talking about the car going into "safe mode" and have something to do with coolant sensors. Just seems funny that on my trip heading to Utah down the Gorge I got 47mpg and stayed around 40 to 37mpg. But now it's down to 31mpg. And I'm having the problem of it not having much power when trying to accelerate from stopped position. That and it won't pop into almost redlining every time I want it to going around 50mph. Or when I need to accelerate from stopped it doesn't always go high rpm when I need it to. I've almost been hit a few times now because it's so slow wanting to get going.

 

[cougarhunter]

Can bad coolant sensors cause bad performance? This is mostly happening when it's hot outside. I read somewhere that if it thinks it's too cold that it will run richer. And being that it's really hot out during the day messes up the performance. If they are going bad can that occur without tripping a Check Engine Light? Can Oxygen Sensors do the same? I figured that the computer is more sensitive with Oxygen Sensors and that if there was a problem it would error out?

 

[cougarhunter]

Where abouts in Utah are you? I love that place.

My first instinct is to say that the catalytic convertor is clogged. That produces the same symptoms. In the past I have been able to have an exhaust shop unbolt or cut the cat off, inspect it and reinstall it for free. I doubt that your problem would be altitude related, but you might try resetting the ECU (not sure what the procedure is on Toyotas but generally it involved disconnecting the battery for 30-60 minutes.

You might want to take a look at the air filter and see if there are any restrictions in the air filter, you said performance intake so you may not have an airbox anymore but I can tell you that my airbox was full of nuts when I bought it. My next step would be to check the fuel pressure. It may be obvious, but make sure the brakes arent binding ( coast in neutral and see how the car behaves)

Depending on where you are at, I can give you a good recommendation of a shop that would likely check the cat out for free for you.

I'm in the Provo Springville areas. Yeah I'd like to know if someone could take it off and check it and put it on for free. They would have to cut it off to look at it and then weld it back on.

So can a bad coolant sensor cause the problems of it not doing good performance wise during hot weather conditions? I have noticed also that sometimes when I start it up cold that it idles erratically then goes away. There are no cracks in any of the hoses and I'm not getting any check engine light. I assume that has to do with the Idle Air Control Valve? The thing looks like a pain to get to to clean.

 

[pee_cup]

I am familiar with that area but never dealt with any shops down there, but im sure one of the smaller exhaust shops wouldn't charge too much/ would do it for free. Does the car drive fine when the engine is cold or does it constantly bog down? A bad CTS or O2 SHOULD trigger a check engine light but might not always do so. Unplug the O2, take a test drive. plug it back in, unplug the coolant temp sensor and take a test drive. Also inspect the wiring for them. The ECU will run open loop with those sensors unplugged and if it drives better with one of them unplugged then that might help you single it out. If unplugging the sensors makes no difference then you are still looking at a clogged cat or possibly some vacuum leaks (dont forget to check the oil cap and dipstick tube as sources of vac. leaks)


I am not sure how the MAP (manifold absolute pressure) sensor works on these cars, I know my car has one, I am used to MAF and VAFM setups so you might look into the symptoms of a bad MAP sensor as well.

 

[cougarhunter]

I am familiar with that area but never dealt with any shops down there, but im sure one of the smaller exhaust shops wouldn't charge too much/ would do it for free. Does the car drive fine when the engine is cold or does it constantly bog down? A bad CTS or O2 SHOULD trigger a check engine light but might not always do so. Unplug the O2, take a test drive. plug it back in, unplug the coolant temp sensor and take a test drive. Also inspect the wiring for them. The ECU will run open loop with those sensors unplugged and if it drives better with one of them unplugged then that might help you single it out. If unplugging the sensors makes no difference then you are still looking at a clogged cat or possibly some vacuum leaks (dont forget to check the oil cap and dipstick tube as sources of vac. leaks)


I am not sure how the MAP (manifold absolute pressure) sensor works on these cars, I know my car has one, I am used to MAF and VAFM setups so you might look into the symptoms of a bad MAP sensor as well.

Hey! Yeah it drives fine when the engine is cold. There are two O2 sensors on this car one up stream and one down stream. The down stream one is really rusty.

I did notice that it was over 95 out here the other day and my car was sitting in the sun and the temp reading showed that it was cold. But eventually moved up into the half way range between hot and cold. Does that seem strange that it was way down at cold?

I also have noticed that it takes more times cranking it over to get it to start when it's hot outside and the engine is cold. Any ideas about that? Let me know if you have any further ideas so that it might help me know what sensors I should be unplugging to test.

