For the past month or so my 90 4runner with the 3.0 v6 has had an odd issue that I cannot seem to track down.

When I start the truck up it idles like its running on maybe 4 cylinders. When I put it in gear drive off it misses really badly until around 3.5k rpms where it starts to smooth out. However, I am still down alot of power at this point.

If I park the truck and let it sit for around 30 min and get back in to drive it drives like it is brand new for about 5 minutes. After this point it starts to miss and have no accelleration again,

I have replaced all the injectors, fuel filter, plugs, wires, air filter, and ran fuel injector cleaner all with no success.

Does anyone have any ideas as to what might cause this?

Could it be a bad cat at this point?

Thanks,
Nick

 

could be bad cat. also could be the fuel pump "sock" filter clogged.
chances are it's the pcv valve believe it or not. they are a PITA to change on the v6 and it prob hasn't been changed. mine did the same until i changed it.

 

Good point on the PCV valve. Also, make sure the EGR is working properly, I had a malfunctioning EGR valve make the V8 in my pickup act like a 4 cylinder.

And just to be sure, no trouble codes stored in the computer?