That Haynes manual is kindling, search FSM and you will find a downloadable version herein. I would recommend you buy the Z therapy SU carb tuning video if your carb skills are as bad as you say. There is (are) no accelerator pump(s) on the SU carbs, so pumping the pedal does nothing but allow more air into the system. Also, put the air cleaner(s) back on and try to start it, the additional vacuum will draw more fuel into the manifolds. Also, drain the tank and use that gas in your lawn mower, there is a plug at the bottom of the tank. This will show how much crap is in the tank. While you are down there inspect the hoses, specifically the vent hoses that run through the cars interior behind the tail light cover panel. Make sure the hoses are soft and pliable, if they are hard and rotten they are a fire hazard and will allow (more) fumes to enter the cabin. Then check to see if there is an electric pusher pump near the passenger side wheel well in front of the tank. Some of the pumps have filters inside, that may be clogged, or the pump itself may not work which will restrict or even prevent flow. This is standard stuff to do on the purchase of an old S30. .