Quote:
Originally Posted by Z U L8R
sounds about right.
if you can get her back on the dyno and lean out anything below 11.5 a/f's and it still blowing out spark with close to stock ignition timing on your timing map then there's really nothing else it can be other than a bad ground (which you've fixed), a cracked plug (which you've changed), or a bad coil pack arching out under load.
so between tweaking the tune a tad bit or getting coil packs, sounds like the problem lies therein at this point. you've pretty much done everything else you can do.
if your air/fuels never drop below 11 and pretty much stay in the mid 11's where it's breaking up then i wouldn't mess with the tune till you got some different coil packs since all the basic easy stuff's pretty much been covered.
the only other thing i'd analyze/log before i get all crazy would be your charging system.
basically so you can make sure your fuel pump/ecu/coil's and everything else isn't losing juice at high rpm's causing this issue.....
coil on plug is more desirable but some alternatives could be lsx coils, and/or grand national coils, not the brick of 6 which will work but look tacky, but like the msd ones that electromotive uses, you can get 2 from summit for like 50bucks each, then some 8.5mm msd wires, you'd probably be in it less than $200.......
just throwing some ideas out there, best of luck man
Dave
|
Thanks!
Like I said, the tune IS overly rich. It is literally low 10s/high 9s at 18-20 psi.
However, previously, I was running on lower boost (mayb 18 psi tapering down to 16 at redline), and that part of the map was maybe like low-mid 10s (still WAY too rich).....and for 9 months, everything was fine like that.
Now, ever since the first time I noticed the missing, even if I go down to really really low boost (like WG 10 psi), it still starts missing in the higher RPMs.
Will check the fuel pressure gauge during a pull to see if I notice anything....
Also need to look at the alternator.
New plugs is next, see if that doesn anything.
Plugs are not cracked, no oil in wells.
Coilpacks have been fine forever....resistance test showed about 0.7 ohms across the board....good.
Mysterious!