Thanks!

 

[cougarhunter]

I am familiar with that area but never dealt with any shops down there, but im sure one of the smaller exhaust shops wouldn't charge too much/ would do it for free. Does the car drive fine when the engine is cold or does it constantly bog down? A bad CTS or O2 SHOULD trigger a check engine light but might not always do so. Unplug the O2, take a test drive. plug it back in, unplug the coolant temp sensor and take a test drive. Also inspect the wiring for them. The ECU will run open loop with those sensors unplugged and if it drives better with one of them unplugged then that might help you single it out. If unplugging the sensors makes no difference then you are still looking at a clogged cat or possibly some vacuum leaks (dont forget to check the oil cap and dipstick tube as sources of vac. leaks)


I am not sure how the MAP (manifold absolute pressure) sensor works on these cars, I know my car has one, I am used to MAF and VAFM setups so you might look into the symptoms of a bad MAP sensor as well.

So I disconnected one of the coolant sensors and tried to start it and it was very hard to start and idled erratically and then would die every time.
So I hooked it back up. Then I disconnected the other coolant sensor (smaller one) and started it up and I had a lot more power then before. And this is in the high heat of the day and the car was sitting cold. So should I replace both coolant sensors then?

 

[Stillrunning]

So should I replace both coolant sensors then?

This might help:
http://www.wonderhowto.com/how-to-test-and-replace-your-cars-coolant-temperature-sensor-267190/

 

[pee_cup]

The hard starting (when the engine is cold) is going to be a coolant temp. sensor issue and not an oxygen sensor issue. With the car warm, unplug the coolant temp sensors one at a time and see which one causes the temperature gauge to fall back to cold. That way you can single out which one is for the gauge and which one affects fuel and timing.


As for the coolant gauge showing cold with a cold engine in 95F weather:

The coolant gauge reads a fairly narrow range of temperatures. I do not know for sure but my guess would be 130F to 230F

The upstream oxygen sensor is the one that matters for performance, the downstream sensor checks the function of the catalytic convertor (assuming it is downstream of the cat)

 

[cougarhunter]

The hard starting (when the engine is cold) is going to be a coolant temp. sensor issue and not an oxygen sensor issue. With the car warm, unplug the coolant temp sensors one at a time and see which one causes the temperature gauge to fall back to cold. That way you can single out which one is for the gauge and which one affects fuel and timing.


As for the coolant gauge showing cold with a cold engine in 95F weather:

The coolant gauge reads a fairly narrow range of temperatures. I do not know for sure but my guess would be 130F to 230F

The upstream oxygen sensor is the one that matters for performance, the downstream sensor checks the function of the catalytic convertor (assuming it is downstream of the cat)

Funny thing is that it was the gauge sensor that I unplugged that made it have more power. Apparently it is called the coolant temp sender. The other one is a coolant sensor. The coolant sensor was the one that I unplugged and the car could barely start and missed and would die every time. I think I'll just replace both of them. They are around $10 each here. And it has over 120,000 miles on it and it has never had those changed before.

 

[cougarhunter]

The hard starting (when the engine is cold) is going to be a coolant temp. sensor issue and not an oxygen sensor issue. With the car warm, unplug the coolant temp sensors one at a time and see which one causes the temperature gauge to fall back to cold. That way you can single out which one is for the gauge and which one affects fuel and timing.


As for the coolant gauge showing cold with a cold engine in 95F weather:

The coolant gauge reads a fairly narrow range of temperatures. I do not know for sure but my guess would be 130F to 230F

The upstream oxygen sensor is the one that matters for performance, the downstream sensor checks the function of the catalytic convertor (assuming it is downstream of the cat)

So I replaced both the coolant sensor and temp sender. I did them one at a time and each one did increase my power when replaced. Now the problem that I'm experiencing after installing the temp sender is my temp gauge is moving around when I'm driving. It will rise about a quarter between hot and the half way mark. It's not hitting the hot zone at all. But it fluctuates while driving. I have noticed that my A/C is colder now because it's switch ties in with the coolant sensors too. Coolant level is full. I checked the radiator and the reservoir and they are full. My guess is the thermostat is partially sticking closed? I just had a timing belt done about 6,000 miles ago and they replaced the thermostat. Or they said they did. It's on the print out of what they did, but you know how that is. I turned the hot air on for a while and squeezed the radiator lines trying to see if I could get any air out of there. I don't see any way of bleeding air out of it. Is there a way to bleed the air out on this vehicle? All in all I think it's either air that's stuck in there. Or a partially stuck closed thermostat.

