Fuel problems I have a 84 toyota pick up truck it wont start i cheked fuel lines distribuator map sensor i changed the computer on it and for some reason the fuel pump doesent have power so i plugged a hot wire to it and started but had to keep revolutions over 3000RPM or it will shut off

any codes will help, but cheking your fuel press regulator its a good idea, remove vac. hose and check for fuel in it, replace if found faulty.

I would clean the sensor. If it can't accurately measure the manifold pressure you will have problems.

is the engine check light on
do you have enough pressure at the fuel rail is the pump running when u swing the engine
is the MAP sensor and crank angle sensor faulty

The Toyota of your year is equipt with a map sensor,it is located on the firewall with a vacuum line leading directly to the intake manifold, This sensor measure engine load and adjust fuel accordingly.This is definetly the problem,make sure the vacuum hose did not come out,Look at the underhood emission sticker for it,it Toyota has a different name for it it might be called boost sensor or pressure sensor.

Have you tried the map sensor? It was a big issue on the early V6's.

time to buy a new van.. umm what about the alternator?

first remove your map sensor and clean it with carburetor cleaner let it soak for a few hours and then reinstall it sometimes they get dirt or carbon build up and the pcm cant tell how much fuel to send

You didn't mention fuel filter in your list. That would be the first thing to change.

Fuel pump circuit (low voltage)
Try replacing the fuel pump relay or testing it if you have the manual.

Hi. Thanks for your question. For issues realted to start up on Toyota 84 xtracab you can visit https://www.reliable-store.com and download the entire workshop manual which includes all the information along with the diagrams for better understanding. Good day!