87 buick lesabre eng miss


new coils, ingination module wire , plugs, did compression test all sixx good avg. ragne between 135-160 miss is at all time any speed not just at idle


Bad fuel injector, or intake manifold gasket leak. Spray carburetor cleaner all around the intake manifold gasket to see if it changes anything.


My opinion would be to connect a vacuum gauge to the intake and see what’s going on.

Sorry, but 160 PSI is a bit weak, but tolerable.
135 PSI bites. Not only is that low, but you have a 25 PSI variance here and that is not good; especially on a 3.8.