Cleaning Throttle Body

[BigMo82]

Ok here is an update. I took the old throttle body out which was not too bad to do other then the hose behind it which I believe is the inlet for the coolant. I left it hanging there and only realised after I had lost about 0.5 litres of coolant. Put the replacement in and reconnected the Battery. Turned the car on and it immediately threw up a fault code P2103 which I believe is throttle body failure. I tried to accelerate and it wouldn't go over 1400rpm.

So the replacement part from the breakers was knackered. Put the old throttle body back in but all in it was about an hours work. Popped the old 1 back in and the idle returned to full power and I could accelerate as normal again. Going to give the breaker a call as he guaranteed it was working fine.

Mo

[Konrad C]

Great result Mo. I think your car is fine. The idle probably was still settling down with the miles. I thought there could be a leak cause the idle to fluctuate.

Just return the other throttle body back to the scrappy.

See how the car runs for the next few days.

Konrad

[BigMo82]

Cheers Konrad, the idle still fluctuates a little but it does so between 620 - 780 ish and normally settles around 700 which is a great improvement. I think the Ecu is constantly adjusting it according to what is being used in the car. Just wish there was a way I could set it to 750.

Also I will pop into Kwik Fit tomorrow to get the Battery checked as its about 2 years old but has a 3 year warranty. Don't think a dodgy Battery could cause a fluctuating idle but it will help me tick the Battery and alternator off the checklist.

Does anyone know if Toyota can set the ecu to idle at a set speed? Like I said I'm pretty happy with how it is driving now but I am curious. I would happily swap these electronic throttle bodies for the old cable ones!

Mo

[Vlado P.]

i was just looking at the service specifications. the specification is 700 +- 50rpm when idle, so 750 is normal, although borderline.

as i said earlier, economy wise, 650 is ideal. lower than that and vibrations start to develop in the cabin.

i'm guessing these numbers assume all electrics off (radio, A/C, lights etc.)

[BigMo82]

Thanks for the reply. It only occasionally drops to 600/650. But as its only been reset 25 miles ago I'm guessing it takes a little longer before the ecu sets itself.

Mo

[Vlado P.]

You should try driving it on open roads in higher revs, so that the ecu can better map the open throttle position

[Lankaster]

Hi Gents,

As you can see I am new in this forum, as I have just sold my old VW Passat, abandoned their forum, bought Toyota and joined this forum. I was actually googling about Toyota idle speed and found this discussion which is still going on.

At the moment and am still familiarizing myself with Toyota and petrol engine altogether (I had 1.9 TDI diesel 130PS automatic). I had Toyota for a week now, despite windscreen jet pump not working (which replaced yesterday), Iridium spark plugs on the way from eBay (NGK) I have noticed that my engine idle speed is about 600 rpm. When I start it cold it sits at about 1600 rpm and once the engine is fully heated it drops to 600, sometimes even below which makes a bottle of water all shaking on the dashboard. I have take air intake off from the TB and cleaned the butterfly inside the TB. Didn't really bother taking the whole TB off hence just sprayed the inside of TB with WD40 and cleaned it with a cloth. However it was not very dirty whatsoever. Just some !Removed! on the edges of the butterfly. Do not think this could have made all this problem with the idle speed. After the test drive the outcome - the idle stops at about for 900 rpm once running on neutral gear and sits at this speed for about 5-10 s. once completely stopped and then drops to 620-650 rpm.

Should I be looking for a problem? It was not that shaky though, because that difference between 570 and 620 makes a huge effect on vibration. I am thinking maybe resetting the ecu, but how to do it with an ignition key as someone mentioned above?

Thanks in advance.

Darius

[Vlado P.]

Hello!

First of all you should not have used wd40! There are dedicated throttle body cleaners for the job! Anyway that little smudge is what makes all the trouble. Anyway it seems that your car works fine now. It is normal to idle a little higher for a while and than drop to the required ~650 rpm.

Can you send me a link as to which spark type did you order?

[Lankaster]

Please don't say these are not good for my engine. I was looking really for replacement plugs as the ones in the engine are quite worn I believe:

http://www.ebay.co.uk/itm/290762393908?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

How WD40 can harm my engine? I have pretty much absorbed all WD40 with the cloth hence none went inside, just a smell perhaps.

Besides in terms of engine idle speed I will see if going forward it will drop down to below 600 as it was not always below 600 but on some occasions only. So I think resetting ecu would help.

[Vlado P.]

You should consult the manual for the spark type since yours is a 1.8 engine. Mine are 3 electrode iridiums and cost arm and a leg.

