Hot and cold idle problems?

10th May 2015, 19:41

First of all, sorry if this has been discussed before, ive been looking on here for months now but can't find any thread with the exact same issues im having.

Anyway, ill try to keep this as short as possible...

Car details: Saxo W reg (2000), 1.1 sx, HDZ SPI engine, 55K.

Basically i'm having some issues with idle speed on my saxo. When i start from cold, it runs fine but idles a bit high i would say about 1100 rpm, which steadily drops as the engine warms up. After the engine has warmed up the idle then sort of bounces around 850 to as low as 500 sometimes, feels really lumpy and car shakes a bit, but it has never conked out.

Also if i hold the revs at say 2500 rpm, or when engine breaking and sometimes changing gear i can hear pops and slight bangs.

I have changed the idle control stepper motor for a new genuine bosch one, and done a basic service (oil, spark plugs, air filter, coolant change)

Also recently changed the timing belt and water pump + tensioner allthough i've had these idle issues since i got the car about 8 months a go.

My questions are: Is this just normal?, Could it be the lambda sensor?

Im thinking this could be overfueling

Thanks for looking and if you read this far, i thank you again.

Cheers, Scott

10th May 2015, 19:47

Could be the carbon canister underneath the drivers wing

10th May 2015, 19:56

Never known any problems relating to the charcoal canister before?
Will be a sensor. Lambda could be, have you tried resetting the idle valve?

Sent from my iPhone using Tapatalk

10th May 2015, 20:04

Thanks for the response, ill check this out tomorrow, what would i be looking for, bad piping?. And can the canister just be replaced?

Cheers again, Scott

10th May 2015, 20:08

hey jbrady thanks for replying, by resetting the idle valve do you mean the "turning ignition on and off 7 times" or something like that? I remember seeing that procedure on here when i first swapped the stepper motor. I did do this but don't actually know if it did anything..

10th May 2015, 20:16

I had the same sort of problem with my 1.1 I had years back. Idle kept fluctuating and just wouldn't idle properly. I changed everything on that poxy car even the whole inlet manifold! Turned out to be a lug broke of the carbon canister that a pipe goes into which was causing the idle fluctuations I changed that and it ran spot on.

10th May 2015, 20:20

Milney, that was my next step actually lol, replace the whole throttle body and inlet manifold!. there are so many things the bad idle could be related to, it's really annoying me now.

10th May 2015, 20:23

Yeah I know what you mean was a complete pain in the arse to solve mine. Have a look at the canister and see if it looks ok. Another way of checking it which can sometimes work is where the pipe comes round out of the canister and connects to the inlet manifold unplug it and block it off with your finger or something and start it up and see if it solves your problem. If it does you know the canister is shot.

10th May 2015, 20:29

Ok mate, thanks for the help, ill report back tomorrow eve and let you know the results.

By the way, just thought i'd mention, i ran the car from cold to hot the other day for test purposes with the lambda sensor disconnected from the wiring loom. No engine management light came on (dont know if its supposed to) and its ran EXACTLY the same as when connected.

Any other suggestions are welcome.

Cheers

10th May 2015, 20:35

Yeah let me know how you get on. I hope it is the canister as it's an easy fix for you.
Okay the eml comes on after a certain amount of mileage I think.

11th May 2015, 19:00

Hi all...so i located the charcoal filter and purge valve and did some tests as Milney suggested.

First i disconnected the pipe that ran from the purge valve to the inlet manifold...It ran like crap when i disconnected the pipe (revs up and down, popping really bad) then it conked out.

So i re started the engine but this time blocked off the pipe going to the inlet manifold.. and it ran "normally" as if i had made no changes.

I then realised that there could be a few possibilities: pipe blockage at some point from fuel tank to purge valve?, Purge valve stuck closed? or charcoal filter failure.

Either way i dont have the time because of work to be more exstensive until thursday (day off).

