Hesitation under boost

[BraneDeadx]

Ok im stuck hear in a bad one, hopefully i can figure it out on my own but ive tried mostly everything i can think of with no secuess

of course back ground is a 4 banger 1.8 littler 8:1 CR stock head work bla bla bla turbocharged etc.... running MS2.33 EDIS4 what not...

it seems after makeing sure my VR pickup sensor was sound and brand spanking new, plugs are new etc.... motor is sound (i hope).... i recently swaped in higher boost springs in my wastegate, in my datalogs im seeing 16~18ish boost which is around where i want it for now any how....


on ignition side ive sloped the table so ofcourse in higher boost rangeim seeing 20~18 and 16 degrees at anything higher 20 psi!

another step i took was to adjust my fuel presure so im adding in around 6 psi of more presure nearly 46 psi under boost which before was 40 ish.... this help me lower my duty cycle at full boost before i was seeing over 80% with 42lb injectors ??? dosent add up....

so this is problem, anything after 4000 rpm my engine just runs out of power, it makes a wierd sorta hissing sound and bucks a bit, i never felt a real "knock" from what ive heard its very viloent like "hitting a hammer on top of piston" , i doubt thats whats happening on wideband side of things im in very low 11's AFR its hard to see cleary if its really leaning out but im sure if it was that bad id see it ?....

so with me dumping more fuel in didnt help things much, maybe my wide band is lieing , i doubt it, the inovtative software is perfectly mattched to megatune, i did a free air calibration but no different results...

last, i did a presure test on entire system, i thought maybe my vacume line to megasquirt was blowing air out of it, i hit 20 psi with everhything attached and did not notice any leaks what so ever (with engine fully warmed up) something that came to mind , when this hesitation happens it feels like someone is redline a motor and the valaves cant open and close no more (floating) thats about cose as i can get to describeing the feeling.... this is on a "new" head with all new parts on it...

very wierd situwation, my last dead hope idea is to get a scope on the injectors and hook up a simulator to the EDIS module to fake out the vr sensor and rev it up to 6 grand see what the injectors look like.....

help


in log look at 1249 , thats basicly what im seeing engine just stop reving past that point....
Sean....

http://www.motorsportwerke.com/e30turbo/datalog1.xls

ill attach my log to this post... im just stuck dead right now clueless to whats problem

[schmidt]

Just an idea...

Aren't you using too much gap on your spark plugs ?

Cheers

[BraneDeadx]

to tell u the truth i really dont know, these plugs came out of a subrua wrx sence i figured they are colder plugs and there NGK;s rated at 6 whatever temp range they use....


basicly i did a few runs today and had the nerve to pull my entire ingtion table back 10 degrees (advance) and that made the most biggest impact yet.... over all i guess my VR sensor isnt alinged properly.... despite what the megasquirt manual says about placeing it 9 teeth away from the missing tooth, i made sure it was correct but im pulling 27 degrees advance at 19 psi of boost.... that seems ruffly a lot for that much presure... i need add a timing reference mark on my pully to double check if my base timing is correct


overall the car is awesome! what a big impact this made.... i was shakeing after i came home driveing it , car is way to fast for me.... hehe

wow...

[mops]

yeah, sounds very like you are getting spark issues at high boost.

it's either missing or weak or getting blown.

try reducing the spark plug gap, then again, subarus run normally 0.7mm, so there's not much to reduce the gap from....

make sure no ignition lears are arcing - sometimes they arc through body/engine parts - make sure these are to specs.

make sure all your coils get all the power they can get - ground them good and power line should be phat! - if they are getting slight less than they should you will get what you are describing...