UK-POLOS.NET - THE VW Polo Forum

hey guys, sorry I haven't been on in a while,
work is a real pain at the moment.

just got a bit of a problem with the acceleration, when I put me foot down she shudders and amost stops, then goes racing off.

I'm sure I saw this before on here, but i can find it..

any help?

I'm not too hot on this, but have you checked the throttle cable? No slack in there is there?

Just a thought. Sorry I couldn't be of more help!

Karl.

Hmm Well the only time this happened to me I traced the source to a dodgy HT lead. Have you checked the ignition timing?

I've just fixed exactly the same problem on mine, it was just running far, far too rich (like, flooding the cylinders with fuel every time I put my foot down, no wonder it was only putting out 33mpg..). Check your spark plugs, if they have a black coating on them, weaken your mixture (I assume this is adjustable on the mk3 throttle bodies and doesn't need electro-trickery with the ECU?) and it should improve no end...

I dont think you can adjust that on a mk3 that sort of thing is governed by the lambda probe and ecu.

I G N I T I O N L E A D S

you knows it homeboy

er, well, at least, i THINK thats what was making mine bellyache in a similar manner before

if you have a tacho, is it kind of like there is bugger all below about 2500rpm, but after that its fairly normal? (i had that *really* wierd symptom - still dont know quite what it has to do with the leads, but changing them fixed it!)

Shame, would have thought in a basic injection system they'd allow for a certain amount of manual adjustment... In that case I'd suggest checking the lambda probe etc, certainly check the plugs to see if it's overfuelling. My symptoms from having a very rich fuel mixture were poor economy and major flat spots (almost complete dead areas) around 1-2000 rpm, particularly noticable when I pulled away in 1st and 2nd gear where it would almost stall until either I floored it or it got over about 2,000 rpm. Spark plugs were absolutely covered in carbon, which has cleared up and been replaced with a grey-brown sort of colour now I've sorted it out a bit.

You can adjust the idle and CO content on a GT but thats about it. The single point injection engines arent adjustable at all as far as i know.

Surely CO content is effectively just the mixture anyway?

Aye, you are right Gaz. I have the booklet here on the Bosch Mono-Motronic SPI injection system, which is used on the MK3, and it is all self-regulating. Nothing can be adjusted, not even the idle point.

My spark plugs are carbon fouled, but there is nothing that I can adjust. It may be because I do a lot of short journeys, to and from work.

i reckon you could do some kind of adjusty by whacking a rheostat on the temp sensor...

dicking about with that has made mine idle down to 500 revs before and seems to richen the mix