I've got a 20v AMK engine fitted into a mk2 golf. It's been in a running fine with no problems for the past month or so.
Last night I was having a spirited drive on the way back home when the car started to sputter/heavily misfire when under boost/load, when building early stages to about 0.5 bar it'll happen. If say already at 3k in 3rd no load, if you were to put your foot down engine sputters, holds back. You can drive the car 'normally' with no load any quick build of boost, you probably wouldn't realise there is any fault with the car. Doesn't seem to be speed dependent either, just when the engines loaded.
At standstill, revving the engine - no problems.
I have VCDS - I've had certain faults codes always in there since the conversion, they are second lambda heating/no signal fault. CAN bus faults from other controllers not connected & intermittently a EGT impausible signal fault (keep in mind, this fault has been here the whole time the car was running fine) & N80 charcoal canister purge valve that isn't connected in.
Other than that, there are no new fault codes relating to the most recent problem.
I've been out done some logs, watched the data. Nothing occurs on the misfire counters, after a quick look I cannot see anything in particular to be flagging up out of the ordinary. I've disconnect the air mass, n249 & n75 valve at different times & no difference has been made to the fault. One thing I did notice is when I disconnect the n249 valve, the ecu thinks that the n75 valve is disconnect & vice versa - though this is possibly my fault from the conversion mixing up the wiring even when the plugs were swapped over the fault remained the same. I've taken note of the wire colours & pins & will check them tomorrow at both ends anyhow.
I realise after a bit of digging around for similar sounding faults from other members the EGT sensor could be at fault, though temperature reads fine & doesn't ever seem to be implausible when being logged, the fault (EGT fault code) only seems to pop up after the cars up to temperature. Brake light switch is also new (1 month old -after reading it could be at fault). The coilpacks are also 4 + years old so tempted to start there. Turbo was new/recon when fitted after a months use along with the actuator.
I'm struggling to find a way to upload logs without taking a screenshot of a bit of it, is there a way to upload the whole log? So far logs taken are: 001/031/112 & 002/115/043
Any thoughts/input welcome.