172 cuts out at low RPM

[Luca.smr125]

Hello, my 172 ph2 is cutting out when im driving away from a stop or when im driving out of a hairpin turn at 2nd gear. It doesent happen all the time tho.

My father pointed out that it could be a faulty Lambda sensor or that the engine needs some run time again because it was stationary for 4 Years.

 

[Luca.smr125]

It only accurs when the engine gets below 2000 RPM and dissapears after that. I dont think that its a lambda because it feels more like a ignition problem. Im looking forward to order some Coils, Cabels and new Plugs and if it doesent dissapear then continue the search.

 

[Darren S]

Have you checked the air filter area too? All clean and not clogged?

 

[cjgower]

Could be the MAP sensor. Is it secure against the manifold? may even be worth trying that first.

If there's no misfire, throwing money at ignition related items seems a waste. I may be wrong.

 

[Luca.smr125]

Have you checked the air filter area too? All clean and not clogged?

Yes the airfilter is fine

 

[Luca.smr125]

Could be the MAP sensor. Is it secure against the manifold? may even be worth trying that first.

If there's no misfire, throwing money at ignition related items seems a waste. I may be wrong.

You can hear it abit from the exhaust. But the Plugs, Coilpack and the Wires look fine. Im gonna take apart it more and see if i can reach the MAP sensor

 

[Alex82]

Have you tried the PAS sensor, can cause it to cutout at low rpm, when idling and stationary turn the steering side to side, rpm should go up.

 

[Luca.smr125]

Have you tried the PAS sensor, can cause it to cutout at low rpm, when idling and stationary turn the steering side to side, rpm should go up.

Yes when i turn the steering wheel the rpm needle moves. Its the pas sensor from the gas?

 

[Ash007ks]

Was there fuel within the car when you left it to sit for 4 years ?

 

[Luca.smr125]

Was there fuel within the car when you left it to sit for 4 years ?

I think not. When i picked it up the tank was allmost empty.

 

[Ash007ks]

Try getting some decent fuel through it , super unleaded. Then clean the sensors up. You can get to the main ones no problem. Happy to take a pick under my bonnet tomorrow if you get stuck.

Also check your throttle body butterfly. The opening and closing part. Make sure it'd not sticking and give it a clean.

 

[Luca.smr125]

Try getting some decent fuel through it , super unleaded. Then clean the sensors up. You can get to the main ones no problem. Happy to take a pick under my bonnet tomorrow if you get stuck.

Also check your throttle body butterfly. The opening and closing part. Make sure it'd not sticking and give it a clean.

I got like 2-3 Tanks of 98 RON trough it now. But then i try to clean the sensors. Just the one that i can reach or also other ones?

 

[Ash007ks]

I got like 2-3 Tanks of 98 RON trough it now. But then i try to clean the sensors. Just the one that i can reach or also other ones?

I'll grab a photo of what I would clean.

 

[Luca.smr125]

I'll grab a photo of what I would clean.

thank you. This weekend im taking it apart

 

[Luca.smr125]

I'll grab a photo of what I would clean.

Still not running fine

 

[Ash007ks]

Check these two as boy can give poor running. The left hand side one is particularly problematic and as such a few people have created a work around to make sure it doesn't move when driving. The oil ring generally loses the ability to hold it in especially when cornering. ( clean it up and then either replace the O rings with generic size 13mm and 6mm I believe off top of my head or as a temp fix cable tie it and see if the problems go away)

By not running what are your symptoms.

 

[Luca.smr125]

Check these two as boy can give poor running. The left hand side one is particularly problematic and as such a few people have created a work around to make sure it doesn't move when driving. The oil ring generally loses the ability to hold it in especially when cornering. ( clean it up and then either replace the O rings with generic size 13mm and 6mm I believe off top of my head or as a temp fix cable tie it and see if the problems go away)

By not running what are your symptoms.

If you go close to the exhaust you hear its not runnint 100% clean. + if the rpm drops below 2000 rpm its boging until above 2000 rpm above its running fine.

I replaced all the Injectors to check that but it not changed. Also done some modifications to the airbox and removed the heat exchanger👍

 

[Ash007ks]

Have you got a video of it running.