Regarding the wd-40, it is a penetrating fluid that could damage the injectors, dissolve gaskets etc. And not only that, but once you start the engine that crap will flow through the catalytic converter, which can very easily be damaged.

If you managed to absorb most of it, great. I flushed half of can of tb cleaner through the injectors, when I was cleaning the tb.

[Lankaster]

I have read somewhere if you originally had spark plugs with 1 electrode it does not necessarily mean you will get better performance with 3 electrodes so just went for simple but Iridium. The only real difference between Iridium and copper altogether is the lifetime. Also Iridium are already pre-gaped. If you have noticed a significant difference after changing yours to 3 electrode iridium is only because your old ones were in need to be changed. I think you would have got the same performance at first changing to NEW 1 electrode copper ones. Nevertheless these are just comments from garages.

[Vlado P.]

these are the factory spark plugs. i haven't replaced them yet, since the car has only 65k km. according to the manual, they should be replaced on 100k, although i don't think they would last that long.

i have heard of people having worse performance when replacing their 1 electrode sparks, with 3 or 4 electrode ones. i guess you should stick to the factory recommendation when it comes to sparks.

[Lankaster]

Toyota I have purchased another week was serviced at Toyota Garage last couple of years and has 96k on the clock. The other thing with revs is that when I press the clutch when changing gears my revs goes up by ~200-400 and then goes down, every time and press the clutch. And yes, I completely release the throttle so it is not because I still touch it.

[BigMo82]

Still not quite sitting right and is fluctuating. I understand it should go between 650-750 but mine is 620-780. Any ideas how many miles the car has to be driven before the ecu starts setting up the throttle position.

Called Toyota main dealer today and they said that they have no machine or software to adjust the idle which I found a little odd.

Mo

[Vlado P.]

Probably ~200-300 km

[BigMo82]

Driven the car about 200 miles and still no difference. The revs are still hunting between 600 to 800 rpm. Cleaned the Maf sensor and that didn't change anything. What I find is if I drive it in traffic it seems to drop to 600 everytime I dip the clutch. If its driven at normal speeds the idle seems to remain better. Could it be a vacume leak? Or a problem with the ecu software?

Mo

[Vlado P.]

ecu software problems should clear when the Battery is disconnected.

i still think the TB was not cleaned properly. does the car work OK when cold?

[BigMo82]

Thanks for the reply Vlado. It works fine when cold but if the weather is warm or the car is driven for more then 20 - 25 mins that's when the problem usually occurs.

Mo

[BigMo82]

I have checked the throttle body and its got a nice clean gap all the way around the butterfly.

Mo

[Vlado P.]

i'm no mechanic, but your symptoms sound to me like the TB. the IAC seems to work fine, but once the IAC is closed, your problems start.

try to clean the TB again. use a toothbrush and clean deeper behind the butterfly. afterwards, rinse the tb abundantly with the TB cleaner. rinse the tb while somebody else revs the car, so that the gunk can flush through the injectors.

also, using the toothbrush clean the inner side of the butterfly. i used liqui moly's throttle cleaner, but frankly either the cleaner was crap, or my TB was very dirty. i have heard that wurth's cleaner is supposed to be good in dissolving the gunk.

p.s. have you checked the condition of the TB gasket?

[BigMo82]

Thanks for the reply, I haven't actually checked the throttle body housing but it was something I had previously thought of. Also I can't locate the idle air control valve. This may sound silly but does every car have one? I have taken the throttle body off and that has no removable parts and it looks completely electronic.

Mo

[frankie406]

have you checked the air intake manifold gasket? cleaned the connector plug for the throttle body and pushed in tight..all hoses connected right?also how is your braking system? is everything ok with your brakes? i put new pads all round on mine and the idle was up and down a good bit until they bedded in.

[Vlado P.]

Mo, did you remove the TB before cleaning? i think i had mentioned somewhere on the forum, but sometimes when removing the TB, the TB position sensor gets somehow misaligned, and requires recalibration.

i think this is for older types of sensors, that are attached to the TB via 2 screws (used for recalibration also).

p.s. i haven't been able to locate the IAC on my car also, however i didn't remove the TB.

[BigMo82]

Frank, I have connected all the cables and hoses correctly and made sure they are on tightly and securely. Brakes feel fine and they haven't been changed. Brake and clutch fluid is also fine. I haven't checked the intake manifold gasket. That sounds like quite a major job?

Mo

[BigMo82]

Vlado, yes I removed the throttle body completely. Then cleaned it really well. There is no way that any rubbish was left behind. I'm not sure where the idle air control is but it's definitely not attached to the throttle body.

Mo