Erratic Idling

[Eazo]

Hi everyone, I hope someone can help me before I have to take the car to the local stealer (or a hammer to the car!!!!). Apologies for the long thread.

I have a 2001 (Y) Mk1 Leon Cupra (1.8T 20V). About a year ago the yellow pollution warning light came on and stayed on. I didn't worry about it because it didn't seem to have a detrimental effect on the drive.

The light recently came back on again but this time was accompanied by erratic idling, sometimes to the point where the engine almost cut out. I had a mobile tuning guy come out and hook it up to the computer to read the fault codes. It was diagnosed with a faulty coolant temp. sensor and I had a new one fitted (the modified green version). This seemed to solve the problem and the fault code has not returned.

Within the last month the idling problem is back with a vengeance and the car feels worse than ever. It has been hooked up to the computer again and the following fault codes came up;

17545 Bank 1 mixture adaptation (system too rich).
17608 Recirculating valve for turbocharger - N249:mechanical malfunction.
17705 Connection charger to throttle valveressure dropped.

There do not appear to be any leaking hoses. The tuning guy suggested I change the lambda sensor but didnt seem convinced. After cleaning out the throttle housing the idling has improved but the car feels slow and not very responsive.

I have been through all similar threads but I am even more confused now, what with maf's, coil packs, etc.

Has anyone else encountered similar problems? Any comments gratefully received.

Many thanks

 

[m0rk]

if you drive for an extended period with a dead coolant sensor, your car runs on choke all the time. hence system too rich, and possibly dead sensor

also worth checking the MAF

both can have the effect of rough idel

 

[dazzlin75]

Having very similar problems myself at the 'mo.

Engine light on - feels sluggish, almost as if the turbo isn't spooling up properly (or at all).

Same motor as yours (2001 Y Cupra) and it's booked in to a local place this coming Wednesday to be sorted out.

I'm betting on dodgy MAF and maybe N75 valve.... so possibly goodbye to £200+...

Will let you know what happens...!

 

[Eazo]

Thankyou both for your replies.

Mork - when you say dead sensor do you mean the lambda?

Dazzlin - Sounds like it could be the same problem. I may have to bite the bullet and book it in somewhere because it seems like my tuning guy has gone as far he can with it. Look forward to hearing how you get on next week. Hope it doesn't cost too much!!!!

 

[dazzlin75]

Thanks - can already feel the pain in my wallet.....

I think the coolant sensor is a different beast to the lambda. Not exactly sure of the technicalities though. Sure someone on here can help...!

 

[Feel]

I think it might be as simple as an air/boost leak, probably on one of the smaller hoses on the vacuum side (i.e. after the throttle body).

Check between the n249 and the dv (search for n249 removal for pictures) and under the intake manifold. It'll be a bitch to find.

 

[Eazo]

I've driven it for a couple of days now and the idling problem seems to have gone. The warning light hasn't come on either. Cleaning the throttle housing out with some WD40 and a rag must have solved the problem.

Its still lacking in the power department though. I'm starting to think that I should change the lambda sensor and maf anyway. Does anyone know how easy it is to change the lambda sensor??? I put a new manifold and lambda sensor on my girlfriends Ibiza yesterday. Ther sensor was easy to get to and I was wondering if the Leon is the same?

 

[willy_ham]

Hello, i have had similar problems, but have now nearly resolved them all.
The first big problem was surging on cold starts, this eventually turned out to be split cable insulation going to one of the spark plug coil packs! Simply resolved with some good quality insulation tape.
Its is also worth while having a good hunt around for any other cable or connectors that look loose, damaged, corroded etc. Give them a good clean and push them back together firmly.
Check your dump valve is functioning correctly, mine failed a while ago (it was the original bosch rubbish), i now have a forge unit which was working fine till the other week, where i had all sorts of problems, and after a trip for diagnostics it turned out that the lid on the dump valve had come un-done!
Follow all your pipes that have anything to do with air, and check for splits, and ensure they are securely fitted, you may find one loose.
the n75 valve is located close to the dump valve on top of the engine, ensure that the connector on this is secure and clean, and that the pipes are all ok.

other than that, i havent a clue, but maybe it has helped a bit.
Regards

Will Lennard

 

[Eazo]

Thanks for that Will. I'll check as much as I can at the weekend. Taking it to the SEAT dealer is a last resort for me. I'm waiting to hear back from dazzlin75 (see above) as my problem sounds similar.

