Corolla idling very high

dnme

Hi friends, I know I posted something similar to this before but this is a different car and slightly different issue.

I have a 98 Corolla (tilt back). Just bought it. It has just passed NCT and I then had it serviced. Oil, Air filter, correct plugs etc. My mechanic gave it the once over and renewed a couple of pipes as well as taking off the throttle body and giving it a good clean.

Its running fine now except that it idle's high. So, I dont want to spend any more money on this unless I have to for the moment, but I'd dearly love to find the culprit or at lease understand why it's doing this.

Can I ask those of you good/familiar with this particular engine where should I start?

Where do I start?
What if any simple tests can I carry out myself?
Is there an idle sensor? where is it?
Is there a simple way to isolate particular sensors (removed fuses or something like that?)

Pic of engine included, if you mention any sensor to me, can you point out where it is?

I'm sincerely grateful for any help you can give

Plug

Maybe your mechanic didn't put the cable back on the trottle body correctly, though it looks alright.
See can you adjust it. See the rubber pipe that goes from the rocker cover to the inlet manifold well look at the left of it that looks like a little nut you can turn. Do it while the engine is idling and listen.

bigbadbear

I'm not a mechanic but an educated guess would tell me that the screw that holds the throttle open needs to be losened/tightened. The throttle is circled in red in this pic. try it and best of luck.[IMG]file:///C:/Users/Paul/AppData/Local/Temp/moz-screenshot.png[/IMG][IMG]file:///C:/Users/Paul/AppData/Local/Temp/moz-screenshot-1.png[/IMG]

dnme

Plug wrote: »

Maybe your mechanic didn't put the cable back on the trottle body correctly, though it looks alright.
See can you adjust it. See the rubber pipe that goes from the rocker cover to the inlet manifold well look at the left of it that looks like a little nut you can turn. Do it while the engine is idling and listen.

Plug

Are you talking about this?



Thats very tight, he even put some cement between the pipe and manifold(which I aint too happy about but anyway)

dnme

bigbadbear wrote: »

I'm not a mechanic but an educated guess would tell me that the screw that holds the throttle open needs to be losened/tightened. The throttle is circled in red in this pic. try it and best of luck.[IMG]file:///C:/Users/Paul/AppData/Local/Temp/moz-screenshot.png[/IMG][IMG]file:///C:/Users/Paul/AppData/Local/Temp/moz-screenshot-1.png[/IMG]

bbb, throttle is fine but many thanks for the input

Plug

Bottom left, get an open ended spanner on it, possibly 10mm or 12mm.

dnme

Plug wrote: »

Bottom left, get an open ended spanner on it, possibly 10mm or 12mm.

Ok Plug, Ill try to give it a tighten in the morning. I'll let u know how it goes

dnme

Can anyone point out the Idle Air Control (IAC) valve to me on the above image?

Plug

Make sure to do it while the engine is running so you'll know if your turning it the right way. i.e. lower idle.

dnme

Hi Plug,

I get it now, you were asking me to adjust the tension of the throttle cable. It's not that, thats fine and the throttle is returning to its idle position with ease.

I notice today that the idle is not only high, its up and down, particularly when the car is warm. Infact when the car is cold, ts too low and usually the opposite when the car is warm. But its varying up and down when I idle at traffic lights or whatever.

Any suggestions as to where I start with this one?

GTE

gt112 wrote: »

Hi Plug,

I get it now, you were asking me to adjust the tension of the throttle cable. It's not that, thats fine and the throttle is returning to its idle position with ease.

I notice today that the idle is not only high, its up and down, particularly when the car is warm. Infact when the car is cold, ts too low and usually the opposite when the car is warm. But its varying up and down when I idle at traffic lights or whatever.

Any suggestions as to where I start with this one?

I dont know the engine but could a tempreture sensor somewhere becausing the odd idle? Messing with fuel mixtures and what not.

Stoolbend

Try removing the EFI fuse in the fuse box beside the battery for a couple of minutes and see if that helps.
But if engine temp is affecting it it could be a sensor.

dnme

barry81 wrote: »

Try removing the EFI fuse in the fuse box beside the battery for a couple of minutes and see if that helps.
But if engine temp is affecting it it could be a sensor.

I'll try that Barry, can you explain it? what effect will removing EFI fuse have? why? thanks

Stoolbend

It should reset the basic settings.

