We've all read about vacuum leaks and how this affects idling and general performance.

My question, how long does it take before vacuum builds in the engine? While I may have some minor leaks somewhere under the hood, it idles pretty smooth and the performance seems to be fine. Gas mileage is however questionable. Is 20 mpg to be expected after new plugs, wires, cap and rotor, 02 sensor, cat, new temperature sender, cleaned throttle body, new intake hose from AMM to throttle body, new wiring harness, bottles of Techron, cleaned IAC motor, rebuilt AMM, new air cleaner, clean flame trap and a new fuel pressure regulator?

With 200k miles, I am about to the point that the injectors on this 84 LH 2.0 may be drippy (not atomizing like they should) along with all of the accumulated deposits on the inside of the intake manifold. The car always starts, but may crank 10-20 times before firing.

Any thoughts?

Thanks for any help.

p.s. can you tell I like my 'new' car?