Need advice!Engine bucks at 5000 rpm

:confused: My 86 Gt was breaking down at around 5000 rpm with the stock injectors.I installed 30 lbs injectors and a mass air calibrated for the injectors.The fuel pressure is 80 psi at around 8 lbs of boost it still bucks and jerks at 5000 rpm.Would this be a fuel problem or ignition.I still have the stock ignition with a msd blaster coil ,motorsport wires and new plugs with a heat range colder.The dyno in my area the wide band o2 they used is not working.so i xcan,t really tell if it,s a rich or lean condition.Pulled plugs insulator is white tip is a greyish color.Any help would be appreciated would like to take itto the track this weekend. ....I have total advance timing set at 32 with thw boost retard at 1 Any advice would be appreciated...

Be more discriptive of the bucking. Is it like you are hitting a rev limiter or does it just bog out and fall on its face?

Probably spark blowing out since you don't have a ignition box. Did you change your FMU disc for the 30lb injectors? What SparkPlug brand and Plug Number? Have more questions but this is a start.

80PSI??????????? :eek: :eek: thats alot. With 16psi i run less then 60psi with 38's. Why are you pushing the 30's so hard? :confused:

what are your plugs gapped at? I agree, you are probably blowing the spark out.

What are the plugs gapped at? What's your timing? Are you running a btm?

I'm Running ford plugs awsf 22 with 1 heat range lower than stock.gapped at 32.I am running a 8 to 1 disk .Will be changing to a 6 to 1 for the 30 lbs injectors.Was running the stock 19lbs witha 12 to 1 and was running over 100psi under full boost.But i am having the same symptom at aroud 5000 rpm with the 30 as the 19 , it jerks like it,s cutting out the rev limiter is 6200 so i am not hitting it.i have the timming set at 10 with the boost retard at 1. I am running 9.5 to 1 compression ratio ,Now i might thinks it,s a bit high for boost.might have to try a msd 6al.It works great until it,s starts to miss.Would like to get a low 12 this weekend ran 12.7 on the engine alone.Thanks guys **Also the msd boost retard as a a setting on the side with numbers on it.I have it set a 0 where should it be?