Idle Hunting/Surging/Fluctuations after IACV cleaning attempt
This is a 2002 Toyota Corolla S with 186,000 miles.
I should I spent a lot more time Googling different threads and videos (for precautions) before I started it, but this is where I am at now (I watched just one YouTube video).
Also, I am admitting that I made a lot of mistakes, especially about choosing TODAY to do this project. I was in the middle (and not a participant) of some wacky neighborhood violence and drama. And all I wanted was to be left alone to get my car fixed up (Read #10). I may have forgotten something important.
So I started the car this morning, after reinstalling the cleaned components that I removed yesterday afternoon. Which is Throttle-Body and Idle Air Control Valve.
The results were alarming. It first started idling on it’s own at 2,000 RPM, and then it revved up to 4,500 RPM for a brief second before slowly dropping down to 1,500 and then constantly fluctuating between 1,500 to 3,500 as the car got closer to warming up. The OBDII Diagnostics report a P0300 Random Misfire code and the engine is running extremely lean.
So far the things I have done as well as diagnostics numbers
1. I cleaned out all of the inlets and outlets of the throttle body and IAC, except the IAC valve-motor. I didn’t want to risk stripping the copper-colored screws or damaging the motor (or solenoid or whatever). The only way I managed to separate the IAC from the TB was using vice grips and WD-40 on the four silver frail Philips screws. However, the video I watched said that there was a O-ring I had to clean and replace behind the valve motor.
2. However, I did manage to clean up as much of the carbon gunk as possible.
3. When I initially started the car after reassembly, I left the radiator cap off. To get started on burping it.
4. I DID NOT disconnect the battery before working on this project. I later learned, at least from both the Honda and Saturn forums, that apparently the car requires the battery to be disconnected for X-Amount-of-Time to “reset the ECU”, so the car can gradually learn to idle again (Cars had to learn how-to-idle?!?). However, I read another post somewhere in a different Toyota forum (either Tundra or Tacoma), that it is not advisable to unplug the battery, and that “it can make the problem worse”. So I still have not done it, unless you guys assure to me that it will help.
5. The Short and Long-Term Fuel Trims read 14.1% Positive, or basically, really really lean. As the car is rumbling like a pipe organ, the LTFT barely fluctuated beyond 0.1% so I was really certain there is a vacuum line leak
6. After turning the car off, I checked all vacuum lines from the airbox to the throttle body. I didn’t replace the hoses yet, whenever I felt a loose hose I tightened it with a new clamp.
7. I found a hairline crack on the airbox. I didn’t take a picture of it, but I rubbed a thin layer of Permatex Ultra Black on it, and then covered it with a thin-strip of duct tape.
8. I have a MAP sensor reading of “no-data”. Except I don’t recall ever encountering a MAP sensor during this project. I looked online at the forums, and there was a lot of confusion on which model of the 1998-2002 Corolla actually possessed one. I do not see connectors or ports to where a MAP sensor could plug into on top of the throttle body. I did however, saw additional vacuum hoses in the intake plenum behind the radiator hose, which I didn’t mess with (aside from scrubbing the reachable ends of the intake plenum). I googled a replacement MAP sensor for a 2002 Corolla 1ZZ-FE, and I kept getting different variations of the sensor. One looked like a coil-pack with tubes, another one had a bottom that looked like a light bulb.
9. I also have a P0442 “EVAP leak” code. I largely ignored it because I had that code for years and all I do is avoid filling up my gas tank completely to prevent it from coming back after I clear it.
10. A brawl broke out right next to me and my car. Because of that, I may have forgotten a CRITICAL part of the process. Right in the middle of me working on this project in my apartment complex, around noon when the sun is getting hot, a fight broke out between one of my neighbors and some crazy looking tweaker guy.
At first, I thought the tweaker was trying to steal my tools, but he was headed to his creepy-tweaky-buddy in a van that was parked (poorly) right next to my car. On my right, was my neighbors, pissed as all hell, mouthing off threats to the tweakers on my left (I believe I saw a handgun in my neighbor’s car, we conversed 20 minutes earlier before the tweakers showed up to start shit, and this neighbor seems to be pretty “hardcore”) As they continued fighting, with me in the middle (and I am not even trying to stop it), I calmly (nervous actually) got my machete (still sheathed) out of my car, and left it in front of my feet and kept on working on my car. Eventually, the tweakers started cleaning their windows on their rape-van and left.
