106 1.1 rough idle - Saxperience

Cleme1995 · 10th November 2021, 15:44

Hi everyone

I'm currently new to the forum and in need of a bit of help regarding a Peugeot 106. I appreciate this forum is for saxo however I have tried the Peugeot forums with now luck ( don't think any are live anymore) so I was hoping one of you guys could possibly help me with this problem.
I purchased this car very cheap a few months ago it just passed it's Mot however it has a problem when it idles the car surges and the rev counter will bounce up and down not by much but noticeable. I have noticed it usually does it once the cars up to normal temperature but I'm guess thing that could be because the engine is revving slightly more anyway due to it being cold? So I've changed the idle control/stepper motor, i've cleaned the throttle body butterfly and checked the hoses for vacuumleaks, also changed he spark plugs aswell all to no avail... I've noticed that it is slightly worse when coming to a stop and then once stopped it seems to settle for a few seconds and then with start revving up and down again and also it gets more erratic when I'm reversing.
Any help would be much appreciated.

Thank you

Chipwizards · 10th November 2021, 19:07

See if it stops doing it with the lambda sensor unplugged.
If it stops surging, it's probably just because the control loop is going rich/lean, with the engine slowing down when it's lean.
It MIGHT be improved with a new lambda sensor, because when they get old they get slow. A slow sensor causes a larger hysteresis, so the engine goes leaner than it should, then goes richer than it should, before the lambda responds, causing speed variations.

Cleme1995 · 10th November 2021, 20:36

Okay I will try that mate I have unplugged the icv/stepper motor and this does make the engine run perfect but as soon as it's plugged back in it starts doing it again... I will try what you've said tomorrow hopefully in the light!

Chipwizards · 11th November 2021, 20:04

It could also be that the idle speed is too high, for whatever reason, and when it gets as high as the decel cut-off it turns the injector off and back on when it returns to the idle speed.

Cleme1995 · 11th November 2021, 21:10

Is there anyway to adjust that? I find it strange that unplugging the icv the problem disappears? Or would that be normal?

Cleme1995 · 18th December 2021, 20:26

Hi just an update as it's been a while. I've since changed coilpack and another icv just incase the last was faulty done the reset still the same
. However I've done a scan with a cheap ob scanner and these 2 codes came up

P1523 manufacturer control
P1327 manufacturer control

After researching one is a ivc solenoid malfunction ( no idea how to test and repair)

The other I'm not so sure. I've cleared and nothing has came back just yet however the rough idle etc still carries on being a nightmare

Chipwizards · 18th December 2021, 21:52

Quote:

Originally Posted by Cleme1995

Is there anyway to adjust that? I find it strange that unplugging the icv the problem disappears? Or would that be normal?

Unplugging it also disconnects the 'closed throttle switch', so it then doesn't do the overrun cut. I would expect it to do that.

Either the idle stepper is wound out too far/broken/wiring issue etc, or there's an air leak causing a fast idle.

Cleme1995 · 18th December 2021, 22:30

seeing as it brand new and it wasn't too far out at first is there a way of pushing it back in and then learning its new position again? i did notice the one i took off was quite a bit further out than the new one putting it in. i did disconnect the battery for a good few hours after to reset the ecu. also regarding testing the wiring is there a way to do that with the multi meter? i always struggle to know which colour wires i need to be on? thanks in advance I'm really hoping to get this fixed.

MartinObviously · 20th December 2021, 03:05

Quote:

Originally Posted by Cleme1995

Hi just an update as it's been a while. I've since changed coilpack and another icv just incase the last was faulty done the reset still the same
. However I've done a scan with a cheap ob scanner and these 2 codes came up

P1523 manufacturer control
P1327 manufacturer control

After researching one is a ivc solenoid malfunction ( no idea how to test and repair)

The other I'm not so sure. I've cleared and nothing has came back just yet however the rough idle etc still carries on being a nightmare

P1523 appears to be ICV circuit malfunction.

I'm going to make a really dumb assumption that the 1.1 3 plug ECU is the same Bosch unit as my 16v ECU. Your ECU has 3 plugs, Brown, black and grey. They have numbers and letters to each plug to identify. The wiring colour can vary but they all have 4 digit identifications.

On the Grey 36 pin plug:

E3 goes to pin A on the ICV plug, should be a white wire (1244)
D2 goes to pin B on the ICV plug, should be a red wire (1245)
D3 goes to pin C on the ICV plug, should be a Yellow wire (1246)
D1 goes to pin D on the ICV plug, should be a Green wire (1247)

Use a thin piece of wire to put down the plug if your multimeter doesn't have the correct attachment, don't force a pin that's too big down there. The distance is small I would expect the resistance to be almost 0 ohms.

The ICV housing has to be cleaner than a laboratory, sometimes a bit of grease helps. Also non genuine ICV are problematic, I could only fix mine with a genuine item from the dealer

P1327 is phase detection from your coil pack, some scanners will say it is a camshaft sensor. Later models with the Bosch 3 plug ECU use the coil pack to detect the cylinder which has just fired so that it can run sequential fuel injection. The coil pack you have fitted is from an older model and isn't fully compatible. This shouldn't affect the idle, as the ECU will just run fuel injectors in batch.

the ICV learns itself very quickly, there's no reset procedure for it, don't force it into its housing