87 5.0 HO low end hessitation when hot

[innerspace]

ok here we go guys
first this 5.0 is in a 87 mark vii so im hopin some of you pony boys have encountered this problem ...
I can run this car cold and she runs like a raped ape , park it for ten minutes and let under hood heat up and she goes right to sh%$t ,
I have no codes on the eec iv ecept broken fuel pump ground (wich i jumped/grounded at the relay in the trunk)
I have replaced
tfi
map
both 02
egr
iac/ias
tps
water temp sensor
cpu / pcm
distributer
wires
plugs
rotor
cap
fuel pump
fuel filter
just about every electrical component there is
i think the only component left is the fuel presure reg

this is definetly heat related, this is acting just like an over heating tfi, so Im begining to think TFI again I did get the new one from autozone so its probably made in china, the only other thing i can think of is a correded ground maybe pullin to much resistance when hot..
any thoughts would be helpfull
thx jb