Idle dropping when warm

A

AlexGTR

Member +
Hi Guys,

I've had this issue since i bought the car and it seems to be on off.

When the engine is warm and i am coming to a stop, the revs will drop to around 200-300rpm and sit there till i come to a stop and then slowly go back up if i'm lucky. It was cutting out quite a lot as well when it was doing this but has stopped since i reset the ECU.

Does anyone have any ideas? Its doing my head in.

I have put in a new Dizzy and rotator arm and also replaced the leads with known working ones and it has made no difference other than sort out a misfire that i had.

I guess the next thing to do would be to clean the ICV but are there any other thing I can check?
 
M

milly420

Fresh Recruit
does it happen when you are breaking? because my ep82 kept on cutting out when coming to a stop it was a faulty break servo. put the car in neutral while running and keep pressing breaks and se if engine dies hope this helps
:rockon:
 
Last edited:
A

AlexGTR

Member +
milly420 said:
does it happen when you are breaking? because my ep82 kept on cutting out when coming to a stop it was a faulty break servo. put the car in neutral while running and keep pressing breaks and se if engine dies hope this helps
:rockon:
Click to expand...

Thanks for the reply.

No it doesn't its only when your coming to a stop then put your foot on the clutch.
 
A

AdamB

Member +
You could try checking the wax stat in the throttle body. Not 100% sure but once the coolant is warm through the throttle body it obviously opens up the wax stat. I'm sure it allows a bypass of air through the the idle control valve, but don't quote me on it.
 
Texx

Texx

Super Moderator
Can you hear the idle control valve clicking when the engine is at idle? (Should be a fairly loud ticking noise that stops as the throttle pedal is pressed)

If you can't hear the idle control valve then either it's not working or you have a problem with the idle switch in the throttle position sensor.
 
A

AlexGTR

Member +
AdamB said:
You could try checking the wax stat in the throttle body. Not 100% sure but once the coolant is warm through the throttle body it obviously opens up the wax stat. I'm sure it allows a bypass of air through the the idle control valve, but don't quote me on it.
Click to expand...

What does that look like/how do i check it?

Texx said:
Can you hear the idle control valve clicking when the engine is at idle? (Should be a fairly loud ticking noise that stops as the throttle pedal is pressed)

If you can't hear the idle control valve then either it's not working or you have a problem with the idle switch in the throttle position sensor.
Click to expand...

I have noticed a loud clicking when the engine is idle, i will check properly tomorrow.
 
A

AlexGTR

Member +
I checked the engine this morning after driving to work and the only clicking i could hear sounded like the injectors, which got faster as i revved the engine a bit. Could that possibly mean its the ICV? How can i check the idle switch in the TPS?
 
cheshireglanza

cheshireglanza

**Do not buy from me**
The clicking is your injectors have you tried the idle control valve try screwing it out so the idle goes up to about 1k revs when engine is warm
 
corofin12345

corofin12345

Member +
cheshireglanza said:
The clicking is your injectors have you tried the idle control valve try screwing it out so the idle goes up to about 1k revs when engine is warm
Click to expand...

thats not the idle control valve.. thats the idle screw..

id start by taking apart and cleaning your ICV which is mounted to the left hand side of the inlet manifold...
 
A

AlexGTR

Member +
Do you pull the plug when the car is off or on? last time i pulled it out it cut the engine out, is that right?
 
A

AlexGTR

Member +
Ok, removed the icv and cleaned it that made no difference. Also linked the bottom too connections in the tps plug and it made my idleget worse. Anyone got any other ideas?
 
A

AlexGTR

Member +
Shaneyb said:
If it revs normal when the engine is cold then its most likely the ICV that needs replacing.
Click to expand...

Yeah car drives and revs fine on cold start, its once the revs drop after it gets upto temp.

I will ask my mate to borrow his icv and see if it makes difference.
 
A

AlexGTR

Member +
milly420 said:
does it happen when you are breaking? because my ep82 kept on cutting out when coming to a stop it was a faulty break servo. put the car in neutral while running and keep pressing breaks and se if engine dies hope this helps
:rockon:
Click to expand...

I did this yesterday and the revs did drop a bit, is that meant to happen? The car drop the revs enough to cut out, maybe 100rpm max.
 
wildchild

wildchild

Member +
maybe your throttle valve is stuck. try spraying some injector cleaner or something thats good to clean the valve.
btw TEXX and WEEJOHN have done some excellent work! thumbs up to both of u guys.
 
weeJohn

weeJohn

Lifer
Ok, sounds like the TPS is not set correctly, there should be no change in idle speed with the bottom 2 wires of the plug linked out when at idle. Another thing that can affect this is the wax stat that is built into the throttle body. Its purpose is to allow more air to bypass the throttle plate when its closed when the engine is cold, which is needed for cold running. Inside the mouth of the throttle body, before the plate and on the bottom there is a hole about 5mm in diameter, this is where the air comes into the wax stat and gets by passed round the plate.

Another thing you may need to check is the throttle stop screw has not been moved, the plate in the throttle body should be just closed when the cable cam hits the screw, it may take a little bit of adjusting between this and the idle air screw to get a decent idle speed. If doing this I would put that link back in as adjusting the screw adjusts the TPS.
 
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