To start my setup is z6 block, y8 head, with z6 dizzy. 7 psi tuned on chrome. Just recently i dont know when it started exactly but between 4200 and 5500 my car cuts but the a:r's stay in the 11's. vtec engages at 4500 but it doesnt seem like it matters. sometimes it cuts at 4200 and sometimes cuts at 5000. but always stops cutting after 5500. Its like the spark is being blown out, but i got brand new ngk spark plugs(which were recomended by a shop) gapped tighter than normal. but the wierd thing is, if i do 3/4 throttle all the way through any of the gears it doesnt miss at all. but as soon as i do full throttle from 4200-5500 it stutters. and this problem doesnt happen every time i boost tho either. ANy ideas would be greatly appreciated and if u have questions because this doesnt make a lot of sense please ask.

 

help

 

I have been having a similar problem with mine cutting out right before redline. After much fun and research, I believe the problem was related to the fuel cut value being set too low in my Uberdata program. I have since raised the value and am retuning the map -so far so good.

 

im the one doing the tuning on this car (im pretty new to this...but i do know what im doing, for the most part lol!) this is really weird issue..

sometimes when it cuts out, it just cuts a little bit, like a quick studder.....and then 3 pulls later when it cuts its a continus studder for like 500rpm...

this is something weird and im leaning towards something mechanical like spark....due to the fact that when the car was initially tuned this problem did not exist. and now that the problem is there i cant tune it out.

but also im thinking if it was spark...wouldnt this countinue to happen as rpm's rose? or is there just such a load when vtec engages that it could be causing the spark to blow out, before the coil can compensate? or is this a sign of a coil going bad? the ignition system is all stock as of now, with new plugs and he was getting ahold of another set of known good plug wires....

i dont want to advise him to start replacing parts when im not exactly sure what the cause could be....thanks guys!

 

back to the top....lets hear your best educated guess lol! i can post maps or answer any questions, just need to get some insight on whats going on here!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fast2camciv &raquo;</TD></TR><TR><TD CLASS="quote">back to the top....lets hear your best educated guess lol! i can post maps or answer any questions, just need to get some insight on whats going on here!</TD></TR></TABLE>

check your Dizzy for shaft play, if the shaft is walking around in the bushings it might cause misfire or no fire at all. half throttle whould mask this because its not a rapid gain though the rpm's

 

aahh see thats what im looking for! that does make a lot of sense...will check tonight thanks!

any other thoughts???

 

ill definatly check that. thanks. keep the ideas coming