Toyota 2C-TE 2.0TD 99 Avensis

debabyjesus

Hi all, looking for some knowledge on this engine, having trouble with idle speed. It idles at 600rpm when hot and puts a fairly violent vibration through the car.

It doesn't seem to have any idle speed adjustment screw as its a vacuum controlled throttle afaik.

Is there anyway to raise the idle speed on these? Even bringing it to 625rpm with the pedal the engine is like a mouse's heart.

I tried a service, also took off throttle body and cleaned it, left battery disconnected for a good while and then drove it for 30 mins, still the same idle speed.

Maybe the 600 rpm idle is correct but it seems a bit low to me. When starting from cold it idles perfectly at about 650rpm then fairly quickly drops to 600rpm and shakes the car.

Any input appreciated.

colm_mcm

Temporary measure but turning the fan on increases the revs when cold

ba_barabus

colm_mcm wrote: »

Temporary measure but turning the fan on increases the revs when cold

You should see my gf's one. Start it and it idles as above. Turn the fan on and it starts idling at 1100rpm.

Sometimes it idles right. It's working fine otherwise.

colm_mcm

ba_barabus wrote: »

You should see my gf's one. Start it and it idles as above. Turn the fan on and it starts idling at 1100rpm.

Sometimes it idles right. It's working fine otherwise.

Theyre supposed to do that. Its to heat up the engine quicker

Once engine gets to temp the revs drop again

Later ones had an idle up button IIRC

debabyjesus

It idles at 650 when cold and you'd barely know the engine is running its that smooth. Couple if minutes later it drops to 600 and tries to shake itself out of the car.

I had heard of tricking the ecu into thinking the engine was cold all the time... surely this would lead to overfuelling.

there must be something wrong somewhere as its horribke to sit in at idle...

dgt

What injector pump have you got

debabyjesus

dgt wrote: »

What injector pump have you got

Denso pump not sure if that helps

dgt

debabyjesus wrote: »

Denso pump not sure if that helps

Are there any screws near the throttle arm you can wind in a bit to adjust the idle/anti stall?

I work primarily with ve pumps so a bit unfamiliar here

debabyjesus

dgt wrote: »

Are there any screws near the throttle arm you can wind in a bit to adjust the idle/anti stall?

I work primarily with ve pumps so a bit unfamiliar here

Ya there are a couple of screws on the throttle arm that look like adjustments. Not sure what to do with them though as there are two vacuums on the throttle body too. I know earlier engines you could just adjust idle and max by turning screws but not sure about this set up as there is no throttle cable and its obviously vacuum controlled.

dgt

debabyjesus wrote: »

Ya there are a couple of screws on the throttle arm that look like adjustments. Not sure what to do with them though as there are two vacuums on the throttle body too. I know earlier engines you could just adjust idle and max by turning screws but not sure about this set up as there is no throttle cable and its obviously vacuum controlled.

There's definitely a throttle arm?

Any time I've had to adjust fuelling/idling I've done it live ie when the engine was running to hear the differences/engine note change. That may be your best option

debabyjesus

I'll have another look tomorrow and might take a pic and post it

debabyjesus

Ok so a bit confused how this throttle body works.

if you try rev the engine by moving the 'arm' on the throttle body nothing happens.

if you rev the engine by the pedal the arm also doesnt move until you let off the revs, then it moves a bit and returns to its original position very quickly.

Not sure about this system at all so hopefully someone has some gen.

debabyjesus

Downloaded the toyota workshop manual for the 2C range of engines but of course the 2CTE wasn't in it. All the engines covered in it have cable operated throttles.

There is very little info about this engine online which is unusual. Maybe because it was a europe only engine fitted to very few models and it was half electronic effort between the older 2C's and newer d4d type.

If anyone here could shed any light on the idle control on these or how the accelerator/throttle system works it would be much appreciated.

dgt

If you could get a picture of the pump up that would help

debabyjesus

Found this online,clears up my confusion a bit.

A diesel does not have a "throttle". It has excess air at all times and the speed is controlled by the fuel injected, which has been calculated from the ECU "map" dependent on accelerator position, coolant temperature, air temperature, manifold (or boost) pressure etc etc.
An "air flap" is fitted into the air inlet duct and acts as a safety device in case the engine "runs away" e.g. oil seal failure in the turbo pumping oil into the engine. The flap shuts to starve the air

So now I understand the presence of the butterfly valve in the intake on my td, and why it is fully open practically all the time. I'm obviously getting confused with the purpose of the butterfly valve on a petrol car.

So my low idle problem likely lies with an under-fueling condition, possibly a low voltage being sent from the accelerator position sensor to the ecu or some other sensor out of whack. Maybe a fault with the pump itself.

Luckily I have several donor cars and engines to rob parts from and will probably go for the accelerator position sensor first. It will prob be quicker just to swap it out rather than testing its output voltages. If that doesn't fix it i'll go for ecu or pump next.

debabyjesus

Eventually found the method of adjusting idle speed. The accelerator position sensor potentiometer is on a sliding mount attached to the pedal, just slacken the two 8mm bolts and adjust as necessary. You have to do it with the engine off though as the pedal has another separate position sensor on it and if you move the potentiometer without moving the pedal it goes into safe mode. So bit of a guessing game.

Swapped ecu's aswell for the craic and it was a non runner so ecu must be paired with the pump possibly.

She now ticks over at 750 hot, 900 cold and 1100 cold with fan. Happy days, thanks all.