Nistune Forums

So either its a coincidence or not but here goes.

Back story, recently just had a whole new setup with a top mounted holset. got a full tune using a z32 ecu.

got it back and was sorta happy. but the tuner didnt really know how the setup should be acting. so it was not boosting till 5000 rpm and the tuner thought that that was normal for it being a big turbo.
Well i knew it was wrong and they didnt believe me. so i took apart the setup and low and behold. found a piece of left over slag from welding somehow got jammed inside my external wastegate and kept it from closing.

removed it. put the cat back together and went for a drive. it now boosts at 3000rpm. I didnt go hard cause the tune wasnt set for it coming in that early but soon after a few min the car started to bog and cut in and out while cruising with the afr sitting at 10.5. it would go away if i gave it some throttle
but now at idle and light cruise it surges.

any idea?
currently not running stock o2. just wideband and the motor is just running of the tune.


Could there be something now wrong with the tune since it originally tuned around a big issue?
thanks!

-Will

Try doing an AFR trace using the software and see what the mixtures look like

If they dont look like 14.7:1 on cruise and around 11.5:1 on boost (as a general indication) then it may require retuning the maps

well i know already that it wont doing what its suppose to but i will go run another log and look at the trace.

when i try to cruise everything is fine until i try to retain a speed. then afrs go from 14.7 to 9.5 and the motor starts chocking until i either decel or give it a tiny amount of throttle where it becomes normal again.

Other thing to check is your Alpha N Increase fuel table. This is used on acceleration. Set all to 255 values so it doesnt use last column of fuel map on heavy throttle

After this recheck in the AFR tracer

Unsure otherwise without seeing tune, but it appears another retune is required if when going on load it is going massively rich