My swap is a '98 two coil 3RZ.
I'm still getting a very intermittent hesitation around 3500 rpms. When I run gas with ethanol I even get an airfuel lean (PO171) code and it seems to run like crap on it with less power. The engine has decent power all around and is very drivable but as I get comfortable with it after break in I have noticed that it won't really ever rev to redline under load if I try and generally lacks power in the upper end above 3800 rpms anyway. The truck also gets like 24 miles per gallon unloaded with 5.29s and 35s which has a few people suspicious, since most guys get 19 or 20 mpg with that setup. If it was a 22re I would almost guess my cam timing was off but since it's kind of a come and go symptom I am scratching my head. I was pretty careful putting the timing chain and gears together so I'm fairly sure that's not it anyway. I have thought about an adjustable timing gear in case the head has been machined alot and I just don't know it to allow a bit more tuning.
I was also wondering if the injectors were just nasty.
Anyone have a similar experience or a possible solution?
