MUSTANGBRKR02

iTrader: (91)

Thanks to everyone! got it fixed

I ended up closing the gap on the plugs which did not help. I swapped the wires and rewirred my whoile fuel system and now it all works.

Car is breaking up at 5500 RPM's and i am looking for some possible reasons. Details are
370 wiseco -11cc pistons
stock 317's with patriot extremes
Speed inc TU1 226/226 588/588 on a 113
TR8 plugs at .028
AFR at WOT is 11.2 to 1 with meth and about 10lbs of boost currently.
SD 60lbers twin intanks with -8 feed and stock return with Kirban Boost ref regulator
car is a t56, Monster stage 4 with a tick MC

It does not matter what i set the boost to at 5500 rpms it breaks up.

Car is still at about 16 degrees of timing.

Just swapped the springs and that did not help.

So.jerZ-28

iTrader: (20)

have you checked pushrods. common for them to be slightly bent and cause misfire/hesitation in upper rpms

MUSTANGBRKR02

iTrader: (91)

All straight. Checked this morning.

mike13

iTrader: (27)

I would try closing up the plug gap.

MUSTANGBRKR02

iTrader: (91)

To what Mike? .028 is pretty close already.

mike13

iTrader: (27)

I would throw a new set of plugs in and gap them down to .022, might sound stupid but have you checked to make sure your rev limit isn't set at 5500?

Chris10an

iTrader: (1)

I'm not a guru in this, but isn't 11,2 to rich? shouldn't you see near 12 in VOT with that boost?

MUSTANGBRKR02

iTrader: (91)

No 11.2 is good and I triple checked the settings for the li
iter in the tune.

98Z28CobraKiller

iTrader: (17)

I agree to tighten up the gap first (I run my NGK 7317's @ .022) to rule out that you aren't blowing out the spark. The AFR should be good. Try eliminating the meth just to isolate the problem. Also, ohm out the wires and check for any pin holes or cracks. Doesn't have to look burnt.

MUSTANGBRKR02

iTrader: (91)

I was hoping that you would find this thread.
I will grab some plugs in the morning and test the plug wires.
It does it with or without methanol on it.
Thanks for the help.

laughatrice

iTrader: (12)

Check your crank position sensor/reluctor wheel you can try and datalog to rule it out. Read my thread hope your problem isn't as bad took me 8 months to find my real problem after I replaced/rewired everything else. You have a 6 speed so that probably means it's not my exact problem but it could still be a bad CPS, wire or bent reluctor wheel.

good luck

https://ls1tech.com/forums/forced-in...ackfiring.html

MUSTANGBRKR02

iTrader: (91)

Well I hope not. That looks shitty.
CPS came out of my running engine.
Stock crank that came out of a running engine.

MUSTANGBRKR02

iTrader: (91)

Well I swapped the WG spring to the 9lb spring and swapped plugs and went to a .020 gap and it still breaks up. I will have new wires here in the a.m.

Any other ideas?>
Fuel pressure only drops 2 psi from steady state to WOT transitions.

99Ls1fever

iTrader: (3)

do you have a high flow aeromtive fuel filter? stock fuel lines? stock rails?

MUSTANGBRKR02

iTrader: (91)

8an feed with dual intank pumps and Speed inc rails with a Kirban boost referenced regualor and stock feed as return.

LS2Ttype

iTrader: (9)

check your wires , my car was doing the same exact thing, i thought it was bad valve springs etc, i had two bad MSD wires, i will never but another MSD product. I swaped them out for Tayler thunder volts , problem solved

MUSTANGBRKR02

iTrader: (91)

Wires are going on in a few when the store opens.

MUSTANGBRKR02

iTrader: (91)

Got it fixed. I believe that it was a bad connection with my 2nd fuel pump but i also put wires on it too.

Thing pulls hard as hell at 6000!!

mike13

iTrader: (27)

If it was a bad connection on the pump wouldn't you have seen lean afr's?

MUSTANGBRKR02

iTrader: (91)

That is why i was trying everything else first because i just couldn't see it being a pump issue with still having 11.2-1 AFR at WOT.

But i also put new plug wires on so that also could have been the problem.

Just glad it is fixed!