rb20det missfire on full boost

[20DET]

ok...i have a rb20det which is a new engine i just put it...the old 1 blew....

i am running

front facing plenumfront mount intercoolerstandard turbowastegate3 inch exhaustwalbro 255lph fuel pump

and my car was running mint as yesterday...did a big phat skid....now it runs like s***

it misfires hard as on full boost...but only on full boost...have just checked the plugs...allgood...just replaced a coil as the bottom was broken off were it contacts the plug and had huge heat marks on the side the coil...

still misfires

thort it would be because it had no gas in it

still misfires with gas in it

ne ideas

it has a regulator on the wastegate and it usually runs 12psi...but now it only goes to 10psi and misses hard

[dtowngoalie]

Well since you're not seeing 12 psi anymore. It makes me think you possibly tore an intercooler coupler which would make it miss alot because thats a huge boost leak. I'd check your piping for boost leaks.

[20DET]

its got blow through maf....so it wouldnt matter if i had a leaking intercooler.......is this spark related anyone?spark plugs apear to be fine but is this a cause of a broken down spark plug

[NismoJunky]

mine was missfiring under boost, it turned out to be the coils. I coated them in silicone, and it stopped.

it sounds like you have a boost leak. a boost leak will cause it to run rich. your maf will read more air than what is going into your enigne.

[20DET]

ok heres a question for yas...done a diagnostics test on it...and it brings up knock sensor code??? it idles mint and runs fine but gets detonation on full boost....i think i mentioned before that i done a skid and it started detonating after the skid but no during it....could one of the knockies have goten too hot from the skid and cracked???

is it comon to break the knockies in these?? ive done a bit of research but not much has come up about it...wen i put my new engine in i put 1 knock outa ma old engine and 1 that came in it.......ive got a rb25 engine at home ill try the knock sensors outa that

[20DET]

ooooh...apon inspection i find the front knock sensor plug came off!!!!!!!!!!!

[20DET]

replaced both knock sensors and checked the knock loom for continuity...all ok...... reset the ecu and away laughing...no fault codes runs mint....funny thing is my car has the speed sensor wire cut going to the gbox and the the aic isnt hooked up and it still throws no codes haha...

just future references so people know if it happens to them