has anybody got/used one of these?

the GF's mk3 nz is running a little lumpy and i really want to check the error codes.

This will be easy than going to VW right?

link

I know it only does engine codes but thats all I'm interested in...

Edited 28 August, 200719 yr by goatboy

Link doesn't work and the item number gives no results when you search for it.

I assume it's a VAG-COM lead? What end does it have on it? If it's the ODBII connector then this is no good for a mk3 polo. You also need the 2x2 adaptor to fit the double two pin connectors under the passenger side of your dash. Firstly make sure your car actually has them as I've heard of some not doing.

Secondly, digifant and digijet (which is what you have) are very primitive in terms of fault codes and diagnostics. The ECU will only show a faulyt code if a sensor is outside of it's possible range of values. E.G. the temp sensor could be telling the ECU that the engine is at 10deg when it's actually at +80deg. The ECU wont flag a fault because 10 is still possible but the engine will be overfuelling and run like crap. On the plus side, it doesn't store faults so there's no need to plug a tool in to "reset" fault codes once you've fixed the problem. Replacing the offending sensor(s) will cause the fault code to go away.

Your best tool is a £5 multimeter and a wiring diagram from a haynes manual. There is a thread in the Engine FAQ section on fault diagnosis. It's written about g40s but the same applies to your NZ engine.

I think you'd be wasting money and time buying VAG-COM leads as they wont tell you much on a mk3 polo.

If it's just running lumpy it might need new plugs & leads or the ignition timing might be out?

sorry, fixed the link now...

link http://cgi.ebay.co.uk/ws/eBayISAPI.dll?Vie...ADME:B:EF:UK:11

its a handheld scanning tool, comes with the 2x2 leads.

its running a bit rich, reading haynes tells me you can adjust the mixture but it won't do any good without wiping error codes.

Is Mr. Haynes telling me porkies?

by the way its got fresh plugs, leads, dizzy cap, rotor arm, blue temp sender, battery and all earth points cleaned and firmly fixed. Also cleaned all contacts for all the sensors and electrical stuff I can find so it shouldn't be a dodgy connection either...

Only thing I've not done is play with the lamba sensor but got a receipt for that being changed a couple of years ago...

Edited 28 August, 200719 yr by goatboy

does it run lumpy when hot or cold? or both?

it runs a little lumpy after it has been running for about 5 minutes onwards, so hot I guess...

Try changing the blue temperature sender, this sends temp data to the ECU and is a common problem.

already done that one! :-D definately helped but still not perfect...

Fair enough! Am I right in thinking your engine doesn't have an air flow meter? (only really familiar with GT layout) If so, the next most likely suspect in my opinion would be the lambda.

hmmm good question. I think it does doesn't it? It certainly has some sort of sensor on the airbox...

yes it'll have a air flow meter on the air box.

I guess to maybe narrow things down once its warm its revs will sometimes randomly drop a little when idling. Imagine what its like when your engine gets up to temp and the automatic choke cuts out and the revs drop. its like that. sometimes it doesn't do it, sometimes it does. does that help narrow it down?

Also whilst were are on it what is the second butterfly in the throttle body for?

This thread should probably be in the engine section now :-D

Thanks for your help

Possibly blue temp sensor gone. Have a read of the guide hayesey suggested.

the second butterfly opens at around half throttle