Hi,

I've got a problem with my throttle body (I've got lots of problems with this car, but lets try this one first)!

My car idles very slightly rough. It's juddering at about +/- 20 revs constantly - feels like the car is on the verg of stalling.

I've cleaned the throttle body, and I've had it recalibrated and I've had it VAG COM'd, there's no faults.

The guy who did the recalibration said it might be a broken wire in the loom and I should test this first (he thinks it's a new throttle body job, but said to start with the loom) I've got a multi meter and no idea how to use it!!! LOL

Is there any info on here on using a multimeter? I've searched but can't find anything :(

and

Is there any documentation on here about the 1.4 16v AFK engine ? again, I've searched but can't find anything :(

If I'm going to check for a small break on a piece of wire, I might als well check everything else while I'm at it

Any help would be most appreciated : )

Peace x

This engine as standard or modified? You can check using this > http://www.vagcat.com/epc/ may have to go back to the forum page to register and log in but itll have all in the info youll need to find out what to buy.

This is the wiring connections for the throttle body, the wire maked RO/WS 24 (pin 4) goes to pin 64 on the ECU

Put the multimeter selector on the diode symbol and touch the red & black wires together it should sound a buzzer and the display 0.00?

If that works, remove the connectors from the ECU & throttle body, then put either the red or black wire from the meter into the removed connector from the throttle body pin 1 and the other lead from the meter into pin 66 of the ECU plug if the buzzer sounds the wire is continous and OK then do the same for the rest of the pins on the throttle body connector

Thanks for getting back to me.

@ Nige - My multimeter is from B&Q (http://www.popultek.com/en/products/20121004/m300-digital-multimeter-pocket-size-one-hand-rotary23.html%C2'> a bargin at less than a tenner!! LOL) when yo say 'diode symbol' do you mean the ohm (like a pair of headphones with feet?) I've then turn my dial to the speaker looking icon (last one at the top of the series) and yes, there is a squeaky, high pitched, staticy noise ? :)

@ Dooley - I'll have a look at that and register now :)

If there is a position on your meter marked 'CONT' or 'CONTINUITY TEST' that will be OK.

Had a look on the B&Q site could'nt find one for under £30!! but if it has this symbol Ω select it to the lowest range and then your looking for as close to Zero on the display this indicates a good connection, but if you have a selection that makes a noise when the probes are touched together use that as it makes it easier and again when you go between the different pins you want the buzzer/squeak to sound for a good connection

@ Nige - yea, I had a look too and it's not there :( But yes, that's the symbol :) As to the range, it's reading all over the place from -001 to 600!!

So do I :

Disconnect the positive leed from the battery

Disconnect the Throttle body cable & the opposite end on the ECU

Touch pin 66 on the ecu end of the wire (and not change that position) and then starting at pin 1 (on the throttle body) test all of the pins one at a time at the throttle body end?

All should make a noise if they're OK?

If I find a broken wire, is it possible (and easy to fit) a new leed? or do I need a new loom?

With the wires from the meter touching eachother the reading should be Zero or making the buzzing/squeak sounds once this is OK, disconnect the battery and then the plugs on the throttle body & ECU then put one lead of the meter (does'nt matter which one) into the throttle body wiring connector PIN 1 and the other lead from the meter into the ECU wiring connector PIN 66 if it's a good wire the buzzer will sound or it will read ZERO, then try PIN 2 on TB to PIN 59 ECU and so on in that diagram, as to repair it's probably easier to get a replacement loom as breaks in the wires could be anywhere

OK - I've gone through the wiring

first off, I disconnected the negative leed on the battery and removed the air box and ECU cover (thing).

I couldn't see any numbers so I just pressed my multimeter lead to one point on the terminals on the throttle body wire and then tried ALL the connections on the (smaller) of the 2 connectors of the ECU

Every one made a noise : )

So - I take it this means the look is OK ?

if so

Then do I take it that my throttle body needs replacing / repairing?

Any ideaas on where to get a throttle body?

and will I need VAG COM to install the replacement / repaired throttle body?

Peace x

If they all made a "noise" then that means the wires are OK with no breaks, so next is to try another throttle body, so I'd put a "Wanted" ad in the classified here's the part number

036133064E

throttle valve control unit / F 6N-W-105 001>>*6N-X-240 000*
/ AFK AFH

As it's common to the one fitted on the 6N 1.4 16v AFH engine there is a good chance of someone on here having one sitting around due to the popularity of converting the AFH to run on bike carbs.

Although I have the full VCDS/Vagcom I've never found it required the " re-alignment" proceedure, it's a bit lumpy for a while but after you've driven it for 10 mins it re-learns the values and then runs OK

cool - I'm really lucky, the guy next door to me just told me he has VAG COM LOL - wish I'd known that a couple of months back :/

I found a NEW one online earlier -£75 but they 'had to see if they had one on the shelf' suddenly it's £200!!!

BBA Reman (http://www.bba-reman.com/UK/) can do mine for £150 with a lifetime guarantee, so not sure whether to get a new one or second hand - I'll have a look and post an ad

Thanks for your help :)

HI,

I got a used (but working) throttle body, changed it over and .................................... the problem is still there!!!

I think it's very unlikely that the second throttle body would have the same fault so what else can I check??

The car starts fine, but after a few minutes it starts hunting - it's not a massive ammount in the rev range (+/-20 rpm) but it's enough to :

Sound odd

make the car, judder vibrate

It's just not right - any other ideas?