1999 Octavia 1.6 GLXi Tick Over/Hunting Problems - Anyone Help?

I've only had the car 2 months (Oct 1st 2007)

Hi I've got the 1.6 AEH/AKL Multipoint? fuel injection engine.

Some days when you start up, it runs fine. Other days, the tick over wants to die/drop off, if you have the lights switched on as the rev counter goes up and down (between 400 - 1500 rpm) the lights go dim and then back up bright. This slow hunting occurs night or day, making pulling away a delicate process. Causing stalling if not to awake in the mornings. It's very worrying to watch as it slowly drops off to stall, only to climb back up, then drop back down again, repeating the process until you try to pull away without stalling.

I first noticed the problem when lifting off the pedal/throttle while driving in normal traffic, the revs would drop off alarmingly, as though there is no throttle stop. When changing gear only being caught by releasing the clutch pedal.

I used to have a 1994 Seat Cordoba with the 1.8 Passat single point fuel injection engine, and that setup was great, never any problems with starting/tick over etc. (Car just started to rot too much to repair) Amazing as you started the car, the pedal would move away from your foot as the system gave it choke or changed the settings for starting.

This problem with the Octavia is driving me nuts, I went to move my car on the drive the other night and I just could not get it to tick over steady, without stalling, I must have restarted about 5/6 times trying to move it.

I was going to check it over this weekend but the weather forecast isn't great, too old to enjoy getting wet.

Any suggestions?

Anyone suffered the same/similar problem?

Hope someone can help (before I take a stick to it), Cheers, Pete.

PS. is it worth getting a code reader and which ones would you recommend. Are they easy to use for the complete novice?

Don,t know if this might help you.

I used to have a long time ago a Cavalier SRi 130 Mk2 that used to do the same thing.

The cause of the problem was a dirty throttle body(inside) after cleaning out with normal Carb cleaner sprayed inside and new air filter and a good dose of Injector cleaner in the tank the problem disappeared and never came back.

Maybe worth checking these? as a help.

Well I've tried the cleaning process, twice. All I've got now is a car that either REVS at 2000 rpm or keeps revving from just over 1000 to 1500 rpm constantly in quick bursts. I've tried the SOFT and HARD resets as suggested in another Octy 1 thread. Still won't settle. Great fun at the lights or a junction, you look a complete T**T.:eek:

When you start first thing in a morning, the revs seem fine, drive down to the end of the road, up they go again. It seems fine to drive at speed, just frustrating listening to the engine do this when de-clutched/out of gear.

As 'James in Norway' commented, when you disconnect the grey plug (8/6 wires? not sure how many) from underneath the throttle body, the car settles to a fairly standard tick over.

I am at a loss on how to cure this, without going to a garage. I don't have much faith in them after reading the threads on here. I don't have access to a code reader, so I'm stuck there.:(

Can the cleaning process have affected the electric/tronic controller on the side of the throttle body by seeping down the shaft? Has anybody taken the black plate off? to have a look whats inside. Is it worth taking it off to check it out (Hope it's not full of springs, I hate springs, especially when you don't know they're there)

Can you test the Air Flow Meter? the part that sits just past the air filter box. It has a wire across 2 bars at the open end (engine side) and if you look through the mesh end (filter side) there is a similar set-up. The plug has four wire connectors, any checks for this.

I am stumped with this one.

HELP:(, HELP:(, HELP:(, think I'm giving up the will to live.

I seem to remember there being an oil breather hose at the top of the engine that causes your symptoms when it splits due to the air leak it creates on the induction system. Do you get any strange smells? Your fault does sound very much like an air leak, do you get a hissing noise while the engine idles? Also check the air intake hose after the air flow meter for splits.

Well, I seem to have checked everything.

IT SEEMS TO BE WORSE THAN EVER.

Pull up to a stop and the revs climb to 1750 and stay there for what seems an eternity, then maybe drop back, then back up and down.

I can't find any air leaks, even using the spray method.

Spoke to a local VW specialist garage who have a code reader, they've asked me to take it in Saturday, so they can connect it and check the codes, clear them and see what reappears.

Their comment was, 'it does sound like the air flow meter', after all the checks I'd described to them.

Spoke to Skoda parts as well to check up on the part.

Over £250

or £90 ish exchange

for an AKL 1.6 Petrol Engine

(I think thats what they said, I was still in a state of shock. Stood there, phone in hand, holding this small piece of kit - Part No. 06A 906 461B, AFH60 - 10 C, Dated 2 27/99 HITACHI) There's too many swear words in what I was thinking to put on here.

I took my daughter to the Bristol Children's Hospital this morning in HEAVY stop start traffic, I just can't live with the car like this. (oh and it's showing 23 MPG overall, what joy) I just want to burn the bl**dy thing.

I will let you know the garage report and the progress we make, unless I TORCH IT, before then.

WORD OF WARNING:

DO NOT CLEAN YOUR

AIR FLOW METER

OR

THROTTLE BODY

I could live with the original symptoms, but these I can't.

Did you get to the bottom of the problem? Mine is V reg 1.6gxli also and has just started doing exactly the same

Easy way to check the MAF sensor is to disconnect it. There's a recent expn of why by me somewhere about.

I had (and still have to an extent) this problem on my 1.6GLXi. Could be ok then at times revs would bounce. On a couple of occasions the car lost all power for a split second when in town at 30mph before revs increased again.

There was a split in the hose which goes from the oil filler cap to the main air duct, replaced this, approx £30, no difference. Cleaned the throttle body which was clean and this made no difference. The MAF also got cleaned and again this made no difference.

I checked and cleaned the connections to all engine sensors to eiliminate these too, including the coolant sensors as I have heard these can give poor feedback (my temp gauges were showing ok).

Got the fault codes read and a fault was recorded against the lambda sensor (intermittent open loop/readings outside expected values). Got this changed and this has sorted the problem by about 85%. The revs aren't boucing like they were but they aren't 100% steady.

If you watch the rev needle and listen to the motor you can hear and tell it isn't idling perfectly. I have put this down to the throttle body. I beleive there are flatspots on the throttle body potentiometer due to age/use and this gives bad readings back to the ECU. I would like to dismantle the throttle body and clean the track but i do not know what it will be like when i take it to part i.e. can I get it together again!

Would be interested to hear from someone who has allready done this.