I fixed it electrically, but I get no fuel out of the top of the injectors, So there is no fuel in there to preheat.
You typed "
injectors" (plural). Please clarify. I ask, because a typical
manifold heater has only one. And there are two types; my Yanmar had the little fuel bowl like Bob described. It relied upon gravity and intake vacuum to deliver fuel to a single manifold heat plug (as opposed to multiple
cylinder glow plugs), and I had to fill it periodically by hand. The return line type also relies upon gravity, but not quite in the same way.
Your pump delivers fuel to the cylinders under high pressure, hence the steel lines. But what's delivered is more fuel than the cylinder needs for a single detonation. What's left after the individual injectors take what they need back to the fuel tank via those low pressure lines. So when the engine is running, fuel is always moving in a loop; low pressure to the pump, high pressure to the cylinders, low pressure back to the tank.
One of these low pressure lines is hooked up to the manifold heater plug. But note that it's not in the loop. Once it's full, fuel sits there waiting to be used when you need it for the cold start. You must manually activate the pre-heater either by keyswitch (HEAT position) or separate push button (keyswitch ON). This energizes the heat plug. Once it's hot enough, you turn the keyswitch to the START position. This creates intake vacuum, which in turn sucks fuel out of the return line and past the heater. It ignites, and pre-heats the air that is destined for the cylinders. The hot air mixes with the cold high pressure fuel, and - ideally - detonation occurs. The colder the ambient temperature, the longer you have to pre-heat. Occasionally it takes more than one pre-heat cycle.
Both manifold heaters and glow plug systems can also be re-energized while a cold engine is trying to get up to speed. Some systems call this "after-glow". When your engine has started - but is sputtering and not all cylinders have caught yet - turn the heater back on. Sucking more hot air into the cylinders helps cold cylinders catch up with those that are already detonating AND cuts down on the amount of white smoke that comes out the exhaust.
Oh yeah, and set your hand throttle at 50% or more
prior to these cold starts. Once the engine catches, you can then decrease throttle as it warms up.
//greg//
