I have a 94 TA with the mods in my sig. I recently installed new plugs, taylor wires, optispark in an attempt to get rid of an high rpm miss that happens right before my car shifts on the 1-2 and 2-3 shift. I have rechecked my rocker arm nuts for correct tighteness. But I still have this dern miss i can't get rid of. Today i bought a fuel pressure gauge and at idle with vacuum line connected it is about 40, drops as soon as you give it throttle. With the vacuum line unconnected it goes to 42 but still drops when throttle is applied. This is all In park, haven't attempted to drive it yet but I don't think this is the correct pressure. Is it supposed to drop when you go to wot with the vacuum line connected, please help me out this problem is driving me absolutley insane.

 

Something sounds wrong.

Turn the key on, but don't start the engine.... what is the pressure? Should be 41-46psi.

Remove the vacuum line (plug it), start the engine.... what is the pressure? Should be the same 41-46psi.

With the engine still running, connect the vacuum line... what is the pressure? Should drop proportional to engine vacuum, about 6-8psi on a stock cam, at sea level. You could see 35-38psi on the gauge.

Tape the pressure gauge to the outside of the windshield (if its a mechanical "test gauge"), take it out on the road and drive it. Pressure should vary with vacuum/MAP, which means when you back off the throttle and coast down, the pressure will go below the "with vacuum" idle reading (will read 35psi or below), and when you snap the throttle open, pressure should jump up closer to the "no vacuum" reading (41-46psi). Then take it WOT, and the pressure should hold at the "no vacuum" reading all the way to red line.