But I am certain the tweakers didn’t manage to steal anything. Unless, that’s where my invisible, imaginary MAP sensor went (and God knows where am I supposed to attach it on the throttle body). What do you think a tweaker could use with a stolen Toyota MAP sensor anyways? Is it a vital component to “get their tweak on”?
It was the most tense half an hour I ever been through, while pretending like I was deaf. My hairs were pretty highly raised right then.
I didn’t even have a gun, but I was SURROUNDED by various sharp OR heavy objects (commonly called “tools”). If that tweaker midget dude lunged for my machete, I still have four socket wrenches within arm’s reach to bonk him on the head with. Oh, and the car was still hot. And I was standing right in front of the radiator cap. So basically, Plan A: Hack, Slash, Stab, and Plan B: Bonk-Scald-and-Burn.
Five minutes after this incident, there was another altercation at the other end of the apartment complex, featuring (I am certain), a completely unrelated party. When I saw THAT GUY speeding down the parking lot towards me and hitting those sharp speed bumps at full throttle, I was looking at his shoulders for sudden movements and getting ready to duck, thinking I was gonna get my head shot in a drive-by.
So yeah. The time I should have spent paying attention to my work, left me really shakey instead. I was expecting ambulances and police cruisers to be swarming the immediate block for the next two hours.
I literally looked like a cautious prairie dog once all that stuff happened.
11. I tried substituting the hard-to-find gasket with Permatex Ultra Black RTV. I tried looking for a replacement IACV gasket locally, but no Autozone, O’Reilly’s, or Pep Boys have any in stock. The gasket has a unique shape, and 75% of the Google search results I found for “2002 Corolla IACV Gasket” turned up a completely different product, where the coolant and idle air passages are rectangular and square.
The gasket that I need, looks like a face, two eyes (one smaller than the other), and a “mouth”. I finally found one for $9 online, but it’ll come in five days.
Since I was being impatient, I thought maybe Permatex RTV would do the trick. I carefully spread around the sealant with a small screwdriver between all of the “canals” of each chamber, and then wiping off the overflow to avoid getting any of this stuff sucked into the engine or coolant passages. As it dried, I added a “second layer” on top to create the “gasket effect”. I then waited half a day (until I woke up), before reassembling the TB + IACV.
I’m thinking, maybe the sealant was too fragile to contain all of the pressure from both coolant and incoming air from the idler holes. And that a piece of sealant may have broken off and jammed the valve of the IACV, causing it to remain open, and constantly introducing excess air into the manifold.
12. The flow of the Mass Air Flow Sensor more than doubled. At “idle”, the car is now between 0.9 to 1.1 Pounds/Minute. Formerly, before this project, the car averaged between 0.2 to 0.4 Pounds/Minute at idle. Initially, I thought there was a leak before the MAF/IAT, but then I realized this excessive airflow is caused by the vacuum leak farther down the intake.
This time, I want to do it right, without having to backtrack and making sure the car actually idles normally. I am planning to…
1. Strip down the entire intake from air-box to manifold plenum, again.
2. Finally try to get those IAC valve motor screws out so I can clean it too
3. Un-gunk my half-assed “RTV gasket job”
4. Start checking and replacing the intake manifold vacuum hoses, starting with wherever is the EVAP hose led to underneath the radiator hose. Since the vacuum leak is mainly referring to MANIFOLD VACUUM, all I have to do is check and replace the hoses ONLY from the intake manifold to the airbox right? Because that P0442 EVAP leak code could be anywhere, from the engine bay to the gas tank.
5. Bring friends. Friends with guns, or some sort of intimidating improvised weaponry, and just stand next to me and my car looking “really mean” so I can finish my fixing. No way am I gonna be distracted by my ghetto neighborhood. If you would like to be my car-fixing friend/bodyguard, LMK. You can wield any of the “weapons” you find in my possession for the time being.
