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02 2.4 IL4 2AZ-FE - Where are the TB and MAF/MAP and best way to clean them?

7K views 13 replies 5 participants last post by  Texavant 
#1 ·
I Kreened the engine last month...misfire is worse.
Next I need to clean the TB and MAF/MAP.
Where are they on engine and what is the best way to clean them?
Also, what is the best technique to detect vacuum leak?

Had codes read and it read misfire 1,2,3 and VVTi problems.
 
#2 ·
Cleaning the MAF and TB are not really going to help with misfires unless you also had a MAF related P0171.

The MAF sensor is located on the top of the air box. It's held on by 2 Phillips screws and one connectors. It has kind of a square shaped body.

The TB is located behind further down the intake tract behind the engine. The air intake tube has to come off.

Is your car an XLE? IIRC 02 XLE had a DBW (Drive by Wire) throttle and CE/LE had a cable throttle.

Use this link and post #3 to clean your throttle body. If its a cable throttle ignore the part about the clamp (different style). If its DBW then just pretty much follow the link.

http://www.toyotanation.com/forum/1...007-2011/415038-what-controls-ac-idle-up.html

Has the Kreen corrected the VVT-I codes?
 
#3 · (Edited)
#8 · (Edited)
Based on hardtopte72 's post, I put together a quick video showing how to clean the throttle body on the 2AZ-FE 4 cylinder engine.

There wasn't much pictures or videos out there for the 2AZ-FE, so I hope this can help someone:

http://www.youtube.com/watch?v=pnrAMZlkSSA
Thats how I do it! Somebody on here was telling me the power was not required, you can push the motor with the key out, had done it many times. Forget who said that. I was too scared of stripping the motor and making the plates loose, so I do it like you. BTW there is a small hole in there, similar to an IAC hole. At 3:50, its right below your toothbrush, below the plate closed line, down almost to the screen level. I was able to flood it with TB cleaner till it gushed back out. was vary gunked up. Can't call it an IAC hole, don't know that that hole is.
 
#10 ·
Thanks, I'm glad I can help someone.

Thats how I do it! Somebody on here was telling me the power was not required, you can push the motor with the key out, had done it many times.
At first I thought I could do it with the key out- but that meant holding the throttle valve open with my fingers as it seemed spring loaded--that's kinda tricky to do with the toothbrush in the other hand. So I just set it open by flooring the throttle, makes the job easier.

I definitely notice an improvement in performance after cleaning the throttle body, even though mine wasn't that dirty. I don't have to press as hard on the gas to get going, and the car seems to roll more than engine brake when my foot is let off. Throttle response makes the car feel zippier now.
 
#6 ·
for the readers that have newer than '02 its basically the same but the components are a little different.

In the case of my '07, I needed to remove the intake resonator to get at the clamp neat the throttle body and it has a vacuum line connected to it. At the time, due to lack of knowlege, I twisted the resonator to remove it because it was stuck, that sheared the tit that has a vacuum line connected to it. I ended up haveing to replace the resonator since I knew that the JB weld would eventually fail because of the engine heat.

Mine looked considerably dirtier than the video, especially the honeycomb looking part in the throat.
 
#7 ·
I never remove the resonator for exactly that reason. They almost always break off. It's a little harder but the clamp can be removed with the resonator in.

I will post pics when I redo my 09 so Gen 6 owners can get a more specific idea.
 
#9 · (Edited)
Would be nice to see the actual codes. I would say thats 2 different problems. Not sure what you mean by Kreened, but in the oil, Kreen is very effective removing carbon and varnish buildup in the VVt-i system. A P1349 for example. The vapors also clean the PCV inlet and valve. In some cases the OCV screen needs to be removed and cleaned manually to get proper oil flow. Oil thats too thick can also cause the vvt-i controller not to function properly. No thicker than a 5w30, synthetic is the best choice for cold oil flow and to prevent deposits. Make sure the PCV valve and hose are connected and function properly

The misfire codes (if they are P0301, P0302, and P0303). In addition to the recommendations above, misfires can also be caused by a bad coil or a bad/wrong plug type. Swapping the one coil that is not reporting an error with one that is can help diagnose. Use Iridium plugs only. NGK or denso.

A faulty injector can cause misfires. Try unplugging them and plugging back in. The rubber o-ring around the injector hardens and shrinks over time, creating a vacuum leak that could cause a misfire. Replacement is not easy unless you know how, save that for a last resort. Fuel system/injector cleaner with a PEA additive like techron concentrate may help, but unlikely the problem. Try a bottle down the brake booster with engine set to 2500 rpm, and a bottle in the tank. But again thats unlikely to resolve the problem.

Old coolant can cause misfires believe it or not. Innacurate reading of coolant temps can set the fuel/air mix too lean, too rich. Advance and retard the VVT-i controller into the wrong position. Use Toyota Red LLC concentrate only. Mix 50/50 with distilled. Drain and fill is enough. Could be the coolant temp sensor but I haven't seen that on this engine.
 
#14 ·
There was also a code for water temp sensor...

Old coolant can cause misfires believe it or not. Innacurate reading of coolant temps can set the fuel/air mix too lean, too rich. Advance and retard the VVT-i controller into the wrong position. Use Toyota Red LLC concentrate only. Mix 50/50 with distilled. Drain and fill is enough. Could be the coolant temp sensor but I haven't seen that on this engine.
Actually there was a code for water temp sensor but I ignored it because we had replaced the radiator last month.
 
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