 

[Ash007ks]

Have you seated the inlet properly on its seat. If it isn't seated properly on the the rocker, it causes an air leak and high idle.

Also the pipe around the back of the engine to the right hand side can also cause an air leak leading to high rpm.

Sounds like you may need abit of brake cleaner and spray it onto any inlet pipes and see if the rpms change if your sure you've tightened everything up.

 

[Luca.smr125]

Have you seated the inlet properly on its seat. If it isn't seated properly on the the rocker, it causes an air leak and high idle.

Also the pipe around the back of the engine to the right hand side can also cause an air leak leading to high rpm.

Sounds like you may need abit of brake cleaner and spray it onto any inlet pipes and see if the rpms change if your sure you've tightened everything up.

I dont have high rpm‘s but i will clean those. 2 sensors tomorrow. They feel very loose when i looked at them before. i could wiggle them around. Whats the method of fixating them?

 

[Ash007ks]

Ah sorry I thought you had high idle rpms.

What have you changed and has it ever ran right ?

CFAB makes a map sensor holder , but you can either get generic O rings or get the spares from Renault.

 

[Luca.smr125]

Ah sorry I thought you had high idle rpms.

What have you changed and has it ever ran right ?

CFAB makes a map sensor holder , but you can either get generic O rings or get the spares from Renault.

Yes im daily driving the car. its just not running perfectly fine. I think ill pickup some new Orings then. I changed nothing really

 

[Ash007ks]

Try cable tieing it before you spend money on it. Halfords do an O ring kit , I've had mine years and ocassional comes in handy for stuff like this 😂

 

[Luca.smr125]

Try cable tieing it before you spend money on it. Halfords do an O ring kit , I've had mine years and ocassional comes in handy for stuff like this 😂

Where would you mount the cable tie? Because i cant think of where to put it so it holds the sensor in place. And you still want a video of it running

 

[Ash007ks]

Pop one on here as it may help diagnose it. Certainly if I can't help you I'm sure some other can.

The cable tie would have to go over and through the first inlet , it will look a mess but it was just to diagnose your issue. I didn't actually go that route , as I said I had some halfords O rings kicking about from a kit from years ago. Mine was mega loose to the point you could move it side to side.

 

[Luca.smr125]

Here is a idle and driving video

 

[Luca.smr125]

Pop one on here as it may help diagnose it. Certainly if I can't help you I'm sure some other can.

The cable tie would have to go over and through the first inlet , it will look a mess but it was just to diagnose your issue. I didn't actually go that route , as I said I had some halfords O rings kicking about from a kit from years ago. Mine was mega loose to the point you could move it side to side.

I got like 10 O-Rings. Size 6mm 7mm and 12mm 13 mm that are 2.0 and 2.5 mm thick.

I read in another post that its a 7mm. Im gonna test out

My sensor looks like this to do you think it has the Orings underneath

 

[Luca.smr125]

Pop one on here as it may help diagnose it. Certainly if I can't help you I'm sure some other can.

The cable tie would have to go over and through the first inlet , it will look a mess but it was just to diagnose your issue. I didn't actually go that route , as I said I had some halfords O rings kicking about from a kit from years ago. Mine was mega loose to the point you could move it side to side.

So i tried to cabletie it and use Ductape but it didnt help… Im replacing the Ignition cables. A friend of mine’s dad had the same thing on a 197 and that helped

 

[Luca.smr125]

Pop one on here as it may help diagnose it. Certainly if I can't help you I'm sure some other can.

The cable tie would have to go over and through the first inlet , it will look a mess but it was just to diagnose your issue. I didn't actually go that route , as I said I had some halfords O rings kicking about from a kit from years ago. Mine was mega loose to the point you could move it side to side.

Is that to loose?

 

[Luca.smr125]

ITS FIXEX I CHANGED THE SPARKPLUGS + CABLES

 

[Ash007ks]

Before you changed them did you check which it was ?

I've had two leads go down before, but never all the leads.

 

[Luca.smr125]

Before you changed them did you check which it was ?

I've had two leads go down before, but never all the leads.

Not really, just taken the manifold of swaped plugs and cable and it worked