LSwonderfull

[QUOTE=Old Geezer;10075279]Im not sure i am looking to others for there experience with this, i will call Callies if i dont hear back from MSD soon. Its been 3 weeks and no reply yet as to my problem btw.

bluecajun5.3

iTrader: (31)

i would try backing down the timing.
34 is a lil high on pump gas with these engines.

LSwonderfull

ok so you are suggesting that this seemingly chaotic missfiring is caused by detonation? It acts like a missed timed spark occurence like a crossfire from a bad distributor.It is pretty violent

Shawn MacAnanny

iTrader: (12)

yeah 34 degrees is alot of timing. im running 28.

LSwonderfull

I ran 28* too until the dyno showed it was worth more HP and torque every time i added 2* OF TIMING. It kept gaining all the way up to 34*

BOBBY BATES

34 degree of timing is also where i found my most power on the dyno yesterday..i also ran mine up to 7300 once just to check for a miss fire for you, and i had no problem....

LSwonderfull

Ok i found my problem, with 34* and 91 octane the engine goes into uncontrolled combustion. First i pulled timing back to 26* total and it revved clean to 7500 rpm, next i pumped out all the 91 octane and poured in VP C-16
and set the timing back to 34* and it ran flawless clean to 7500 again. I am planniing on running 34* with a blend of race and pump gas.
Thank you everybody for helping me with questions and advice!

Pro Stock John

iTrader: (34)

Interesting.

LSwonderfull

TTT The problem is back UGH! Any one have any pops or ignition breakups with LS2 and 24x crank ? Does the crossed wires for cam sensor cause odd reference issues intermittently?

99tramsamc/fia

iTrader: (2)

Did you find the problem, yet.
I am Having the same problem!
I run basically the same combo carbed ls, Modded 750 holley, super victor, large hyd. Roller(@.05 262 272) W/ 34* timing
My problem is at random RPMs sometimes 7000, sometimes 7500.
This is with the stock crank, wheel never removed.
I am currently going back to the stock ECU to control timing.
I used 2 different MSD 6010 boxes on the dyno to see if that would fix it, Nope
1 of the boxes made 20HP more then the other.That Shi! is junk.
Ing box just shuts off. Seen it with the timing light.
It is not valve float for sure, you can see that clearly on the dyno.
No det. runs on c-12 race fuel.
Seems to me like the box cant keep up with the high rpm higher timing setup.I know on my FAST box there was a reference angle for the crank sensor, that needed to be a min of like 10 degrees more then your max timing to allow the computer time to make up its mind.
Just throwing out ideas cause i know how you feel!
Please let me know if you get it figured out.

WhiteLTone

iTrader: (18)

are you only seeing this problem under a load? or does it also exist free revving the car? im chasing down a similar problem w/ my car, just a little lower rpm. mine hits a wall at about 6k rpm, lags there for a while, not like a misfire but more like its having trouble pulling and then will eventually pick up and go again at around 6400, and it runs clean up past 7500. i called and spoke w/ msd today, they werent helpful. i check fuel pressure, also have experimented w/ timing ranging anywhere from 27 deg all the way up to 36 deg locked out w/ 110 race fuel and tr55's gapped at .050. im leaning towards valve float but im not sure, it may be an issue similar to yours. i have a new crank position sensor as well as new wires, the box is supplied power and ground directly off battery and seeing 14+ volts the entire pass. Mine however only seems to happen in the top of 2nd and 3rd gear (th400). it rev's fine free revving, and during the burnout in 2nd and 3rd gear.

i hope my post was somewhat informative to you, also on my wideband the car isnt going lean or rich spikes at all. It seems we have similar issues. Hope we can get it worked out.

LSwonderfull

I get my pop during the run only, never on the burnout. It is like the MSD box gets confused, i wonder if its a lack of capacitor internally that could cause this. I wired the car to run on a 1998 F-body PCM it seems fixed but im waiting to run it at the track(weather). I am confident the problem lies with the 6010. GM has adjustments to coil dwell based on voltage and other features that must play a part in preventing this problem. My pop/breakup happens most on 2 to 3 shift. I turn 7800 in the traps, the problem happens below this rpm. On the engine dyno this problem would happen at peak power 7100-7200 rpm. The engine would miss so hard it would jump up and down on the dyno stand and blow the airflow meter off the carb. I have replaced the 6010(out of pocket) and replaced the crank sensor and both bought a little time before problem reoccured.Im done with the MSD box and now i lost rev limit of ignition feature. Does anyone know what the GM PCM does at 8k to limit rev? Ignition kill? I know it cuts fuel for lower range rev lilmit which with my carbs , so that is useless to me.

EHat911

iTrader: (15)

when you buy your Crank sensor do it get it for an LS2 or and LS1 because they are different i cant remember excatly but im pretty sure the LS1/6 sensors is black and the LS2 is grey, also what lifters are you running u said u run a hyd roller and even tho people say it works their really not meant for anything over 7000 that can also be an issure your having in u may be collapsing a lifter also detonation can be pretty violant if its detonating real bad...