Cheers

 

[dazzlin75]

No probs - will let you know the score as soon as I have my motor back (hopefully Thursday...)

 

[dazzlin75]

Just had a call from the garage - they're 99.9% sure it's the MAF and are currently slapping a new one in.

£150 (less a few pence) fitted inc vat. Pretty much what I thought..... so let's see how the swine drives when I pick it up later on!

P.S. You know how SEAT dealerships have that deal where they can exchange your dead MAF for a refurbed one? Sounded good when I called them prior to booking in at the existing place - was about £80 for the MAF unit itself - until they told me it would be an extra £110 for fitting......!

Moral of the story? Stear clear of main dealers (unless you're still under warranty).

 

[Tallpaul]

P.S. You know how SEAT dealerships have that deal where they can exchange your dead MAF for a refurbed one? Sounded good when I called them prior to booking in at the existing place - was about £80 for the MAF unit itself - until they told me it would be an extra £110 for fitting......!

Why not just buy the part and fit it yourself? it's held on by 2 screws and a jubilee clip.

 

[Pabs]

yeh, kinda ditto tallpaul on that one - shouldnt be hard to do yourself.

 

[dazzlin75]

Ha! Didn't know that.....

Too late this time, but I'll remember for the next time.......!

(Note to self: must learn to tinker under the bonnet more rather than just whipping the damn thing in to a garage...)

 

[dazzlin75]

Just got the motor back - drives splendidly.

And it only cost £113 all in, not 150. Fitting was just a tenner (plus vat), so I don't feel too bad about not doing it myself now.

 

[Eazo]

Thanks for getting back to me. I think I'm going to have a new MAF fitted now. The idling problem has not returned since I cleaned out the throttle housing. I drove back from work earlier and had to stop off at a few places on the way back. The last time I tried to start it it didn't want to fire up until I gave it some gas.

Am I correct in thinking the MAF is the air flow meter?

Does anyone know how long it would take to fit a new one myself? Is it a fairly staightforward job for a novice like me?

 

[dazzlin75]

Yup - MAF = air flow thingy.

The guys in the above posts think that fitting it should be easy enough.

I'm a butter-fingered idiot though.

 

[bigmofokev]

mines the same

got all your probs bad idle the lot.
did 17608
checked and cleaned 17705
changed 02 lambda.
STILL DOIN IT.
Please someone tell me the maf is goin to fix my little coop shes drivin me mad.
Shes got to make me smile again soon.
one more thing
When comp gets plugged in and all faults cleared she runs sweet for a week maybe two.
my man says earthin ? maybe.
any ideas?

 

[STEVEO@CYMRU]

i have the same problem , had it before and it was the temp sensor so am going to try that again... 17705 if any body finds out about this code i will be well happy , i have had it for about 3 years and it always comes back .. i have tried many things and its still the same

 

[OrangeCupra]

ive had the same few problems on my 2001 20vt when 1st started in morning it surges at high revs then dies down after a few mins??aint a clue wot that is???
then it started to idle really bad so went to work and put the diagnostic on it and it came up with the following codes
07608
17705
17704 and im not too sure if i read the last 1 wrong or not but ive wrote down 16486???
so...so far ive changed my maf and its going ok so far apart from the surging in mornings or when left fot ages without starting.but im going to change my coolant temp sensor as ive been told 1 of those codes refures to that so...not too sure wot the other's are so if anyone can help??plz lol