This is a 2002 Toyota Corolla S with 186,000 miles.
I should I spent a lot more time Googling different threads and videos (for precautions) before I started it, but this is where I am at now (I watched just one YouTube video).
Also, I am admitting that I made a lot of mistakes, especially about choosing TODAY to do this project. I was in the middle (and not a participant) of some wacky neighborhood violence and drama. And all I wanted was to be left alone to get my car fixed up (Read #10). I may have forgotten something important.
So I started the car this morning, after reinstalling the cleaned components that I removed yesterday afternoon. Which is Throttle-Body and Idle Air Control Valve.
The results were alarming. It first started idling on it’s own at 2,000 RPM, and then it revved up to 4,500 RPM for a brief second before slowly dropping down to 1,500 and then constantly fluctuating between 1,500 to 3,500 as the car got closer to warming up. The OBDII Diagnostics report a P0300 Random Misfire code and the engine is running extremely lean.
So far the things I have done as well as diagnostics numbers
1. I cleaned out all of the inlets and outlets of the throttle body and IAC, except the IAC valve-motor. I didn’t want to risk stripping the copper-colored screws or damaging the motor (or solenoid or whatever). The only way I managed to separate the IAC from the TB was using vice grips and WD-40 on the four silver frail Philips screws. However, the video I watched said that there was a O-ring I had to clean and replace behind the valve motor.
2. However, I did manage to clean up as much of the carbon gunk as possible.
3. When I initially started the car after reassembly, I left the radiator cap off. To get started on burping it.
4. I DID NOT disconnect the battery before working on this project. I later learned, at least from both the Honda and Saturn forums, that apparently the car requires the battery to be disconnected for X-Amount-of-Time to “reset the ECU”, so the car can gradually learn to idle again (Cars had to learn how-to-idle?!?). However, I read another post somewhere in a different Toyota forum (either Tundra or Tacoma), that it is not advisable to unplug the battery, and that “it can make the problem worse”. So I still have not done it, unless you guys assure to me that it will help.
5. The Short and Long-Term Fuel Trims read 14.1% Positive, or basically, really really lean. As the car is rumbling like a pipe organ, the LTFT barely fluctuated beyond 0.1% so I was really certain there is a vacuum line leak
6. After turning the car off, I checked all vacuum lines from the airbox to the throttle body. I didn’t replace the hoses yet, whenever I felt a loose hose I tightened it with a new clamp.
7. I found a hairline crack on the airbox. I didn’t take a picture of it, but I rubbed a thin layer of Permatex Ultra Black on it, and then covered it with a thin-strip of duct tape.
8. I have a MAP sensor reading of “no-data”. Except I don’t recall ever encountering a MAP sensor during this project. I looked online at the forums, and there was a lot of confusion on which model of the 1998-2002 Corolla actually possessed one. I do not see connectors or ports to where a MAP sensor could plug into on top of the throttle body. I did however, saw additional vacuum hoses in the intake plenum behind the radiator hose, which I didn’t mess with (aside from scrubbing the reachable ends of the intake plenum). I googled a replacement MAP sensor for a 2002 Corolla 1ZZ-FE, and I kept getting different variations of the sensor. One looked like a coil-pack with tubes, another one had a bottom that looked like a light bulb.
9. I also have a P0442 “EVAP leak” code. I largely ignored it because I had that code for years and all I do is avoid filling up my gas tank completely to prevent it from coming back after I clear it.
10. A brawl broke out right next to me and my car. Because of that, I may have forgotten a CRITICAL part of the process. Right in the middle of me working on this project in my apartment complex, around noon when the sun is getting hot, a fight broke out between one of my neighbors and some crazy looking tweaker guy.
At first, I thought the tweaker was trying to steal my tools, but he was headed to his creepy-tweaky-buddy in a van that was parked (poorly) right next to my car. On my right, was my neighbors, pissed as all hell, mouthing off threats to the tweakers on my left (I believe I saw a handgun in my neighbor’s car, we conversed 20 minutes earlier before the tweakers showed up to start shit, and this neighbor seems to be pretty “hardcore”) As they continued fighting, with me in the middle (and I am not even trying to stop it), I calmly (nervous actually) got my machete (still sheathed) out of my car, and left it in front of my feet and kept on working on my car. Eventually, the tweakers started cleaning their windows on their rape-van and left.