It's a pretty simple check to try first. But chances are if engine temp affects it, it could be a temp sender as mentioned above.

dnme

Do I pull the EFI fuse while the car is running or with the ignition off? or does it make any difference

mlmcelligott

try cleaning the mass airflow sensor. this sensor regulates the fuel air mix and if it is dirty you would get a false reading and the engine could run sweet

dnme

mlmcelligott wrote: »

try cleaning the mass airflow sensor. this sensor regulates the fuel air mix and if it is dirty you would get a false reading and the engine could run sweet

where is it? can you highlight it on the image?

Stoolbend

Technically the car should be switched off!

mlmcelligott

[/QUOTE]
its on the right hand side of this image on the back of the air box. I dont know how to highlight it on the image.

mlmcelligott

there is also a breather pipe that connects the sump of the engine to the underside of the card body. check that pipe to see if it is blocked with gunk. sometimes if too much oil is put in it can blow back up the pipe and cause the mix to run rich also

dnme

Is this the one you mean?



This was actually left out of its socket for a while before I bought the car, I noticed that one day, I cleaned it with a bit of wd40 and plugged it back in, didn't seem to make much difference, idle was still up and down.

mlmcelligott

no picture attached there

dnme

mlmcelligott wrote: »

no picture attached there

try again, ctrl+f5

mlmcelligott

gt112 wrote: »

try again, ctrl+f5

nah i still cant see what you've highlighted but Id say you know what im talking about. I had a 98 corolla that had a similar problem and it turned out to be the mass air flow sensor. if you take it out there are two pins that stick into the airflow. not sure of the engineering but they can some how measure the mass air flow. see if they are both still in place because one of mine broke off and I can only assume its in the bottom of the throttle body now!

dnme

Can you see it now?



Link:
http://boards.ie/vbulletin/attachment.php?attachmentid=103989&stc=1&d=1264979335

mlmcelligott

gt112 wrote: »

Can you see it now?



Link:
http://boards.ie/vbulletin/attachment.php?attachmentid=103989&stc=1&d=1264979335

yip thats it. why was it disconnected when you got the car? that very well could be the fault.

kermitpwee

The problem is with your throttle body mate. The butterfly spindle is sticking. Options are you can try cleaning out the throttle body with carb cleaner. Cleaning the thottle body works on most makes of cars but in my exp rarely on toyotas. You could get a working throttle body from a scrapper and fit it. The symptoms are low idling on cold start up and then high idling when warm. When its warm it idles between 1200 and 1700 revs. On other makes the high idle would fluctuate between the values i have given but on your corolla I would say the high rev is constant i.e 1500 or so. I cannot understand why your mechanic applied gasket sealer(cement) where he did. Its madness.

JHMEG

Plug wrote: »

Bottom left, get an open ended spanner on it, possibly 10mm or 12mm.

Bottom left is for taking the slack off the accelerator cable.

Top right is for keeping the plastic air pipe attached to the throttle body.

There is an idle adjust screw around the throttle plate but I'd be 99.9% sure it has nothing to do with it.

dnme

Bought it privately recently. Woman owner who's brother / mechanic serviced it. It was off the road for a cpl of years in their garage as they got a new car. He got it going and got it nct'd in January.

dnme

JHMEG wrote: »

Bottom left is for taking the slack off the accelerator cable.

Top right is for keeping the plastic air pipe attached to the throttle body.

There is an idle adjust screw around at the throttle plate but I'd be 99.9% sure it has nothing to do with it.

all the above are fine, but thanks for the input

dnme

kermitpwee wrote: »

The problem is with your throttle body mate. The butterfly spindle is sticking. Options are you can try cleaning out the throttle body with carb cleaner. Cleaning the thottle body works on most makes of cars but in my exp rarely on toyotas. You could get a working throttle body from a scrapper and fit it. The symptoms are low idling on cold start up and then high idling when warm. When its warm it idles between 1200 and 1700 revs.

my mechanic took the throttle body off last week and gave it a good cleaning.

kermitpwee

gt112 wrote: »

my mechanic took the throttle body off last week and gave it a good cleaning.

Was it idling ok before you gave it to him? I'm guessing not if he cleaned it.

dnme

No, it was erratic before i gave it to him. Infact I gave it to him to do timing belt and service and he had a go at sorting out the idle as an extra

kermitpwee

When you say it was erratic what do you mean exactly? On a cold start would it start high(as it should) and get higher to say 2200 revs and jump up and down to 1500 revs and later settle or was it something else?

