I have a 2002 Corolla with 160,000 miles on it. 3 days ago I started the car in the morning and noticed my rpms was up around 2000. It is usually between 800-1200. Shortly after starting it, I put the car into reverse. the rpms went up to 2500 and the car shot backward at 30 mpg with no touching the gas pedal. Managed to stop it, put it into drive and noticed both the gas pedal and the brake pedal stuck. Have replaced coolant sensor, trottle position sensor, lubed everything in sight under the hood and pedal. Checked cables, etc. Everything seems to be fine except the problem continues to happen. It only happens from a cold start.
the pedal's are stuck or hard to push? those are totally different in my opinion. hard to push meaning it will move, just requires effort. stuck is well... stuck.
as for the gas pedal, test if the cable is binding by disconnecting it from the throttle body. then push the pedal. it should go to the floor with almost no effort. if it does not then the cable is your problem and i would replace it. also how did you lube your throttle cable?
as for the brake pedal, it sounds like their might be a vacuum leak in the system, this would cause a high idle and stiff pedal as you have described. but i would it would run very very poorly and cause a CEL to appear. since you didnt mention a random CEL appearing, i assume you dont have one?
have you checked behind the pedals inside the cabin by chance? to make sure there isnt anything obstructing them?
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Hard to push. With extra effort the gas pedal does move. The cable isn't binding. Everything was disconnected. When everything is disconnected the pedal moves freely. There is a spray product that is used to lube the cables. Also, thoroughly cleaned the throttle body, the butterfly, the cables, disconnected the cruise control, replaced O2 sensor, coolant sensor and trottle positioning sensor. Have not replaced idle motor or gas pedal. Did check behind and under the gas pedal, removed floor matt and the problem still occurs.
As for the brake-the only time it is hard to push is at the same time the engine is at 2000 rpm and the gas pedal is hard to push. No Cel, no errors, no leaks. Did replace a leaky seal under the hood.
The only time this is happening is when cold starting.
Quote:
Originally Posted by Milky
the pedal's are stuck or hard to push? those are totally different in my opinion. hard to push meaning it will move, just requires effort. stuck is well... stuck.
as for the gas pedal, test if the cable is binding by disconnecting it from the throttle body. then push the pedal. it should go to the floor with almost no effort. if it does not then the cable is your problem and i would replace it. also how did you lube your throttle cable?
as for the brake pedal, it sounds like their might be a vacuum leak in the system, this would cause a high idle and stiff pedal as you have described. but i would it would run very very poorly and cause a CEL to appear. since you didnt mention a random CEL appearing, i assume you dont have one?
have you checked behind the pedals inside the cabin by chance? to make sure there isnt anything obstructing them?
Yes the throttle plate moves freely as do the cables, the pedal (gas and brake) when not connected. When connected this is what happens.
Cold start with foot on brake. Do not press gas pedal. Note the rpms upon start. When the problem occurs the rpms are at 2000 and do not return to my normal range of 800-1200 until you put the car into reverse.
Still not touching the gas pedal, back the car up. Note that it is moving much faster than normal at this point (up to 35rpm without touching the gas pedal).
Bring the car to a stop. Rpms have not dropped to 800-1200. Put car in drive and slightly press the gas pedal. At this point the gas pedal will feel stiff and hard to push. By continuing to apply steady and harder pressure it will eventually free up.
That is the only time it does it. I do have to note that the day before the problem began a seal under the hood had to be changed. The entire area was cleaned before and after changing the seal.
With the cruise control, throttle plate, etc. disconnected the pedal moves freely.
Quote:
Originally Posted by Bitter
when everything is not connected, does the throttle plate move freely? work one part at a time till you find whats binding.
How cold is cold? Below freezing it may be your throttle plate freezing or somthing along those lines. As Bitter said, try moving the throttle plate by hand first, before stepping on the pedal or starting.
Also, if you have an automatic transmission, there is a kickdown cable that runs from the throttle body to the transmission, so check for binding there as well. You can temporarily disconnect this cable if need be, it just won't downshift at wide open throttle (which you can do with the shifter if/when needed).
And as stated, the hard brake pedal / poor brake performance is related to a lack of vacuum to the booster, caused by the throttle plate not closing or some other vacuum "leak".
Edit, just re-read the bit about cleaning under the hood. How was it cleaned? Pressure washed / steam cleaned? If so, you're probably looking at a freezing or corroding cable, likely the kickdown cable if you've checked / lubed the throttle cable.
Last edited by landphil; 02-17-2011 at 09:08 PM.
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Just regular cold as in first time starting car in the morning. I'm in Houston so temps in this area are around 60-70 in the mornings this time of year (although we did have 20's for a couple of weeks recently).
Did try the throttle plate by hand before stepping on pedal or starting. It is very free at that point.
Will check into the kickdown cablee for binding. Already checked the vaccum for leakage. Getting good vaccum to the booster.
Cleaned with a spray designed for that purpose. Spray was highly recommended by mechanic friends. Will check into the kickdown cable.
