172 not 100% starting right.

[Sjdickso]

Our mk2 172 has just started to not start 100% after it has been sat over night. It does fire up but seems to struggle.

It had a new bat on about amonth ago.

It is due a service so may get the garage to do the plugs as well as the normal filters etc.

Is there anything else (common fault) that may cause this.

Also it went on a RR recently and the service / abs light seems to take longer then normal to go out after a start, should i clear the ECU by disconecting the bat?

Thanks

 

[W111ALG]

Common problem for starting is TDC sensor failure.

 

[AhmedRSi]

My mk2ph1 1.2 8v does this as well, eventually always starts... but it seems to struggle occasionally, often turning over for ages before it actually fires up.

How expensive is a TDC sensor to change?

 

[W111ALG]

I'm not sure about 1.2 but on the 172 its a known problem, I think it was maybe something they changed the desigm on eventually and older ones were perhaps supposed to get fixed under warranty by Reno. If you do a search theres lots of posts on it! They are not that expensive or difficult to change. They are located under the Battery tray. (On the 2L)

 

[AhmedRSi]

Oh ok cool, if anyone knows anything else about the TDC sensor on my clio i would appreciate help

 

[SkidMarx]

Yea make sure you get the modified connector also, bout £50 for the pair. There are many other not so common starting faults also.

 

[AhmedRSi]

Whats the modified connector? i was thinking of just giving mine a clean

 

[Wizbit]

I thought the TDC sensor would be a start / not start issue. Mine went a few weeks ago and there was no sign of it happening. It either started or it didn't - no in between.

The modified connector is a different plug (the blue plug) that needs replacing as the connector on the actual sensor itself was changed at some point by Renault. As davidmellors said, they are about £25 for each part.



When was the car last serviced? Could be spark plugs? Also, what fuel is being used?

 

[SkidMarx]

^^ TDC faults can sometimes make starting hard when the engine is hot.. its not always as simple as it will start or it wont. My TDC sensor failed, would crank the engine for ages and it wouldnt start, when i rolled it down a hill it would bump start straight away :S Changed TDC and connector and it never happened again.. well strange.

Other things to check are the relays next to the battery in the engine bay. There are 3 black relays ( fuel pump, injection computer supply, and starter motor i think ) The relay terminals corrode someties and cause intermittant probs.

 

[Sjdickso]

I will have a look at this TDC sensor.

As said it needs a service.

Would the TDC show up as a fault with fault reader?

It starts first time, it just doesnt leap into life, as it fires the revs fluctuate and feels like it is going to stall, it only does this after it has been sat all night.

It is always run on optimax or v-power.

 

[Christophe]

Mine does exactly the same thing!!!

Every morning it struggles to start. I have to blip the revs to get it going. After that its fine all day. I'v had new battery about 3 months ago and had lambda sensor replaced and throttle bodies cleaned.

I think it could be TDC sensor aswell but not sure as it been on diagnostics but no faults have come up.

 

[Wizbit]

Would the TDC show up as a fault with fault reader?

Apparently not - according to Renault.

It starts first time, it just doesnt leap into life, as it fires the revs fluctuate and feels like it is going to stall, it only does this after it has been sat all night.

It is always run on optimax or v-power.

Mine is exactly the same: Run solely on V-power for months / Starts first time / Revs drop when started in the morning / Quick blip and it's fine until it is stood for a while again.

It has done it this for ages - since using only V-power I reckon! Was serviced in April - made no difference. As I said, just had TDC sensor replaced - made no difference. Green air filter installed - made no difference.

Car has done 78k now - and I am behind with my service schedule, so plugs will be changed next time round as they have been in about 35k.

 

[Sjdickso]

It is getting serviced in a couple of weeks and will have new plugs in at the same time.

I will let you know how i get on then.

I may also try some different fuel.