Carb secondaries

[quentinc25]

I had an eldebrock on my 1985 GMC 305 that needed to be rebuilt. The secondary’s wouldn't open and it had tons of leaks. I decided to go head and get a rebuilt Q-Jet (M4ME) to install. The motor runs great now but the secondary’s still will not open. Going down the highway they just will not kick in. One thing I need to check when I have some else in my shop is to make sure when the petal is pushed all the way that I am at full throttle. I will also see if the choke is stopping it. There is a vacuum port that goes into the secondary’s valve on the passenger side. Looks like a T with a port coming out toward the front (currently blocked off), one going into the valve and another into the carb. Does this need to have a vacuum line attached and if so where? I thought the vacuum secondary’s used the vacuum created by the carb when the throttle is pressed and didn't need a vacuum line but just thought I would ask. Any hints or info would be greatly appreciated.

 

[crazy4offroad]

Yes that hose needs to be hooked to vacuum for the secondaries to operate. On your Edelbrock they were mechanical secondaries and should have been operating no matter what, unless the linkage rod came loose.

 

[quentinc25]

Yes that hose needs to be hooked to vacuum for the secondaries to operate. On your Edelbrock they were mechanical secondaries and should have been operating no matter what, unless the linkage rod came loose.

Thanks, I will just need to figure out where to connect the vacuum port to. All the emissions was stripped out of this truck at one point.