In addition to what Kiwiconehead has rightfully stated, the aux pumps were procedurally switched on only for takeoff and approach on the -300 (just like they are now on the -400). Between climb check and approach check they were only required to run for some abnormal procedures (typically involving high oil or fuel temperatures).
And the engines ran just fine under this kind of treatment.
Maybe captjns could specify which type he is referring to?