We would have to investigate which (vital) step you are currently missing, Razor.
Be aware that e. g. Mark's checklist is an altered procedure when compared to the checklist in the manual (which is the rw counterpart), but both ways should lead to running engines of course.
The main procedure is to establish external power and air, distribute it through the plane and later get self-sustaining with two engines running, starting the other two then with the power and air 'coming out' of those.
Maybe I can describe the stuff with some pictures, using the checklists from the manual (which is
manual3).
Starting with loading your plane, setting up the fuel load and getting it correctly parked. So you may open the doors, apply the chocks and, very important,
enable the external power and air.
As we don't have any APU available, you will need this to get power and air for your systems and the AC into your plane.
You switch your battery to
on and run through the
checks of the levers and switches in the cockpit, which e. g. includes setting the start levers to
cutoff position and checking the flaps lever and the one for the gear.
To
achieve the external power and air being distributed throughout the plane, set up these things. Note the blue 'PWR on bus' light and the switch for the external power being in the
upper ON position (which needs a right click).
The air pressure readings should both be active, low and high pressure.
Make sure to have the wing valves
opened or the air won't reach the engines. For starting, leave the bleed air valves
off until 3&4 are running, then open them to get pressure into the system for the start of 1&2.
While on the ground and
preparing your flight, the galley power can remain on and also one AC unit can run. The ones on the 707 are electrical driven, so they draw quite some power from your ground power unit.
That's one reason to turn both things off just before engine start. Equipment cooling
NORM and the planned cabin altitude and temperatures can be set now.
Hydraulic pressure needed? Use this setting to e. g. get some brake pressure.
For the flight and in regard to your fuel load, set up the pumps there.
The setup on the Overhead mainly includes the lights and the engine start control switches. Also choose the LOW PRESS setting for starting.
You see the GRD position on the #3 engine switch being marked there.
Don't turn the switch yet, but this is the position to choose for starting her later.
Now or just after getting power to the plane, you set up all the navigational things, align the INS, watch the charts, set the speedbugs and so on.
Getting closer to
engine start, close the doors of the plane and make sure to have your INS aligned and set to
NAV, the INS/Doppler to
INS.
As said, before attempting to start, turn
off the galley power and also
any AC unit, set the beacon to
on and also the passenger signs.
Then rotate the engine #3 start control switch to
GRD and watch the
N2 gauge to reach approx
15%.
Then switch the engine start lever from the
cutoff to the
idle position and wait for #3 to ignite it's fuel.
This picture was taken just after the ignition, so the N2 value is much higher than 15% there. Don't get distracted by this, please.
Ok, #3 should be running and you are still on external air supply. So you can start #4 now, in the same way. Around 15% N2 means 'fuel on'.
Now, we want to get rid of the external stuff, so we get the #3 and #4 generators online and on the buses and also make sure that those two running engines now supply our air pressure system, otherwise #1 and #2 won't start after the external air is gone.
So make sure to set the switches like this.
When done and checked, disconnect the external power and air.
You should still have some low pressure readings then (as 3 and 4 now produce pressure) and also enough power, your are self-sustaining now, so they can push you back and stuff.
Starting 2 and 1 then happens like 3 and 4 before. GRD START switch to
OFF after this.
After all engines are running, set the galley power, the air compressors on, the engine bleeds off and the AC units both to on. Pressure and power are sufficient enough now.
Things like the radar, transponder, stab trim setting and all the lights are up to you. If you've used the hydraulic interconnect before, you can disable it now.
Before takeoff, turn off the #4 air compressor, turn on the ignition for all engines and also don't forget about the window and pitot heating to run. Clock:go!
At a safe height, the ignition is weather dependant, but can go to
off.