spark, timing, fuel???
 

To start my setup is z6 block, y8 head. 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.

Re: spark, timing, fuel???
 

come on people help a brotha out! im the one doing the tuning on this....i have a few ideas but would like some second opinions before we start replacing things....wondering if anyone has had something similiar happen..

Re: spark, timing, fuel???
 

when you say tighter, how much tighter? check your cap and rotor, may be on its way out. dont know if its causing it but it doesnt hurt to check. i dont think boost cut works with CROME ;)

Re: spark, timing, fuel???
 

gapped to .28

Re: spark, timing, fuel???
 

did you check cap and rotor? possibly bad ignition system causing some ignition break up

Re: spark, timing, fuel???
 

no i havnt. i might just replace the cap and rotor since its not that much anyways.

Re: spark, timing, fuel???
 

yes it does. i currently have a car ive tuned that has been saved from some severe boost spikes by a 10psi boost cut.

Re: spark, timing, fuel???
 

im pretty sure its not a boost cut unless that came from the tune. cuz it never did it before and ive spiked to 19 before with no cut!! plus it doesnt sputter/cut every time i go through a gear. sometimes it will do it bad and sometimes ill go a hole night of racing with no cut....

Re: spark, timing, fuel???
 

I have the same problem on my d15z6 NA. Some time it is OK all night and some times it cuts, stalls like there is no fuel or some thing. It hapends betven 2000-4500. I instaled larger diameter intake tube, changed plugs, vires, and every time the problem is here, then it is ok and that way for over a year now. After instaling a 70mm intake tube thing become a litle beter but still present in a daily drive. My frend said i have ghost in the engine.
I am not shure what will pahend when I install trubo.

Re: spark, timing, fuel???
 

wierd im gonna try and change my wires asap cuz they are some bigger ones that are made by "forza". very cheezy and the outsides look like aluminum foil. i hope it helps

Re: spark, timing, fuel???
 

Just get OEM wires.

And tell us if that fixes your problem.

Re: spark, timing, fuel???
 

Post your map and post a datalog of it occuring and maybe I could help.

Re: spark, timing, fuel???
 

ok xeno i will post up the map tonight when i get home....i havent datalogged since the initial street tune (ill see if i still have it saved) but it wasnt doing it then...thats what tells me its something mechanical and not in the tune....

his ecu doesnt have a header at cn2 so i dropped mine in during the initial street tune. i should have logged while it was hickupping but honestly i didnt think it was nessecary i thought i could tune it out without having to datalog.

if indeed you think that it could be seen on the log then maybe this weekend we can set it up and get a few logs for ya. during the pull the a/f's are rock solid, thats what leads me to think its ignition....

Re: spark, timing, fuel???
 

I had a very similar problem... still haven't figured it out. Seems to happen much less in colder weather, but it still happens occasionally.

I've datalogged the problem before, and it showed up as lean spots (misfiring) when it occurred.

Re: spark, timing, fuel???
 

Try a new coil/ignitor setup. Or swap in a known working dizzy.

My sister's car did the same damn thing, then started throwing code 9. I ripped apart 2 good dizzies to make 1 good one to fix it.

Re: spark, timing, fuel???
 

All good advice so far. Deff an ignition problem.

Jagojon in right, it'll just show up as a lean spot (misfire) on a datalog.

Re: spark, timing, fuel???
 

ok. well now the thing is its a y8 head with i believe a z6 dizzy and its ghettofied. the kid before me forced a bolt. only has bolt holding it. how hard is it to put a y8 dizzy on there? as far as wiring etc?

Re: spark, timing, fuel???
 

Just grab any OBD1 DX/CX dizzy and it will fit the Y8 head and still have the OBD1 wiring harness.

Re: spark, timing, fuel???
 

really? but the z6 doesnt?

Re: spark, timing, fuel???
 

Yes, the Z6 is the only one that is "gay" between the d-series and doesn't bolt up. Atleast in my experiences.