Who brought the car to the nct?

mlmcelligott

is the choke stuck open?

dnme

when cold starting, it idles low, too low, then when the car warms up it either idles too high or fluctuates up and down.

The previous owner put it through nct.

wrt choke beng stuck open, dunno but doubt it

kermitpwee

mlmcelligott wrote: »

is the choke stuck open?

Automatic choke on these mate via the ecu and throttle body, so thats not it.

mlmcelligott

id still check the maf - heres a link explaining how to test it http://www.askmehelpdesk.com/cars-trucks/testing-mass-air-flow-sensor-159902.html

kermitpwee

gt112 wrote: »

when cold starting, it idles low, too low, then when the car warms up it either idles too high or fluctuates up and down.

The previous owner put it through nct.

wrt choke beng stuck open, dunno but doubt it

There is no way that it could have passed the nct legit if it was doing that so maybe the previous owner knew someone.

Anyway how low is low? Is it idling so low that it sounds like it will cut out? I really do think that its the throttle body mate, provided that the symptoms haven't changed since it was serviced.

martinr5232

On the throttle body there are two coolant pipes going into the bottom of it they work a sort of choke.

That valve is stuck if you take the throttle body off you shoud see it.

Its been a while since I had this problem so I cant really remember exactly what to do.

but I guarantee that is your problem I had the same thing with a car I done a head gasket on It nearly drove me mad trying to sort it.

kermitpwee

martinr5232 wrote: »

On the throttle body there are two coolant pipes going into the bottom of it they work a sort of choke.

That valve is stuck if you take the throttle body off you shoud see it.

Its been a while since I had this problem so I cant really remember exactly what to do.

but I guarantee that is your problem I had the same thing with a car I done a head gasket on It nearly drove me mad trying to sort it.

Thats interesting. Is the valve in the actual body of the throttle or is it in the outlets that the coolant pipes attach to?

jimmyw

Sister had a problem with idling on a 99 avensis and I tried to remove I think the idling control, its underneath the TB anyway and I could'nt and f****d it up. I got one from a scrappy and fitted it (dead easy) and its still doing it a little like idling too slow when cold, and racing when hot. It used to smoke and nearly cut out when cold, but its not too bad now but still not as it should be. I thought it might be the temp sensor, but when I disconnected the wire to it, the rad fan came on and stopped when it was reconnected.???????

martinr5232

kermitpwee wrote: »

Thats interesting. Is the valve in the actual body of the throttle or is it in the outlets that the coolant pipes attach to?

I cant rightly remember its about three years since ive seen this problem.

I think at the bottom of the throttle body there is a valve that bolts on to it with two coolant pipes going into it this valve then works a type of butterfly in the throttle body it is this that is seized.

It is hard to explain without seeing it again.

kermitpwee

martinr5232 wrote: »

I cant rightly remember its about three years since ive seen this problem.

I think at the bottom of the throttle body there is a valve that bolts on to it with two coolant pipes going into it this valve then works a type of butterfly in the throttle body it is this that is seized.

It is hard to explain without seeing it again.

No i get ya. I know the unit alrite, must have a look at one.
Thanks

mlmcelligott

any update on the car for us? did any of that advice work?

Leonard Hofstadter

mlmcelligott wrote: »

is the choke stuck open?

Fuel injected cars don't have chokes.

dnme

I am nowhere near confident enough to carry out any of the work suggested folks. I would wreck it, trust me and I dont have tools etc.

My own mechanic has already had a go, and remember he's the one who put gasket cement around the air intake pipe etc so I am reluictant to go back to him.

So, wrt updates? I dunno what to do
does anyone knoe a good decent "HONEST" mechanic in or around Galway? that I could bring this to?

dnme

guys,

just found a recon throttle body for a corolla on ebay for 45 quid. Do you think it a good idea that I buy it and bring the car and part to as decent mechanic?

martinr5232

Do what I suggested first it will save you money even if you cant do it yourself get someone to do it for you it only takes half an hour.

If you want anymore info just ask!

dnme

martinr5232 wrote: »

Do what I suggested first it will save you money even if you cant do it yourself get someone to do it for you it only takes half an hour.

If you want anymore info just ask!

Thanks for that, but I have no tools, and I assume that even if I took the throttle body off, I would need gaskets to put it back on, so therefore I would have to go to a mechanic again anyway