Correct vaccum line hook ups for 91 toyota pickup 6 cyc

i would check a couple things, the vacuum modulator and the passing gear cable, a clogged filter will not prevent it from not shifting, it would slip instead so that can pretty much be ruled out.
you have the old school 3800 and they have decent transmissions.

google has them under pictures type in vaccum diagram its very detailed

Probably a faulty oil pressure relief valve.

If not done already, you should have an independent oil pressure gauge hooked up to the lube system by a mechanic to check that the high oil pressure reading you are getting is correct. Before doing this change the engine oil and the oil filter and ensure you use the correct oil and only fit a quality and correct spec oil filter.

Click on the following free direct Link. It has the correct Serpentine and Drive Belt Diagrams for your 1993 Toyota Pickup, with either the 2.4L SOHC In-Line 4-Cylinder, 2.7L DOHC In-Line 4-Cylinder, or 3.0L SOHC V6 Engine with the different Engine Options (AC/No AC etc.).

Let me know if this helped, or if you have additional information questions. Feel Free to contact me at FixYa.com!

http://www.2carpros.com/car_repair_information/year/1993/make/toyota/model/pickup/1993_toyota_pickup_drive_belt_routing_diagram.htm

possible check vacume hoses if its hookup properlly

1. Check you antifreeze to make sure it is up to the correct level. Low coolant doesn't make it's way to the heater core thus no heat.

2. IF that don't work, replace your thermostat and one of those things 9 times out of 10 will fix your problem and they're cheap too.

HI, i would advise to check the following areas for faults. replace any part that is fouled or malfunctioning.

1. Check the air filter- This device may be clogged or dirty. replace if visibly fouled.
2. Check the fuel pressure regulator- pull the vacuum hose of the regulator. if there is gas in it, replace the fuel pressure regulator.(if there is no fuel present in the lines, move on to the next check point)
3. Replace the fuel filter and, check the voltage at th fuel pump. you should get 12V at the pump. if its lower than twelve, chekc the ground for corrosion as well as the entire wiring harness as well. all the way to the relay for fualts.
4. Check the Intake Manifold Gasket for worn or damged edges. this ware and tare will cuase leakge. replace this gasket if found to be fouled in any way.
5. Check the freash air intake hose. this hose may be clogged or damaged.
6. Last but not least, check the injectors for leaking seals and, correct pulse as well. replace any injector with a weak pulse or , leaky seal.

it is possible.

possible bad coil at #6