bodean

I have a 86 4runner with 22RE and lately my fuel economy has dropped significantly, and at times it feels very underpowered, almost like it is running out of fuel. Any ideas?

Plugged CAT maybe or bad fuel pressure regulator?

How can I test for these things?

Thanks for your help.

az4x4runner

To test fuel pressure, you'd need to hook a gauge up inline with the fuel supply line. Not sure how you'd go about testing a cat, maybe try taking it off and see if the truck runs better? I think the o2 sensor is before the cat, pulling it may also let you know if the cat is clogged, if it runs better with the opening in the exhaust before the cat. Someone else may have more ideas of what else you could check.

az4x4runner

Here is the FSM page that describes testing fuel pressure at the cold start injector supply pipe.

http://personal.utulsa.edu/~nathan-b...28fuelpump.pdf

Jory121

9 times out of ten this problem is the fuel pump...and with a 24 year old truck the pump assuming its oe is prob pretty tired

bodean

A bad pump would cause bad mpg?

PismoJoe

Bad pump would cause inadequate fuel pressure, and all the bad things associated with that. Rough starts, poor mpg, etc.

I would check out the fuel filter as well, its a PITA to get to but it could be clogged

87rustbucket

Check your o2 sensor as well. A faulty sensor could cause those problems.