I wonder if anyone can help on a Misfiring issue

My 02 octy rs got mapped and i felt it was hesitant on ocations afterwards but i

left it for a week as it wasn't really intruding in the enjoyment and it was going back in to get Forge TIP fitted and 4bar fuel reg fitted to compliment the exhaust and filter already fitted and get fueling right for mapp.

the first days were great then it really started to hesitate which i then realised

it was misfiring and it was alot.

anything more than 1/4 throttle passing 2.5-3k revs and bang, it just didn.t like it.

So i thought the plugs may need changed so ngk PFR6Q were fitted, drove it and it was fine,

Next morning bang, it was back again, it just didn't like throttle at all

It freely revs from idle (not moving) but as soon as you drive and push down on the throttle (most noticable 2nd gear and upwards) it just splutters away,

Checked and replaced plugs again just incase they were faulty but no still did it,

No lights coming on and no fault codes are present (checked at 2 diff garages)

Disconnected Maf, the engine spluttered then settled, car still drove with mis,

Maf is 1 year old as replaced already, coil packs were changed at skoda for modified ones as car drove badly and the LIGHT came ON over a year ago.

Mapp was brought back to as near std as it could be with mods and the car drove

near normal (i could put my foot down) but very slight mis was still there somtimes but not all the time.

I checked to see if anything was loose but couln't see anything.

It def is worse when driving from cold, but when mapp activated its vurtually all the time

Has anyone got an idea as i am getting anoyed, tuner thinks it ignition related

even though no codes are present,

Please if anything comes to mind Reply

Vacuum hose? Mine had a similar issue when the hose under the small front engine cover (the one with hundreds of small holes in it) had split. If you can get it to idle badly with the bonne tup have a pull /push on allt he hoses and se eif you can get the engine to idle better by moving them.

Ill try that if whether permits sat afternoon

Thanks

For me, it was the rubber hose that runs from the red arrow (in the picture) round the front of the engine.

http://www.philgooch.com/octavia/hose1.jpg

http://www.philgooch.com/octavia/hose2.jpg

Its absolutly lashing down so i will check these hoses in the dry again just incase

thank for the pictures it makes it so much clearer

if it changes with temperature maybe its a temperature sensor in the system giving bad reults so causing the car to over fuel or retard the ignition maybe

Wouldn,t the sensor make a fault code appear

probably, i was getting the engine light on when cold and it was my coolant temp sensor faulty but it didn't affect running.

other have had different results though i think.

I have checked the hose and it seems fine

Next

I got alone of a single coil pack and it seemed to work so i got one, still slight hesitation on occation so will see if any other packs are on the way out before looking at other things again BUT

still baffled that no codes or light have been on or logged though

at least i can drive it

Cheers for the help guys

God damn this bloody car

Its back again,

Put a second pack on another cylinder to see if i could see if the slight hesitation would go,

No it got worse,

and for the first time ever the warning light came on,

local garage booked up till mid week next so cant get on diag, so iam ordering another 2 packs and see if the remaining old packs are now to week to function along side the replaced ones.

Do you think this is maybe the case? that the old ones cant keep up with new packs

Your views are more than welcome ppppplease

MY LUCK IS NO LUCK

Just got it back from getting check, the new coil pack is faulty also so

replaced it, and re-set plug gap down from recommended 0.8 to 0.6 and it seems to have worked.

I still feel there is the everso slight hesitation on medium throttle when accelerating somtimes but it cant be pinned to anything so i guess i will drive it for a while till i recoup after the garage bill, and get it on the rollers and

see if shows up at all

Thank for the help and info before guys

hopefully thats it sorted mate