Hi, After my aggro over the weekend with the ECU light on and the dead speedo etc etc I took the Mrs's Ford Mundano to work and left her my Vrs, She drove it and text me saying it was all working!!!!!! After i had ordered a new vehicle speed sensor as the fault code said it was that, However after my local garage has read the codes and reset the ECU the car has a horrendous misfire when cold, If its left to run until the idle dies down (approx a minute and a half) it seems fine, Also on the motorway it seems a little hesitant under acceleration, I wondered if anyone has had this problem?, Will it need a remap after being reset?, Cheers all.

Most of us wait till the revs drop before driving off for exactly that reason. It's when the secondary air pump is running and most will run like crap for that first minute or so.

Not the same sensor but I should imagine it works in the same way as your problem one. when my engine speed sensor packed up I could clear the code and it would be fine....for a day or 2. Then it would return and run like crap again if I could start it at all.

So it is worth changing if it's thrown a fault.

Ian

Agreed, secondary air pump casing is split. You should be able to see the split if you jack car up and look all round the pump. They sound like a spitfire when leaking.

So i take it that i need to replace this air pump? how much are they and are they easy to fit?

No just drill the rivets out and bolt, good as new.

So i take it that i need to replace this air pump? how much are they and are they easy to fit?

No no no. follow this link for a repair guide Step-by-step guide for repairing the Secondary Air Pump (with pictures) - uk-mkivs considerably cheaper than a new unit

Ian

When you say hesitant on the Mway what speed, gear and revs are you talking, are you sat on the edge of boosting or in 5th at 2000rpm and trying boot it????

Also on the motorway it seems a little hesitant under acceleration, I wondered if anyone has had this problem?

Does the turbo still sound the same during motorway cruising? I had similar, it was going into limp mode during sustained motorway cruising which only gives you 5 psi boost pressure. A MAF change cured it.

Ian

I dont know how the turbo should sound to be honest, In comparison to my Nissan skyline that i sold to buy the Octavia it sounds loud I.E. i can her the turbo whistle when i accelerate, It seems to do that in every gear, I would say 70-80 MPH in fifth gear and when i do accelerate it seems to pull back 1st for a second before accelerating. It also does this say in traffic in 2nd gear as well, Our unmarked ones at work both feel different to mine to drive in the fact they seem more responsive even with a heavy load of equipment on board, The turbo's on these ones we have also whistle fairly loudly under acceleration, For your info the reason i bought my Octavia VRS was due to the fact our work ones get such a hammering and still go on and on and on, One of them is 3 years old with 165,000 on the clock and is very reliable so it seemed a good choice to make.

Try a throttle body clean for the hesitation, whistle is quite normal. Is your car Remapped?

No but it has had a recent fault code read and then a reset so i was wondering if that would be it, I run it on 99 RON fuel as well.

The ones at work may well be remapped. Clearing the codes should not require an ecu learning process but these cars can get a little sleepy if they aren't driven hard all the time.

Funnily enough today i didnt get the misfire but got kangaroo'ing instead:rolleyes:

Funnily enough today i didnt get the misfire but got kangaroo'ing instead:rolleyes:

have a look at this thred http://forums.vwvortex.com/zerothread?id=1269869 it may help,read it to the end i think somebody explains what yours is doing