1stgeneration89

Last time I posted I had just brought my 89 4runner V6 to the dealer to have the engine looked at. I have been trying to figure out what the misfire at higher RPM and cold temperatures is caused by. The dealership mechanic told me I needed a new throttle positioning sensor and water temperature sensor. I had them replace both things. While they were working on the 4runner I received a call from them to let me know they also found that I needed a new mass air flow meter ($560 :pat: ). I found a mass air flow meter for $65 at the junkyard and went to pick up the 4runner. Replacing the TPS and the water temperature sensor did nothing to fix the problem. I replaced the mass air flow meter and it still ran exactly the same. Trying to accelerate in any gear past 2,500 RPMs, epically when the engine has not fully warmed up is almost impossible. If anyone can give me some idea of the next step I should take I would be grateful. I am frustrated to say the least. I took the truck back to the dealer and the mechanic basically told me that it was too old to really be able to tell what is going on with it. Apparently if you don't own a new Toyota you are out of luck at the place I went to. Too bad it cost me $400 in parts and labor to learn that lesson. If I don't figure this out soon someone is going to get a really good deal on a really nice 4runner. Here is a list of information that may be relevant.
-3.0L V6, 5 speed
-33" tires with stock gears
-Downey Headers
-2.5" flomaster exhaust
-Heads recently polished, ported, shaved and 3 point valve job (in an attempt to solve the problem because another mechanic told me it was a burnt valve)
-Replaced wires, plugs, distributor cap and rotor

CTB

Not sure if this will help or not, but you may want to check out this thread:

https://www.yotatech.com/forums/show...threadid=20571

Scroll down about halfway to a post by Memphis4x4.

Hope this helps, and if not, good luck anyway!