engine revs fluctuating between 1000 and 3000

[danbarnes]

hi i am having issues with my mk4 golf 1.4 it seems to have a mind of its own. when it is idleing the revs are around 900-1000 but soon as you touch the accelerator it begins to come alive and start reving up and down almost seems like not enough petrol is getting to the engine or something. the person who had it before me said that he had put on a different throtle body off a vw lupo could this also be the issue any help would be great thanks

[FLAPPERJACK76]

Yes. ..that's most likely what is wrong. You want the correct one. Clear any fault code's. . Erase learnt values Then a throttle body adaption carried out.

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[Crasher]

Each throttle body is specifically designed and matched to the ECU software, you can't just chop and change. Which year and engine code is your car?

[danbarnes]

My car is a 1999 engine code ahw what would i need to do once i have new throtle body please as going to try order one tomo thanks

[Crasher]

Not a very common unit as it is a cable operated unit where most Golf 4's are drive by wire so they are all old and worn out now. New, there are aftermarket pattern versions and aftermarket OE, the former nearly always cause trouble as do reconditioned units and second hand is a cockup waiting to happen. The VAG number is 030 133 064 F and they are £528.70, inc VAT... They were used in the Golf /Bora with the AHW and AKQ engine from 98>2000 ish and in the Lupo and Polo 1.0 with the ALL and AER engine 99>2000 Polo 6N1 APQ, ANX, ALL, AEE, AEX, AHS, AKR and AKV from 98>2000, Polo 6V saloon AKV, AEE, APQ, ANX and ALM from 99 >2002, Octavia 1U AEE 1997>2011, Arosa 6H ALL, APQ, AER, AKX and AKV from 98>2002 and Cordoba, Ibiza, Leon , Toldeo.....sorry, got bored...

Anyway up like, if I was repairing it I would insist on an OE unit (genuine is silly money) so a Pierburg 7.03703.36.0 or VDO 408-237-130-004Z and it is not unknown for these to be sold in other people boxes such as Vemo and Meat & Doria, but always check in the box before buying and if they ask for the old unit, walk away.

Euro Car Parts are showing they keep 2 types, one of which they only have 1 in the company and it is £3 cheaper than this Vemo boxed unit Vemo Throttle Body and if I was happy with what I found inside the box, it is what I would use as I have a feeling it is a Pierburg inside the box.

If you have a scout around ont tinterweb there are a few VDO and Pierburg ones listed (or so they claim) but be VERY wary.

Once the new TB is fitted it MUST be set up, this is quite simple. Firstly the throttle cable must not be too tight, only set on the adjuster steps so that it just makes full throttle with the pedal pressed fully down and sometimes the cable is worn which makes them tight and stops the quadrant fully returning which will ruin the set up, so I often set them up with the cable detached. When this is satisfactory, the TB has to be aligned to the ECU using a diagnostic system in "Basic Settings 04 Zone 098" with the ignition on, not running and with a fully charged battery and all consumers turned off. When the screen display says "ADP OK", exit Basic settings and turn the ignition off for 30 seconds, then back on, wait 30 seconds and then start.

[danbarnes]

Wow alot to take in there thanks was wondering what if i was to come across a genuine one in a scrap yard how would i determine if it was ok or not?
If it would work or not?
Would i still have to run it through the ecu aswell?
Sorry to ask so many question its the first time i have come across this problem thanks for helping

[Crasher]

You would have to take it and hope, it depends on how much time you have to waste. I won't fit used TB's or anything else for that matter, I have lost too much time with them and other used parts over the years. Even new parts are no guarantee that they will work, not even genuine!