vacum secondarys not opening

[superbee717]

ive recently bought a 1980 rx7 with a nikki 4bbl with vacum secondarys. with someone in car idling car i can manually open 4bbls and it works fine. linkage is operating as it should of course jetts are not plugged because i can open them manually. i just replaced the vacum secondary diaphram with one out of a junk yard because maza doesnt offer a rebuild kit or a new one. sprayed carburetor cleaner around vacum lines doesnt seem to have a vacum leak. wondering if anyone of you guys might have a good guess of what i might try next. the car only has 79k miles and runs but doesnt idle very well . keeps cutting off if you let of the acceerator but doesnt run rough. checked vacum lines with a hose to my ear still cant find a vacum leak. also replaced fuel filter. i dont think its a timing or ignition issue because like i said before when i open secondarrys manually it sounds good and runs strong. thanks for any information. i have reached my ropes end.

[superbee717]

i finally figured it out myself. took off vacum secondary diaphram box with three screws holding it on. blew compressed air through the vacum port. it works great now