checked compression 150 all 8 fuel pressure 34 psi timming ok engine is a 1995 mpi plugs cap and rotor new back fires worst at 2000 rpm help?

Was this a previous problem or start after plugs, cap, & wires??? Firing order correct???

firing order is correct engine has set for 8 months ran fine before

Run a can of merc fuel treatment and also a quart of MMO in the crankcase .....

whats mmo? i PULLed injecters to have cleaned and flow tesed will install in the morning

Is the backfire coming from intake or exhaust?

exhuast does drive oil moniter not hooked up cause fuel cut ?

mmo=marvel mistory oil, red and black quart can.

Is backfire coming from both exhaust banks?

both banks