Idle drops to 400-500rpm when air con is on...

[beeza]

Is this normal?

[CRXer]

No its not normal,it might dip temporarily when the thermostat kicks in but it shouldnt stay there.

sounds like the ECU is not getting the A/C signal to tell it that its on.

Does your A/C get cold once its on?

[beeza]

Yes it does get cold quite quickly.I was having idle issues b4,I cleaned out the TB and it seemed fixed it... but from time to time,not often at all,it dips a bit low.Once I give it a bit of a rev it comes right???
But it definately dips to 400-500rpm when air con is on aswell.

[Fo55il]

weak battery ?

[beeza]

Thanks mate.I'll charge it up and see if it still does it.

[Fo55il]

it could be your batterr is weak/old .
charge it up n check .... if not then try n borrow a newish battery n check your air con ...
if dat dun work then, take it to a mechanic ....
good luck
hopefuly its nothing major

[beeza]

Thanks again mate :)

[xedent]

One of my mates had this problem and turned out to be a faulty ecu, but that was on his corolla.

[Setanta]

ummm - you guys do know that there is an ECU system that increases revs at idle depending on how far the engine is under load right? As pointed out earlier, it could be a faulty relay - my EF9 used to send a signal to the ECU to up the idle when the aircon came on as CRXer pointed out.

lol @ lack of battery charge comments :D

[bennjamin]

ummm - you guys do know that there is an ECU system that increases revs at idle depending on how far the engine is under load right? As pointed out earlier, it could be a faulty relay - my EF9 used to send a signal to the ECU to up the idle when the aircon came on as CRXer pointed out.

lol @ lack of battery charge comments :D


Do they realise if you disconnect the battery while the car is running it wont change anything ? (dont do this lol)

What about weak alternator ? my old eg had a semi-retired alt. and when the AC or headlights went on the RPMS dropped more than usual

[Killa From Manila]

does it drop slightly when u push the brake predal while idle? could be ur iacv, try give that a clean.

[Fo55il]

ummm - you guys do know that there is an ECU system that increases revs at idle depending on how far the engine is under load right? As pointed out earlier, it could be a faulty relay - my EF9 used to send a signal to the ECU to up the idle when the aircon came on as CRXer pointed out.

lol @ lack of battery charge comments :D

appreciate your comment but dun appreciate your mocking - keep dat to yo self .

we were only tryin to help

[beeza]

It dosent drop when I apply the brake.Yeah I cleaned out the TB and IM just recently.I've had a bit of a electrical thing in the car... sometimes/rarely some speakers just cut out then come back etc.It happens a few times then it wont happen for a month then it happens again etc.
I replaced the RCA's,run the power cable down the other side etc.It's a strange one alright.
I just bought the Pivot 5 cable grounding kit.I'll see how it is after installing that.I'll make sure I run one to the alternator.
A weak alternator could be it.It's 11 yrs and 86,000kms old.

[mrwillz]

i fort this was quite normal wen i had air con on in my ek d16y4

[Setanta]

appreciate your comment but dun appreciate your mocking - keep dat to yo self .

we were only tryin to help

Then don't talk shit that you have no idea about. The battery is rarely the issue in this sort of issue.

Using ghetto-speak doesn't make you cool by the way, it just reinforces a ricer image.

[beeza]

Lets not argue,hey.

[Setanta]

Not arguing... yet ;)

BTW, compressors work on engine load, not electricity. The ECU/relay (depending on vintage) bumps the idle to compensate for the physical load.

You need to identify what the system is, relay or ECU. Then you need to check the components (rarely the ECU, especially if your cold-idle is fine in the morning).

[Fo55il]

maybe u should go fix his car then genius -

good luck wid yo car beeza -

nice avatar btw

[beeza]

Thank U.The Aviator,so True huh :)

[Setanta]

OK, after reading through a few troubleshooting manuals, there seems to be two areas that this could lie in. Less likely is the signal to the ECU (but seeing as you have been doing some wiring, you may like to check this), more likely is issues with the EACV (Electronic Air Control Valve). This is generally located to the back of your motor, quite close to the intake manifold. You may or may not have a flashing light sequence on your ECU, I didn't when I replaced the EACV on my EF9. I have a flowchart for checking it but it's 3 pages long, let me know if you want it posted.

I had issues with my EACV and TPS which were unrelated to your AC problem and when I removed it, found it to be faulty. I'm not saying it is the issue, but it's something to consider. They can be removed and cleaned with carby cleaner (at your own risk, I've seen people have no problems doing this but it depends on your mechanical abilities). You'll also want to replace the mounting gasket.

BTW, have you checked all your vacume hoses for leaks?

[Setanta]

Done some additional reading. I'm not sure why the (Honda) manual is pointing to the EACV which is temperature controlled. The issues are more to do with hunting or over-idling. BUT, this is what it has to say:

http://members.iinet.net.au/~setanta/misc/istrouble.jpg

[beeza]

Thanks mate.I have cleaned out my TB and IM with carby cleaner already :)
My problem looks like it's page 64.What does it say?

[Setanta]

Here you go, only problem is it requires a diagnostic tool :S

http://members.iinet.net.au/~setanta/misc/p64.jpg

http://members.iinet.net.au/~setanta/misc/p65.jpg

http://members.iinet.net.au/%7Esetanta/misc/64.jpg

http://members.iinet.net.au/%7Esetanta/misc/64.jpg
http://members.iinet.net.au/%7Esetanta/misc/65.jpg

[beeza]

Awesome.Thanks heaps mate.I'll print out and take it to my mechanic.