Help needed regarding my 172.

[FRED172]

Hi Everyone, my name is Fred and I bought a 172 4 weeks ago. have really enjoyed owning it so far. I've had 106 gti's a VTS and in every respect I have got to say I much prefer the 172.

However I have got a problem that seems to have only started in the last few days. When I dip the clutch to come to a stop and am free wheeling the car sometimes stalls. It pretty much happens everytime I take the car out, and seems to happen more often when I am steering at the same time.

Any help advice would be much appreciated! Surely this has happened to someone else.

 

[Russ_16v]

hi and welcome mate

thats nothing iv personally come caross, how old is your 172?

 

[philis]

Sounds like a fuel starvation problem to me, im no mechanic tho.

 

[Edd]

The revs on mine sometimes dip to around 5/600 at the lights.

 

[FRED172]

Every time I stop it dips to around 500, maybe lower. But then sometimes it does actually cut out.

It's an 02 172, 82k, FSH.

Thought this must have happened to someone before?

 

[meady100]

I know about as much about car mechanics as I do flying spacecraft, but maybe the clutch isnt fully disengaging, so that when you brake to a stop, it pulls the engine to a stop too?!

 

[FRED172]

I know about as much about car mechanics as I do flying spacecraft, but maybe the clutch isnt fully disengaging, so that when you brake to a stop, it pulls the engine to a stop too?!

You think maybe the clutch could be slipping, I'll try setting off in 5th and see if I can make it slip.

I don't think it is the clutch though, could it be idle regulator? coil pack? HT leads? It had new plugs about 3 months ago at its last service so shouldn't be them.

 

[Edd]

Where is the idle control valve on a 172?

 

[Nick_P]

Near the throttle body

 

[Russ_16v]

its a PH2 so no ICV so to speak, could be a FBW throttle fault, as they can play up, have you had it plugged in to see for any fault codes mate?

Wont be clutch causing that, so don't worry about that bit

wont be coil if it drives fine and only problem is revs dipping either

 

[shadowsun]

Did you buy it from a dealer or private? If so surely you could claim this under warranty? Worth a try?

 

[MATT BLACK]

TDC sensor
ISCV
Throttle body

A few idea's to point you in the right direction

 

[matthewsimone]

wont be fuel starvation as drives ok and if was fuel it would be the other way round, would probably idle fine but cut out once revs were up and the demand for fuel is higher etc as already said mete sounds like a idle valve/sensor or similar so id get it plugged in 1st before replacing any parts

 

[FRED172]

Thanks for the replys guys, it is much appreciated.

It was a private sale, sold as seen, so no warranty I'm affraid.

I'll most likely be getting it plugged into diagnostics on Saturday.

Back to the problem. I have noticed it only cuts out once the engine is warm and it does only seem to do it when steering and clutch pedal depressed. But in general the Idle is low, 5/600 revs at standing. It may just be my imagination and through driving other cars at work, but the steering in general feels heavier that previously.

What should be the first thing I do, take the Throttle body off and give it a clean or is it better to just get a replacement?

Finally could someone give me any more infor on the following? Price/Location/Part availablity?

TDC sensor
ISCV

Thanks again.

Fred

 

[DrR]

I'd try cleaning the trottle body.

 

[FRED172]

Whats the best think to clean it with? Is it an easy job to take off?

Any more info on TDC/ISCV?

Cheers!

 

[FRED172]

Does a PH2 172 even have an ISCV?

 

[Edd]

Russ_16v states above that the PH2 doesn't have an ICV. So looks like you schould just focus on the throttle body and this TDC.

 

[Goders172]

I had this a few weeks ago took it to a specialist, they put in on the diagnostics and it showed no fault codes. They cleaned the throttle body and ran some fuel cleaner through it and its now (touch Wood) fine. Ive done almost 700 miles since with no probs it was stalling at every junction before hand. Would be worth a try putting some cleaner through before doing anything more expensive. Mine feels like a different car since, it has made a big difference.

 

[FRED172]

Fuel cleaner, is that just redex then? Or is there something out there abit better?

 

[Goders172]

Not sure what they used but i guess redex would be fine.

 

[FRED172]

But did they actually take the throttle body off and clean it? Do you mind me asking what they charged for this?

 

[n00ber420]

my 325i used to do this, pissed me right off.
took the s**t cone filter out and cleaned the airflow sensor..replaced with a real filter and never saw it again.

 

[Crazychick]

I was going to ask if it has a air filter fitted as I have seen similar problems on other cars when a airfilter isn't correctly fitted.

The throttle body should be easy enough to take off and clean yourself though. I had a similar problem on my phase one and it was pretty much doing what you said. For me I cleaned throttle body and ICV ( which I know you dont have as I believe its all done via the throttle body) and touch wood its been fine since.