Where is the fuel filter on a 94 toyota pu - 1994 Toyota Pickup

High gear strains the engine more than others, so any tune up item could cause this. Leaking vacuum line, bad air flow sensor, clogged converter or muffler, weak fuel pump or dirty fuel filter all can cause this. I have also seen rust in fuel tank go right through filters and make metallic deposits on spark plugs which will then miss at high speed first and soon at all speeds. Try pulling plugs and "reading" them first. Then test fuel pressure while running at high RPMS.

Under hood, driver side, rear engine area, passenger side of master cylinder, mounted in fuel line ,

You would connect a fuel pressure gauge in the line to the fuel rail with a Tee fitting. I don't think early model Toyota engines had a test port but I could be wrong.
We usually put the gauge in the line right after the filter.

Lack of rpm's i would make sure fuel filter is not plugged and also check the fuel pressure,

cleaning the injectors means more fuel. this would account for having to open the throttle, more air to fire.Try cleaning inside the throttle and the back of the plate. Check your air filter. If it is dirty replace it

right under the air filter. remove air filter housing completely, there it will be

its on the cylinder head!!! check!

Hi there, this is what your filter will look like.

Check all the old ' brittle plastic vacume line connections .And the idle control valve unit located near the passenger side firewall. Over the front wheel cover. passenger side.over.

it is clipped above the framerail just in front of the right rear tire