Rough running...

[mustard]

I have a Polo 1.0 ('95 mk3 model) exciting I know! (do have other cars!)which every time about a quarter of the way through warm up cycle starts to run rough and lack power for a short while, then will run absolutly fine, other than this it runs great.

I have replaced HT leads and plugs are nearly new, any one got any ideas?

[iains]

This could be a large number of things......

I don't know the 1.0 particularly well, but from my general knowledge of VW engines, and the vehicles age, it could be one of these. Firslty, check all the obvious ones like fuel filters, timing etc.

Firstly, the air intake is governed by a vacum driven switch which works a flap that takes in cold air from the front or 'warm' air which is heated by sucking it in from over the manifolds, or a mix of the two. These units are prone to fail and you end up freezing out the carb / air intake system. It costs very little to replace. It will be located at the point that one of the vacum tubes joins the air intake / filter line from the front of the car. Test by removing the tube to see if the flap moves.

Also, if this model has vacum advance (dunno) then the vacum line or the sack inside the dizzy could be done for.

Alternatively, if this is a carb model, or even if not, there is a temperature control / sender unit which is a bi-metalic strip that is in the coolant line. This governs the automatic choke / warm-up process. Over time these strips break down and the result is that the choke comes on and off - you may notice and increase in fuel consumption if this is the case.

That's all I can think of the minute - let me know how you get on.

Iain

[mustard]

thanks for those pointers.. I'll have a play, must be somethin stupid because it runs fine except for about five mins when its about a quarter warm (which is normally just as you hit a fast moving island and you need all the power you can muster with a 1.0 Polo!)

[mustard]

would the vacumn switch be about an inch quarter diameter plastic component(with Bosch on it, Bosch description "canister purge valve)located on the left hand side of the engine bay with quarter inch rubber pipes at either end? if so i think thats the problem playing with it

Cheers

>> Edited by mustard on Monday 29th December 13:05

[iains]

might be - I'm not too familiar with the 1.0 lump - will link into the air intake in some way if that is the bit.

[cosmoschick]

mustard said:

I have a Polo 1.0 ('95 mk3 model) exciting I know!

How's the new company car

[mustard]

cosmoschick said:

mustard said: I have a Polo 1.0 ('95 mk3 model) exciting I know! How's the new company car

Oi cheeky! ..... this is just a little profit opportunity! The Saab 9-3 is fine thanks

I'm like you Roz.... need a little German to play with

>> Edited by mustard on Monday 12th January 18:48