Re: MerCruiser 3.0L 140 No Acceleration
Your guy said problems arose after the ignition change, so re-check everything, carefully. Verify that TDC is true, by manually cranking engine to max rise of piston #1, with screwdriver or depth gauge in spark plug hole. Verify that the timing mark is at 0 degrees, and the rotor in the distributor is pointing to #1 plug wire.
Remove plugs, line them up in a grounded row in the correct firing order (wrap the threads with one piece of 14-ga bare copper, screw down 1 end of the copper to a good ground), crank with key-start, verify they are sparking in order, one end of the row to the other).
If all's well so far, remove the dist'r base plate and check that the spring-loaded timing advance arms move freely and that their springs are intact.
If still not found, swap out with a good replacement distributor (if points & condenser style, clean & gap the points correctly), and again verify TDC is right.
If still no cigar, you've missed it again, OR if you are certain you've checked correctly, it's a completely different problem. You need fuel, spark and compression, all at the right times. Check compression, that's the only item you haven't touched yet.
A PS thought/question... breaker points misbehave badly and result in gross random missing/misfires if the distributor shaft is worn (because the points gap bounces all over the map with excess radial play). Does your electronic gear require precise and constant centering of the dist'r shaft?