Brake performance appears to be related to gas pedal or rpm overriding braking system due to engine revving while gas pedal is hard to push. Brake performance returns to normal after the gas pedal releases.
Quote:
Originally Posted by landphil
How cold is cold? Below freezing it may be your throttle plate freezing or somthing along those lines. As Bitter said, try moving the throttle plate by hand first, before stepping on the pedal or starting.
Also, if you have an automatic transmission, there is a kickdown cable that runs from the throttle body to the transmission, so check for binding there as well. You can temporarily disconnect this cable if need be, it just won't downshift at wide open throttle (which you can do with the shifter if/when needed).
And as stated, the hard brake pedal / poor brake performance is related to a lack of vacuum to the booster, caused by the throttle plate not closing or some other vacuum "leak".
Edit, just re-read the bit about cleaning under the hood. How was it cleaned? Pressure washed / steam cleaned? If so, you're probably looking at a freezing or corroding cable, likely the kickdown cable if you've checked / lubed the throttle cable.
check the tps and make sure it is not binding and that its being installed correctly. it can be put on in such a manner to cause the throttle to stick. if this were happening, it could also hold the throttle open causing your car to take off when put into gear.
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Okay. Going to look into the kickdown cable, and reinstall the tps. BTW--what is the normal engine idle for a 2002 Corolla when you first start the car? In all the years I've owned this one I have always seen it between 800 and 1200. For the past 2-3 weeks it's been at 2000. The local dealership mechanics insist that this it normal.
Also, could the engine idle motor or the gas pedal itself be the culprit?
Will keep everyone posted. Thanks so much for all your advice.
Doubt pedal to be the issue, especially since it was moving pretty freely once you disconnected the cable.
The idle speed control valve on the throttle body could be the culprit. Could be anything from a stuck valve (lets in too much air, doesn't start stepping down when the temps start to climb), to a bad signal sent to the ECM which controls how many "steps" it needs to take.
Could also be a bad engine coolant temperature sensor, if the ECM "thinks" the temperature is too cold, it will hold the idle speed control valve open longer.
On my 2002 - even on cold mornings (15-20 degrees), revs are in the 1500-1800 RPM range, but quickly with some heat in the system. At the 50-60 degree cold starting temps - usually in the 1000-1500 RPM range. Once the temperature needle starts to move, idle usually drops in the 800-900 RPM range.
Thanks for the response.
The engine coolant temperature sensor has been changed (replaced it twice in 1 day because the first one was faulty). So, I'm reasonably certain that's not the cause. I'm going to revisit the throttle body itself. Will keep everyone posted.
Quote:
Originally Posted by fishexpo101
Doubt pedal to be the issue, especially since it was moving pretty freely once you disconnected the cable.
The idle speed control valve on the throttle body could be the culprit. Could be anything from a stuck valve (lets in too much air, doesn't start stepping down when the temps start to climb), to a bad signal sent to the ECM which controls how many "steps" it needs to take.
Could also be a bad engine coolant temperature sensor, if the ECM "thinks" the temperature is too cold, it will hold the idle speed control valve open longer.
On my 2002 - even on cold mornings (15-20 degrees), revs are in the 1500-1800 RPM range, but quickly with some heat in the system. At the 50-60 degree cold starting temps - usually in the 1000-1500 RPM range. Once the temperature needle starts to move, idle usually drops in the 800-900 RPM range.
^^ My goof, missed that you already got the coolant sensor in your previous post. Assuming that you replaced the throttle body gasket?
Everything you mentioned sounds like too much air is getting around the throttle body - ie. throttle plate is hung up or the idle-air valve is open too far. Like that old trick of drilling holes in the throttle plate to get extra air into the engine (Holley carbs). If you got the holes too large, idle speed will be excessively high, and because of it, available engine vacuum will be reduced.
I'm beginning to think like you said, the throttle plate may be hanging. I don't think it's a vacuum issue. That was one of the first things checked. Plenty of engine vacuum. I'm going to get a used throttle body and see if the problem goes away. Will keep everyone posted.
You guys are the best
Quote:
Originally Posted by fishexpo101
^^ My goof, missed that you already got the coolant sensor in your previous post. Assuming that you replaced the throttle body gasket?
Everything you mentioned sounds like too much air is getting around the throttle body - ie. throttle plate is hung up or the idle-air valve is open too far. Like that old trick of drilling holes in the throttle plate to get extra air into the engine (Holley carbs). If you got the holes too large, idle speed will be excessively high, and because of it, available engine vacuum will be reduced.
Replaced throttle body with a used one. Problem went away. Dismantled the original throttle body and found 2 issues. The butterfly was not functioning properly even after thorough cleaning. The only time it acted up was after a cold start, back the car up and then put into drive. Additionally, the section where the cables tie in was not working at all.
Car is now running at:
cold start rpm 800-1200
warm start rpm 900-1200
in operation rpm 1000-1500
No sticking, no hard to push.
Thank you to everyone who helped figure this one out.
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