Throttle body cleaning

[DanTavensis]

The avensis is having trouble with the throttle body getting stuck, this is causing a problem with acceleration and will not go over 2k revs, it is perfectly fine when the engine is hot. With the colder weather coming i need to clean it.

So first question is, i have the 1az-fe 2.0 litre 2004 petrol engine. Is it OK move move the throttle body flap to get in and clean with a rag. My mechanic has said this is a definite no,no. But i've seen the car care nut on you do otherwise. So i 'm just wondering if any of you experts can tell me whats what?

[TonyHSD]

Do not remove the throttle body flap, if you do so you may have trouble with idle afterwards, also when cleaning use only specific spray for throttle body and nothing else. You can remove the body from intake , no need to disconnect the coolant hoses just twist and work like that, you can spray directly into the flap from both sides and into rug and clean using something softer like plastic stick to push the rug and clean it properly. There might be some metal glue like around the axle ends of the flap, these are not to be removed while cleaning, keep them intact. And once it’s clean and dry put back and make sure gasket is correct way installed. 👍If you don’t remove the body from intake then do not spray directly into it but only on the rug and clean working around with the cloth. 
Good luck 

[DanTavensis]

So is it ok to push the flap open with fingers?

[TonyHSD]

22 minutes ago, DanTavensis said:

So is it ok to push the flap open with fingers?

Yes, but make sure you push the right way, only opens one way, if it doesn’t don’t force it, I had cleaned many different throttle bodies including the electronic ones like on Prius , not sure on your particular car what type it is but you can try slowly and if it’s no resistance then open it and clean. Usually when throttle body causes issues because it’s dirty most likely happens in hot temperatures., like summer time or after long drive. You can clean the whole body and the flap without touching them with rug just with the spray power but make sure body is out of the intake and no dirt or liquid goes into the intake manifold as can be sucked into the engine afterwards. 👍

[Rosgoe]

I have read that with certain cars where the throttle is controlled by fly by wire as apposed to a throttle cable by moving the throttle butterfly with your fingers can sometimes throw up a fault code.

[DanTavensis]

Yes i'm pretty sure my car uses this fly by wire and was worried about this.

[TonyHSD]

43 minutes ago, DanTavensis said:

Yes i'm pretty sure my car uses this fly by wire and was worried about this.

No problems at all if you can move it freely. The reason why is not recommended it’s  because there are gears inside the throttle body mechanism and some can be worm gears that can only turn from the electric motor but not other way around from the flap itself and if your body is one of those types and you force it you can damage it, that’s why just try it slowly and in general be gentle when open and close the flap. Prius has no issues I,can confirm that. Here it’s mine when I was cleaning the egr and everything including the throttle body. 

[2009joe]

quick question i have watched a few vidoes online about cleaning the t27 2.0 d4d 1adftv engine an dwell im wondering when should it be cleaned out as im not sure the problem with me i dont travel far so i do short runs maybe sometimes at weekends go for a nice run. im wondering when should i clean mine out and how ofton .the car i got it came with 38k and now it has 44k and i have it 1 year

 

[DanTavensis]

I'm wanting to give the car a italian tune up. Will it be safe to keep the revs at 4k for 30 minutes without causing damage. I suppose my question is will this motor take it?

[Stivino]

6 minutes ago, DanTavensis said:

I'm wanting to give the car a italian tune up. Will it be safe to keep the revs at 4k for 30 minutes without causing damage. I suppose my question is will this motor take it?

What do you hope will be the outcome of the “Italian tune up”?

[Red_Corolla]

38 minutes ago, DanTavensis said:

I'm wanting to give the car a italian tune up. Will it be safe to keep the revs at 4k for 30 minutes without causing damage. I suppose my question is will this motor take it?

All production engines have a statistic called 'maximum continuous operating speed'. This usually coincides with the beginning of the red zone on the rev counter. 4k is going to be fine for most car engines, but it's always a good idea to keep an eye on the temperature, especially when driving hard.

[AisinW]

It is never a good idea keeping rev above 3500 rpm in most engines unless you have the speed than cool the engine properly.  

Cleaning throttle body in Toyota is easy  as long as you push it gently and release it gently. I did it on my prius 06, auris 2015, Sienna V6 3.5L, without any issue. Make sure clean the  meeting surface to the flap and the edge of the plate/flap. I use isopropanol or alcohol. 

 

[DanTavensis]

I will clean it soon as in the morning when the car is cold i keep losing all power as in will not rev, i have to keep pressing the accelirator peddle, the itialian tune up was to clean the injectors, maybe i keep it at 3500k on highway

[AisinW]

19 hours ago, DanTavensis said:

I will clean it soon as in the morning when the car is cold i keep losing all power as in will not rev, i have to keep pressing the accelirator peddle, the itialian tune up was to clean the injectors, maybe i keep it at 3500k on highway

Italian tune up will do nothing in your case, besides wasting fuel. It is not injector issue because it runs fine when the engine is warm.  It means only during open loop, not close loop.  Do you have idle problem too? Especially when it is cold, just start up. 

