ive tried with two different filters, on two different intakes, and tried with no filter on my ram air intake ...all MAF readings are good in scanmaster ...i guess im goin back to basics with plugs, wires, and fuel pump/filter, even though its all new...ive changed everything else, even though nothing in the scans leads me to believe its missfiring or starving of fuel, i dunno what else to do...ahh im about to buy a daily driver, pull this pos motor, and start over

 

are you sure your MAF isnt maxing out ???

what is the GPS when the power falls off ?

 

I have had this same problem all summer long. At first I had the stock intake, and stock TB, And I had the same problem with the map sensor, I maxed out at 85. So I had the intake ported, and added an AS&M 58 MM TB and went back to the dyno. The power went up about 18 RWHP and the map problem was gone (double checked with a vacume guage). But the power still nosed over and died at 6500 (wanted atleast 7000). So I changed the valve springs, I thought I was going to a stronger spring but they are actually weaker than the ones I had in there, either way the car picked up 12 hp all across the board. So, now I suspect the comp type R lifters I have in there have something to due with it. I am going to have my first set of springs checked to make sure they are with in spec just to verify the last change, then I am going to switch to a solid lifter, maby even change out the XE for something else.

 

okay, immediatly when power falls off, here are all my readings:

RPM: 5325
MAP KPa: 94.9
Fuel trim cell: 15
Lterm counts: 142/141
Sterm counts: 128/128
BPW mS: 16.77/16.86
inj Duty cycle: 74.4/74.8
o2 MV: 928/928
AFGS: 252.39
TPS: 100% @ 4.51V
Spark advance: 33.0
Spark retard: 5.0
knock count: 3432
EGR DC: 0.0 (i have it blocked off)
CCP DC: 5.9
IA temp: 91*
idle rpm: 875
IAC Pos: 89
Speed mph: 75

car is running with no DTC errors, and even though datamaster shows closed loop, its running in PE mode

 

ok i had some of the problems that you are having do you have an lt4 knock module if not get one. second are you running guide plates if you are you should make sure that the pushrods are not hiting the guide plate that makes for a lot of false knock. what type of plug wires are you running i have had the taylor ovc setup and it arced everywere what type of coil, if its stock get rid of it get an msd. stock plug wires work fine or msds i like both of them. and make sure you put in good gas like qt or bp

 

haha...no lt4 KM, i am running pushrod guides, and taylor ovc wires, msd coil....what other wire is long enough to run without getting burnt on the headers?

also, what makes the rockers self aligning or non self aligning? ive been told just to get rid of the guideplates all together, cause they are rubbing, and i cant make them stop

 

self aligning rockers have protrusions that come down and shroud the roller tip so that the valve stem cannot work its way off the roller tip. The non-self aligners do not have these shrouds and would let the valve tip walk off the roller tip shortly after starting the motor.

I have always read that you don;t want to run guideplates with self aligning rockers but instead need to put hardened washers under the stud in their place.

 

make sure your taylors are not arcing in the dark look very closey in pitch black mostly at the front of the engine under the elbow and behind the altenator rev it while you look you should see no arcs at all a blue glow around the coil is normal. guide plates need to be clearanced more the gm guide plate is the best for the job. http://www.thunderracing.com/catalog...vid=4&pcid=250

the round holes is were the stud screws in, the open slots is were the push rod moves in, the guide plates only stop sideway movement. The back of the guide plate slot is what needs to be clearanced NOT THE SIDES OF THE SLOTS. if this is not done the push rod will tap the guide plate and make the motor loud as hell trust me i know

 

Disable the KS and see if that helps.

Rich

 

i did that, its helped...but it didnt get rid of it completely