 

[cougarhunter]

The hard starting (when the engine is cold) is going to be a coolant temp. sensor issue and not an oxygen sensor issue. With the car warm, unplug the coolant temp sensors one at a time and see which one causes the temperature gauge to fall back to cold. That way you can single out which one is for the gauge and which one affects fuel and timing.


As for the coolant gauge showing cold with a cold engine in 95F weather:

The coolant gauge reads a fairly narrow range of temperatures. I do not know for sure but my guess would be 130F to 230F

The upstream oxygen sensor is the one that matters for performance, the downstream sensor checks the function of the catalytic convertor (assuming it is downstream of the cat)

Well I replaced the thermostat. And it never blew any hot air and the temp gauge went all the way up to hot. The temp gauge was in the normal range just sitting there but never blew any hot air. Then the temp gauge went hot when I went up a hill but the air never got warm. There is only one way the thermostat fits in there. And I filled the radiator to the top and filled the reservoir to full. What's odd is that it didn't suck the fluid out of the reservoir. This is driving me nuts. I bought the cheapest one. And in the back of my mind I could hear the words. Are you sure you want to buy the cheapest one. What if it fails. I should of listened to it. I think I bought a bad thermostat? Do any of you agree?

 

[pee_cup]

Yes you most likely have air in the cooling system. Some cars have a bleeder screw, some don't. A good way to avoid having to bleed the system much, if at all, is to have the bleeder screw open (if the car has one), heat slider turned to HOT and have the coolant resirvoir cap open. Fill the radiator and the engine with coolant, then fill the resirvoir. Secure any coolant hoses, close the cap and bleeder screw and start the car. Watch the coolant level as the engine warms up. Once the engine is up to operating temperature, hold the throttle at a fast idle (1500-2000 RPM) as you crack open the bleeder screw. From there you keep cracking it open and closing it as if you were bleeding a brake system until you get a solid stream of coolant flowing out. Check the coolant level and take it for a test drive. Dont forget about having the heater set to HOT since air pockets like to form in the heater core.

If there is no bleeder screw. You should fill the coolant as described above , remembering to turn the heat to hot, then start the car, remove the coolant resirvoir cap, and squeeze the coolant hoses like you have been doing.

For either situation, parking the car on an incline, pointed uphill, will encourage air pockets to leave the heater core.

I do not know whether the Camry has a bleeder screw. I know that it has a drain plug in the block AND in the radiator which to me indicates that they would most likely have a bleeder screw. It will be at the highest point in the cooling system so follow the top coolant hose to the cylinder head and check for a vertical hex head bolt sticking into the flange between the hose and the head.

I would not suspect a new thermostat to be bad, but it IS possible. Bleeding the system is definitely the first step.

BTW: has your bogging problem been resolved since replacing the sensors?

 

[cougarhunter]

Where abouts in Utah are you? I love that place.

My first instinct is to say that the catalytic convertor is clogged. That produces the same symptoms. In the past I have been able to have an exhaust shop unbolt or cut the cat off, inspect it and reinstall it for free. I doubt that your problem would be altitude related, but you might try resetting the ECU (not sure what the procedure is on Toyotas but generally it involved disconnecting the battery for 30-60 minutes.

You might want to take a look at the air filter and see if there are any restrictions in the air filter, you said performance intake so you may not have an airbox anymore but I can tell you that my airbox was full of nuts when I bought it. My next step would be to check the fuel pressure. It may be obvious, but make sure the brakes arent binding ( coast in neutral and see how the car behaves)

Depending on where you are at, I can give you a good recommendation of a shop that would likely check the cat out for free for you.

I'm still having problems when it's hot outside and I start my car up and try to accelerate it bogs down. The rpms will gradually rise over 3,000 rpms when it shifts. I have the pedal to the floor while doing this. I'm lucky that I haven't been ran over because it takes a long time to get up to speed. It has a lot more power when it's cold outside. My brother has a 97 camry four cylinder and I pushed down on the gas pedal and it was stiffer. Had more resistance and took off better than my car when it was hot outside. Does all these things sound like there is a plugged cat? Am I having back pressure and that is why I don't feel as much resistance on the gas pedal when pushing down on it because there isn't as much vacuum in the intake manifold? The cable is fine and throttle plate opens all the way when you push down on it. I've replaced the MAP, both o2 sensors, tps, coolant sensors, timing is fine, knock sensor, air temp sensor, air filter, fuel filter, spark plugs and wires and both coils and it still does it.