Toyota Repair: 1991 Toyota pickup fuel pump fuse blowing, air flow meter, fuel pump relay

Question
1991 pickup, 4x4, 22re, 5 speed, standard cab, started blowing 15amp fuel pump fuse. Approx 5k miles on rebuilt engine. Fuel tank and lines flushed, new filter, new pump. It starts and runs at idle only. Fuse blows when given more throttle. Not sure if this is related but it idles high since rebuild. Has very mild EFI compatable cam. Had to shut throttle blade as far as possible and close air screw on top of throttle body to get idle to 950. Sometimes idle will fluctuate erratically. Tried TPS adjustment also.  

Answer
Scott,

If it idles that high there is a vacuum leak somewhere. The fuel pump relay known as "circuit opening relay" in Toyota is controlled by the vane air flow meter. Since it only blows when you step on the gas I would start there first. As airflow increases the vane door opens further. You can replace the fuse with a good multimeter set on amps and see what type of current the fuel pump circuit is pulling. Also, with the key on engine off lift the air box lid off and manually push the vane door open to see if that blows the fuse.