Originally Posted by Juleshulings
I was wondering if some had a picture of where to hook up the the vacuum modulator to the manifold? I replaced the transmission in my 89 suburban with an th 400 and need to hook up the vacuum modulator but not sure where is the best place to hook it up at. a picture would be nice.
thank you for your time
The modulator has to be hooked to a full time vacuum source (called manifold
vacuum). On a stock TBI, the correct port should be on the back side between the fuel lines (see below). If you have a carb, the port will usually be in the baseplate but check to be sure, especially if you have a Q-jet.