my engine is BOGGING.....running like a bag of shit

[streetXtreme]

help!
i just bought a 1986 NA MR2
just replaced the battery and alternator

it takes a few cranks to start the car
but when it starts, it idles around 1500
when warm, idles around 1000

this is the problem
when i press on gas, the rpm DROPs for 2 seconds and then rises like normal
this doesn't always happen

the major problem is when i put it in gear and start driving...the ALWAYS BOGS and never revs up
the car goes NO WHERE
i tried driving it and the fastest it would go is 40km/h

i have a feeling it is the MAF sensor.....i've checked the resistance specification and everything seems ok....
except that AS i open the flap, the resistance goes from 200 ohm up to 500ohms and then drops back down to 200ohm when the flap is fully open....
is this normal?

HELP
what could the problem be??

[danieldaniel]

timing belt? and the few cranks part, maybe you need new spark plug?

[streetXtreme]

i got my car to work properly...!!!
BUT IT ONLY WORKS AFTER IT WARMS UP FOR 10 MINUTES......BEFORE THAT, IT DOESN'T MOVE....JUST REVS UP...

[seanmr2]

check ecu temperature sensor. I think this may be a problem I'm facing right now too. I have a 93T and it runs like crap until it's warm.