First thing is do you have spark, fuel and is the timing belt on correctly (is it timed). You replaced the 25 amp fuse but are the connections in the fuse holder and battery good, clean and corrosion free?
Dan



Lucid's last post on the subject will get you going in the right direction.



One of the first things to check when a 240 just shuts off while running is the timing belt. Look down thru the oil fill hole while someone works the starter, to make sure the camshaft is turning. Even then, it could have "jumped" out of time if loose, stretched, or oily. (By any chance did you just take your foot off the "gas" after accellerating, when the engine just stopped?)

I'd say not to fixate on vacuum hoses or the hissy noise. My recollection is that besides the brake booster hose there are only 3 vacuum hoses on your '87, none of which could make the engine "just shut off".

Engine operation begins with the ignition, which does two things:
1) Provides the spark at the plugs (is that happening?)
and
2) "Allows" the fuel system to operate (no ignition means the Fuel relay doesn't "pick", so the pumps don't run).

Both 1 and 2 above must occur at the correct time, in relation to the positions of the valves and pistons. This means the camshaft and crankshaft must be "in time" with each other and with the ignition distributor rotor.

There are marks on the camshaft, crankshaft, and distributor body that will coincide if this this basic timing is correct. Ask your helper if he is familiar with this principle, or would like further help in checking it out. (A 15/16" socket on the crank pulley bolt and 2 or 3 minutes are all that's needed.)
--
Bruce Young
'93 940-NA (current), 240s (one V8), 140s, 122s, since '63.