one92rs

iTrader: (5)

ok i had done all the tuning from the sticky. still had a falt spot off idle that was driving me nuts. well darn it after asking five7kid that gave some info i got it. while i was at it i played around with it. ok my engine is a 1992 rs 305. stock internals. hooker headers-magnaflow-no cats or emissions. edelbrock performer intake and holley 600.80457s.
i could not for the life of me get the flat spot off idle to go away. rejetted to find no change. got the transfer slots right. removed the carb and set the idle screw to get 0.20 and reinstalled it. then got a screw bit and a wrench and managed to adjust the rear with it on the car. got it to idle at 700 the best. adjusted the mixture which yielded 22psi vacuum. still a dead spot. tried accelerator pump diaphrams. adjusted the arma million times. finally found a thread somewhere on another forum(have lost it since) with david vizard talking about the accelerator pump circuit. one of the number one flat spot causes. mine had a 31 discharge nozzle. ok so i started adjusting the arm down without checking the 15 thousands. i had the spring almost all the way out which put the accelerator pump diaphram allmost closed. halalooya-just a tiny lil flat spot. installed a 28 discharge nozzle and it came back. adjusted the arm some and still one but less. put in a 25 discharge nozzle and adjusted the arm to specs and i got it. no more flt spot.
stick in a 18 to play and got the backfire for lean. i know there are a lot of people that have a flat spot problem. dont be afraid to adjust that arm spring till itpushes a little more just to test it. if the flat spot goes away then you need the correct discharge nozzle size. they have said to go up or down two sizes. and i ended up with a 10.5 power valve. now this is a stock internal 305. but it will go to any combination.even if it starts with a lean condition put in a bigger one. hope this helps someone.