747 Engine Start Problem!!!

[Guest joe_walburn]

Must be loosing my mind, but SOMEHOW I'm getting all the way to the engine start and when I click the #4 engine start button, the white center (light, I guess) will not come on and therefore not start when I engage the throttle #4 cutoff lever. Yes, I turned off Autostart and engaged Con ignition, but no go. However, it HAS started in the past so I'm missing something or doing something stupid. Man, is it aggravating!!!Any of you smart kids out there have any idea what this yokel might be doing wrong? I know the default Gate I1 at KLAX is messed up, so I haven't been using it. It's probably something simple, but any help will get you remembered in my Last Will and Testament.Buffaloed in Ohio,joe mahma

[Guest AJ]

>Must be loosing my mind, but SOMEHOW I'm getting all the way>to the engine start and when I click the #4 engine start>button, the white center (light, I guess) will not come on and>therefore not start when I engage the throttle #4 cutoff>lever. Yes, I turned off Autostart and engaged Con ignition,>but no go. However, it HAS started in the past so I'm missing>something or doing something stupid. Man, is it>aggravating!!!Any of you smart kids out there have any idea>what this yokel might be doing wrong? I know the default Gate>I1 at KLAX is messed up, so I haven't been using it. It's>probably something simple, but any help will get you>remembered in my Last Will and Testament.>>Buffaloed in Ohio,>joe mahma1. Did you forget to turn on the hydraulic demand pumps (1,2,3 - on, 4-aux)? This is perhaps the easiest one to forget.2. APU runing and APU bleed on?3. Fuel pumps on4. Electrical bus ties open?5. Packs off (or one on and two off)?Andrew

[Guest joe_walburn]

Thanks much, Andrew. Actually, I'm pretty sure that it was those two isolation switches that let air flow freely between the air packs. But sooner or later, I'll forget one of those other items you mentioned. Appreciate your help and knowledge.Joe Walburn

[Stuntie 0]

Don't touch the buttons, but scan the checklists from Cold to startup to see if anything got missed out.Helps spot the bits you missed, so you can learn to check for then in the future.

[Qavion 19]

"1. Did you forget to turn on the hydraulic demand pumps (1,2,3 - on, 4-aux)? This is perhaps the easiest one to forget."This shouldn't affect engine start however ;)"2. APU running and APU bleed on?"Correct, but don't forget to put the engine bleeds on, too. The engine valves have to be "armed", so that when you pull the start switch, the valves are able to reconfigure themselves to divert bleed air to the (pneumatically powered) starter motor."3. Fuel pumps on"True, but it is possible to start an engine with the fuel tank pumps off."4. Electrical bus ties open?"I guess you mean closed (otherwise electricity will not flow to the right parts).Hope this helpsCheers.Q>