[freez]

i have a 76 280z that is running rich.the car was idealing rough but i found the srew on the afm was loose.i turned the big black gear looking thing till it smothen out.now the car idols smooth and rev up quick.but when i put it in gear and try to take off the car starts to back fire.and runs really bad till about 4500 then smothes back out.could my timeing be off or my coil be weack.my fuel pressure regulator make a hissing sound and i was told that it could be going bad or is bad.would a bad regulator make it do this.does the thermotimt switch only control the cold start injector.or does it do some thing else to.any help would greatly be apprecated
thanks

 

[bakachan]

backfiring means too lean. look for a vacuum leak. first place to start looking
is the big rubber hose between the afm and the intake manifold.

fuel reg hissing is normal sound

fix vacuum leak and
try advancing the timing and see if it runs better