For as long as I've been exposed to Toyota engines, they've always been smooth, tractable, easily tunable, even-firing and misfireless. Other Jap engines are also great, but Toyota's are usually quieter and smoother (though not always the most powerful--that's a Honda trait). Add to that the Toyota reputation for virtual indestructibility, and that usually makes them my no.1 choice, most of the time.

Until I got acquainted with the 3VZ-FE. Granted, the engine actually runs great, pulls strong and quiet (no doubt, partly due to the massive amount of sound absorbing material in the bulkhead). But the design of the intake system is just a little too quirky for a Toyota in my opinion. It's like Toyota was somehow in a dire need to put out a few "new tech" bits in their 92 Camry so they just dumped a tentative engine design based on the old 2VZ-FE, while the real new item (1MZ-FE) was still undergoing further testing and development.

Basically, my gripes fall on these 2 features:
1. Unadjustable Idle Up mechanism. On the 1MZ-FE, the A/C idle up is adjustable with a hex screw. I hate it when the engine tries to lunge the car forward when I'm stopped in gear (automatic) and the A/C compressor kicks in. My older Corolla with the 4A-FE also had an adjustable A/C idle up valve.

2. Vacuum-operated accessorial startup idle up valve. I really don't know what it's properly called but it seems to do just that. It's that diaphram-operated lever just under the throttle position sensor. It's basically a spring-loaded lever that bypasses more intake air past the throttle valve, which is closed by the intake vacuum (which builds up once the engine starts revving) acting on the diaphram. It makes you look like an amateur pseudo-racer whenever you fire it up cause the engine just revs right up like you were giving it some gas. I prefer my engine to fire up and stay at idle rather than swing to 2000 rpm before dropping back down.

While that may not really mean much to most people, this engine is a bit untraditional in the Toyota kind of way for me. If and when I finally save up enough cash, I just might have a rebuilt 1MZ-FE shoehorned in it's place sometime soon. Now, whether or not I may need to have the transmission replaced and whatnot, I'm just going to have to ask for some expert advice here in the forums.

i have the same 3L engine and yes it does go up to 2000 RPM on start up but I thought that was just normal Engine start up !!

It seems to lack power on start - up as well. But i get power pretty soon afterwards as long as the AC is not turned on as well ! (car has done about 150 Miles)

Vince