But I am certain the tweakers didn’t manage to steal anything. Unless, that’s where my invisible, imaginary MAP sensor went (and God knows where am I supposed to attach it on the throttle body). What do you think a tweaker could use with a stolen Toyota MAP sensor anyways? Is it a vital component to “get their tweak on”?
It was the most tense half an hour I ever been through, while pretending like I was deaf. My hairs were pretty highly raised right then.
I didn’t even have a gun, but I was SURROUNDED by various sharp OR heavy objects (commonly called “tools”). If that tweaker midget dude lunged for my machete, I still have four socket wrenches within arm’s reach to bonk him on the head with. Oh, and the car was still hot. And I was standing right in front of the radiator cap. So basically, Plan A: Hack, Slash, Stab, and Plan B: Bonk-Scald-and-Burn.
Five minutes after this incident, there was another altercation at the other end of the apartment complex, featuring (I am certain), a completely unrelated party. When I saw THAT GUY speeding down the parking lot towards me and hitting those sharp speed bumps at full throttle, I was looking at his shoulders for sudden movements and getting ready to duck, thinking I was gonna get my head shot in a drive-by.
So yeah. The time I should have spent paying attention to my work, left me really shakey instead. I was expecting ambulances and police cruisers to be swarming the immediate block for the next two hours.
I literally looked like a cautious prairie dog once all that stuff happened.
11. I tried substituting the hard-to-find gasket with Permatex Ultra Black RTV. I tried looking for a replacement IACV gasket locally, but no Autozone, O’Reilly’s, or Pep Boys have any in stock. The gasket has a unique shape, and 75% of the Google search results I found for “2002 Corolla IACV Gasket” turned up a completely different product, where the coolant and idle air passages are rectangular and square.
The gasket that I need, looks like a face, two eyes (one smaller than the other), and a “mouth”. I finally found one for $9 online, but it’ll come in five days.
Since I was being impatient, I thought maybe Permatex RTV would do the trick. I carefully spread around the sealant with a small screwdriver between all of the “canals” of each chamber, and then wiping off the overflow to avoid getting any of this stuff sucked into the engine or coolant passages. As it dried, I added a “second layer” on top to create the “gasket effect”. I then waited half a day (until I woke up), before reassembling the TB + IACV.
I’m thinking, maybe the sealant was too fragile to contain all of the pressure from both coolant and incoming air from the idler holes. And that a piece of sealant may have broken off and jammed the valve of the IACV, causing it to remain open, and constantly introducing excess air into the manifold.
12. The flow of the Mass Air Flow Sensor more than doubled. At “idle”, the car is now between 0.9 to 1.1 Pounds/Minute. Formerly, before this project, the car averaged between 0.2 to 0.4 Pounds/Minute at idle. Initially, I thought there was a leak before the MAF/IAT, but then I realized this excessive airflow is caused by the vacuum leak farther down the intake.
This time, I want to do it right, without having to backtrack and making sure the car actually idles normally. I am planning to…
1. Strip down the entire intake from air-box to manifold plenum, again.
2. Finally try to get those IAC valve motor screws out so I can clean it too
3. Un-gunk my half-assed “RTV gasket job”
4. Start checking and replacing the intake manifold vacuum hoses, starting with wherever is the EVAP hose led to underneath the radiator hose. Since the vacuum leak is mainly referring to MANIFOLD VACUUM, all I have to do is check and replace the hoses ONLY from the intake manifold to the airbox right? Because that P0442 EVAP leak code could be anywhere, from the engine bay to the gas tank.
5. Bring friends. Friends with guns, or some sort of intimidating improvised weaponry, and just stand next to me and my car looking “really mean” so I can finish my fixing. No way am I gonna be distracted by my ghetto neighborhood. If you would like to be my car-fixing friend/bodyguard, LMK. You can wield any of the “weapons” you find in my possession for the time being.
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