Thread: low engine vacuum at idle?

Tweet

Originally posted by severedties
i have pretty much the same set up with the 350 ho motor. but i chenged the heads to dart iron eagle's. and i to have low vacuum about 11 inch pounds. the gauge is reading from below the blower. the power brakes dont work good. should i run a canister? this setup is on a 72 suburban 3/4 ton.

when you are idling with a blown motor you should have vac. in the manifold. most boost gauges are boost and vac. gauges, so you can see both vac. and boost. you cant run nothing off of the intake like brakes, because of the boost. the vac. should be about the same thing above or below the blower when the motor is idling. sounds like to me you have a vac. leak.