Originally Posted by theg
Hello all .
I have a 3.5 injected old 89model . I was checking vac advance function and have discovered my take off fitting for the vac adv tube on the plennum must be blocked in some way . Does anyone know if this little metal fitting on the top of the plenum which the tube plugs onto has a ball and spring or anything in it . I poke a wire into it and it seems blocked solid . At idle or reving slightly there is no air at all drawing into the manifold through the fitting with the hose disconnected .
It's a plain fitting which experiences manifold vacuum only when the throttle blade is moved slightly open. The hole into the space by the throttle blade is quite small, less than 1mm. Personally, I cheat, and use a 1.5mm bit and drill the sucker out. You can also extract the nipple, its a push fit. Some carby cleaner applied with a thin nozzle may also clear it.