the a/c clutch is probly slipping at higher rpms, you can remove a shim or 2 to buy you some time. i have been running my 99 that way for 2-3 years that way now. my problem was the a/c would work great at start up ,but would quite working when you drove it.
X2 on batterys,starter could be weak also. i replaced good batterys before just to find the starter was weak. you are hearing your vacum pump running. never gas your fuel in an engine that has glow plugs in the combustion chamber, can end up with same results as using ether BAD.
You will want the 1000 amp at least,better yet I have seen them up to 1500-1800 amp also.1 of your batterys are at least 800 amps and it take 2 to start your truck.
just my $.02
My 99 does the same thing.It idles fine cold then when its warm it lopes like a gasser with a radical cam in it. Power seems fine,throttles up quick too,just lopes at idle.Would like to hear what others might think also.:dunno
never use either or starting fluid on an engine has an electiric heating device-air box heater glow plugs or intake heater the results can be very exspensive. just fix the heating problem your engine will love you for it.
only problem with deleting key holes, did you ever drop you keys in water or had dead batterys? pain to get into with no power in truck or key fob not working. just my $.02
removing the insulation on the cold side of the after cooler would actually decrease your milage and power slighty. its there to keep the air that just went through your after cooler from being warmed back up from the heat from the engine be for it goes in to the intake for a more dense intake air.
Instead of using a pump I was thinking fo using a low flow regulator set at about 4 to 6 oz's tapped off of the intake. it wouldn't really affect the boost pressure at all.