You must clean the throttle body first, before anything else. Use pure IPA or carburator cleaner.  

Have a good OBD2 scanner to pinpoint what is the cause.  Check your EGR valve too, in case it is stucked close or open. 

[TonyHSD]

“Italian tune up” seems to me like a fast and secure way to damage your car. It will clean nothing for sure. The idea of keeping the car at higher revs for some time and especially when you have additives added to the fuel is to rise the temperature in combustion chambers and burn any accumulation of soot or carbon buildup and clean also the catalytic converter and lambda sensors, all that should happen on the motorway not at idle with parked car, as mentioned the engine will need an air stream for cooling outside. As suggested earlier, clean throttle body properly, then you can use this one https://www.ebay.co.uk/itm/WYNNS-CATALYTIC-CONVERTER-LAMBDA-CLEANER-OXYGEN-SENSOR-325ML-/393432200811?mkcid=16&mkevt=1&_trksid=p2349624.m2548.l6249&mkrid=710-127635-2958-0 with max of 30 litres of petrol and take the car for a motorway run for at least 30 min no need to be 3500rpm or super higher speed , 65-70mph but try to drive for as long as you can, this is what rises temperature and cleans the things. I have done successfully with that stuff on my Auris and previously on other Japanese petrol engines rough idles and poor acceleration issues. 👍 Can not guaranteed it’s gonna work for you too but if you want to try as idea only . 
Good luck 👌

[AisinW]

In the past I added many kinds of additives: Seafoam, gumout, BG44k, Techron, BASF.  They never fix my crappy idle or rough starts.  The solutions I found in 3 different cars: 

1.  MAF sensor is contaminated with a dirt/cotton fiber and after cleaning it with MAF cleaner, it works great in Corolla 2001

2. Disconnected one of the purge valve small rubber hose.  After I connected, the Lean and rough idle completely gone. Altima 2002

3. Crankshaft position sensor dying and rattling at light acceleration.  Altima 2002

4. Opened EGR valve in my Auris 2015. I forgot to screw the EGR rotor completely in before putting the magnetic/plastic cap back.  It is spring loaded.  It shaked violently 

 5. Dirty Throttle body, it died when driving in parking lot and low idle, sticky gas pedal too in Sentra 1999. 

I suggest you visit very reputable experience mechanics to diagnostic it.  It is pretty strange because you cannot rev-up when it is cold.  Instead of bad idle when it is cold or warm.  Most likely not vacuum problem but something to do with electronics that prevent the throttle and injector rev above 2000 rpm.  If you DIY, Throttle body, MAF, and EGR are the first steps. 

 

[DanTavensis]

Thanks I’ve given the throttle body a short clean I’m going to get a garage to take off and clean. Thanks for the advice about Italian tune up. I was only gonna do it on motorway. 
the obd has come back with fuel pressure rail sensor being bad. I’ve noticed I did not get rough idling or loss of power after a short clean of the throttle body so I’m pretty sure it’s this. 

[DanTavensis]

Throttle body was taken out and cleaned with a pro mechanic doing the job. Problem still exists and is progressively getting worse, once the car is warmed up it drives fine , when cold the power cuts in and out.

Fault code points to the fuel pressure sensor. Car mechanic said take it to toyota dealer as he cannot get to the sensor or high pressure pump without taking the engine block off first. He said i'm looking at a 4 figure sum to sort out.

Engine code p0191, well i'm off to toyota dealer right now and will explain the situation abit more later on.

[DanTavensis]

Well looking like a thousand pound fix as they will not just change the sensor over for a new one, the whole pressure rail needs replacing thats after a diagnostic.

[DanTavensis]

It’s a bad fuel pump as it is it’s going to cost 1.4k to fix. Either that or it’s worth scrap, bit gutting though 

[DanTavensis]

Well its got to the high pressure pump is now wrong a hidden fault they called it and now its upto 2.5k i owe.

[TonyHSD]

That’s a bad news. Your car actually has the engine that is not compatible with latest standard of regular petrol E10 95 octane. Have you driven the car with this petrol for some time or you always been using E5 ? Just out of curiosity. If you have to pay that kind of money for repair on a 2004 model avensis , I am not sure is worth it but you know it’s your and only choice to make , for you might be reasonable., we all have different priorities and budgets. Wish you good luck . 

[DanTavensis]

Hi, only ever use supreme fuel from esso with no ethanol added.

Its not really worth it but they done the first job guaranteeing it would fix it then this extra problem after. So as i agreed to pay the first lot and did not fix it and owe them for it i thought go ahead and fix the dam car.

One thing i will be keeping this car for a while.