MustangForums.com - help with a suzuki swift / geo metro

ok, i just got this thing back together after buying it in disrepair and doing a valve job to fix a burnt valve. (its a 1.3 L 4 cyl, the big brother to the 1.0 3 cyl - same engine design). i put in a new fuel filter, new air filter, fresh oil change, new plugs properly gapped, new wires, new cap and rotor, new pcv valve, basically every damn thing is new. i also ended up putting in a brand new gas tank and a used fuel pump / pickup assembly cause my stuff was shot.

well, first the fuel pump wasnt working. i took it back out and after some PB blaster and some bench time it seemed to work ok. i let it pump about 3 or 4 gallons of gas thru it to make sure it was gonna stay working and it went back into the tank. so..... i go to start this thing and it wont fire up. the damn thing had fuel pressure to the injector (yeah it only has one) but it wasnt spraying. i took the injector out and it looked ok, i hooked it up and could feel it pulsing when the motor was being cranked over so i put the injector back in.

bingo it starts (barely). well, the gas i put back in it was about 50/50 fresh/old so i figured this is why it was running like crap. i limp it to the gas station and put 30 bucks of fresh gas in it, at this point it should be about 10 or 11 gallons of fresh to 1 or 2 gallons of old (certainly should run pretty good). still, it runs like absolute crap. i have to press the pedal just the slightest bit to get any kind of accelleration, any further and it just falls on its face - yet when i back off the pedal it has a sudden small surge of power. basically i drove it home from the station by pumping the gas the whole way and every time i let off it gets a little burst of energy.

could it be the fuel pressure is too low? could the injector be half-ass clogged? could it be a throttle position sensor? im pretty frustrated with this thing at this point - its really been a bigger piece of crap than it was supposed to be.