Just a little update. And cheers milney

, feels like i might be getting somewhere.

28th May 2015, 18:36

UPDATE:

Still got the issue when hot here is what i have done so far.

Purge valve and charcoal filter checked - working fine.
Cleaned out throttle body.
Full service *bosch plugs, fresh oil, oil filter, air filter, fuel filter, coolant renewal*
New coolant temperature sensor *green one*
New lambda sensor

There are NO signs of head gasket failure i have checked for Milky oil, oil in coolant, white smoke from exhaust, excessive water from exhaust. Everything is as it should be.

I just don't know what to do next. Any ideas???

Also I have a video of the idle while the car is hot which I can e-mail to anyone who is interested.

28th May 2015, 22:01

Is this a newer style? did you change the right lambda sensor? upstream one causes misfiring.

OR heat breaks down coil packs. So if it runs mint cold, then gradually worse as it heats up that would definitely be worth a punt. maybe find a cheap second hand one to try first before buying new?

29th May 2015, 09:52

Thanks for the reply, mine only has one lambda sensor which is situated before the cat, near the top if the downpipe.

It definitely runs mint when cold and gets worse when hot. I think the coil pack is my next change then. Thanks for the info

29th May 2015, 10:29

I see you have changed the stepper motor what about the icv valve?
I have a (2002), 1.1i sx, HDZ SPI engine, 102K and mine does the symptoms you have claening the valve solves it for a few months (i need a new genuine one really)

29th May 2015, 17:17

Quote:

Originally Posted by vincent1

I see you have changed the stepper motor what about the icv valve?
I have a (2002), 1.1i sx, HDZ SPI engine, 102K and mine does the symptoms you have claening the valve solves it for a few months (i need a new genuine one really)

ICV valve is a stepper motor.

30th May 2015, 11:55

Might be worth contacting Citroen about an ECU update as mine needs one apparently cos a lot of cars weren't done..

Mines in on Thursday for an update..

30th May 2015, 12:31

is there two on a 2002 model? theres the top one with a plunger inside and then the other is like a motor underneath it both diffrent wiring plugs

30th May 2015, 12:43

Quote:

Originally Posted by vincent1

is there two on a 2002 model? theres the top one with a plunger inside and then the other is like a motor underneath it both diffrent wiring plugs

No.

The stepper motor is an ICV. that's the top one with the "plunger". It's a 4 pin connector.

The one below it is the throttle position sensor, it's a variable resistor. it has a 3 pin connector. The connector shape is different to earlier models.

30th May 2015, 13:14

Quote:

Originally Posted by MartinObviously

No.

The stepper motor is an ICV. that's the top one with the "plunger". It's a 4 pin connector.

The one below it is the throttle position sensor, it's a variable resistor. it has a 3 pin connector. The connector shape is different to earlier models.

Thanks martin for clearing that up im new to a saxo too sa all info is good to know.

30th May 2015, 18:12

Quote:

Originally Posted by vincent1

Thanks martin for clearing that up im new to a saxo too sa all info is good to know.

In case you ask what the 2 pin black sensor is on the throttle body at the top, NOBODY knows

The white 2 pin one at the bottom is air temp.

31st May 2015, 20:59

OK update: Changed coil pack for a new one, problem still there. So, fed up and pissed off with this stupid problem I decided to remove the inlet manifold and throttle body....which was a pain in the arse.

Anyway, cleaned the whole thing with carb cleaner and some rags, i must admit it was pretty gunked up with soot and carbon deposits especially in cylinders 2 and 4 for some reason.

Cleaned every single breather tube and solenoid with the carb cleaner, made sure everything was re connected correctly and renewed coolant with some decent stuff.

....RUNS MUCH BETTER. Still very slightly lumpy when hot but on the whole, a big difference.

It was probably an air leak in the inlet gasket seal somewhere..

So thanks to everyone for all the help on here, everybody's replies contributed and in the end, problem solved.