So about a year ago I dropped a reman motor with ENGNBLDR head and 261C cam into my 4Runner. It ran pretty well for 4 or 5 months (though I never quite felt it had as much power as it should, but it IS a 22RE...) but for the last 6 months or so, it hasn't been running right and I'm going insane trying to get it figured out.

It gets terrible gas mileage (like around 12), but it was really bad even before I swapped the motor.

The idle is really rough when cold. The stealership told me that the wax piece in the throttle body which is adjusted by the idle screw is bad, and that's what's causing the rough idle. I'm not too sure I believe them, but I just thought I'd throw that in there.

Then after it's warmed up for a good while, there's a flat spot in the powerband at wide open throttle from the low 2k's to the low 3k's. And at really light throttle it will kind of stumble and hesitate.

I've checked/tried a lot of different things, but before I get into all of that, I'd like to hear some opinions on what people think it could be BASED ON THESE SYMPTOMS.

I really need to get this thing back in shape, so whatever help and advice you can give is MUCH appreciated.

 

The possibilities are almost endless! Its very difficult to diagnose such issue via internet. You will have to do some testing and eleminate problem areas to be honest.

Bad ignition, timing, vac leak, bum injectors, bum/low fuel pressure or volume, MAF, CTS, ECU connection, compression etc etc.

 

A rebuilt 25 motor will only run as well as the components around it. If everything else on the Toyota has not been checked/rebuilt/replaced/renewed then just rebuilding the motor won't solve your problems. TPS, MAF, injectors, ad nauseum of the things that could be causing your issues.

:wabbit2:

 

Sure, I understand all that. I swapped the motor because of bad compression and shoddy work on a rebuild from the PO. I guess I might as well lay it all out for you guys...

So the TPS is new and I did my best to adjust it per factory specs.
Injectors were professionally cleaned when I did the motor.
Timing and valve adjustment are correct according to recommendations for the head/cam.
O2 sensor is a new Denso.
Also put in a new cat about the time I did the motor.

The things I'm still suspicious of are the AFM (it was opened up and messed with by the PO, so for that reason I've also tried messing with it), maybe the coil, vacuum leaks, possibly other fuel issues... Anything else I'm missing?

I'm a little hesitant to blame the AFM because when I had the emissions tested, we adjusted it to the best position as far as emissions were concerned but even that just barely leaned it out enough to pass. That also makes me doubt a fuel issue because of the richness...

Any other ideas??