Help needed

[lemski]

Might not maie a difference as the ecu corrects fueling. Ive not come across a car running bad because of bigger valves.
I have however got a customers agu in that is bogging down misfiring below 3k. I unplugged and cleaned the throttlee position sensor and plugged it back in and seems to have resolved it. Ill know for sure when I take it out In the morning

[Sammy14913]

Already cleaned the throttle body and reset it and it's the same all I get off everybody is remap the car and it will solve it might get new coil harnes as apparently they get funny over time due to engine heat... But everything has been done I got no codes no boost/vac leaks compression has been checked and its 165 all across. I read on here somewhere that the spark plugs have to be gapped to .028 as this can make a 1.8t misfire due to density of the air... other then that there isn't anything else apart from it running rich

[Sammy14913]

Just realised what you meant mine is electrical throttle where is the sensor located and how do I clean it I'll give that a try

[lemski]

Its under the throttle body, I cleaned the connection on this one, was a bit of dirt in the contacts.
Spark plug gap should be 0.6mm
I got some plugs the other day that were 2mm gap and had to be changed.

I dont know if a map would solve it. It could make the problem worse because of the extra load on the engine.
Have you checked the lambda?

[Sammy14913]

Yer bank 1 position 2 was out we changed it reset and hasn't come back on again where as before it was being cleared and coming straight back on when you started the ignition the only code on there is secondary air sensor open circuit but that's been removed and blanked and have been told that wouldn't cause the problem.

[Sammy14913]

Thanks for your help people.. Come to the conclusion I'm Gona get rid of this thing as the problem can't be resolved

[Sammy14913]

Had the car on the ramp at work today and it has a leak from the flexi down pipe would this cause the misfire /flat spot up until 3k and it running rich? As the problem seems to be getting worse

[lemski]

2nd lambda would read wrong. I assume 1St lambda is befire the blow.
So it would put more fuel in and possibly over fuel it to the point of spluttering

[Sammy14913]

1st is before the cat after the flexi and 2nd is after cat so the leak is before the 1st ... The mechanic at work has no idea as we have done everything possible he has a mk5 gti took it to a vw specialist and I told them what we have done there reply was have not got a clue take it to a place that deals with modded cars all because it has a agu head some specialist they are but now it isn't just a miss fire/flat spot it's starting to judder when it's in the flat spot.

[lemski]

It would make it overfuel still being as a lamda is reading lean with the blow.
I cant see why it matters its modded. Engines still have the same problems.
Sort the blow mate and see if it gets the judder gone. It should help with fueling definately