This doesn’t include the newest v6’s coming. I.E. the new onslaught from the Lexi, or the 4.0L v6.
Comparing 2vz-fe, 3vz-e, 3vz-fe, 5vz-fe, 1mz-fe
(For the purpose of the discussion 1mz-fe = all 1mz-fe’s, 1mz-fe1 = non vvt-i 1mz-fe’s, 1mz-fe2= vvt-i 1mz-fe’s)
- 2vz-fe – has the weakest parts & should be avoided. 90-91 have o2 sensors.
- 3vz-e – can make good power, but have parts equal in strength to a 1mz-fe, with less power to begin with.
- 1mz-fe – have weaker parts than 3vz-fe’s, and have bad tuning problems with OBD-II that have proven very hard to correct. Powerband past 4000rpm is better tha a 3vz-fe’s, powerband under 3000rpm falls under 50% of a 3vz-fe’s at some points.
- 1mz-fe2’s – vvt-i provides the best powerband of any of the v6’s, start to finish
- The 5vz-fe has proven strong parts, when the TRD supercharger is used, good power can be made. Even safely if you add fuel!
Why the 3vz-fe is superior
Mostly ECU reasons:
It’s OBD-I ECU is the least trouble code throwing, least caring ECU in the line-up. I have tuned 720cc injectors to run on an N/A 3vz-fe acceptibly.
It does not throw/store codes from o2 sensor feedback – even if it is massively different. Black smoke rich to engine melting lean.
It doesn’t care.
1mz-fe’s have horrible over sensitive knock sensor problems. 3vz-fe’s do not.
Like running a mild turbo, or N/A without much in the way of fuel/ignition tuning? The 3vz-fe has the large Denso AFM, and a distributor. Stock, off the bat leaning the AFM cog & adding 7* of timing (17*btdc base) advance puts the 92-93 3vz-fe 185bhp to the 94-97.5 3vz-fe’s 200bhp.
200cc stock injectors are Bleh. But with a combination of a walbro 190+, FPR, and either an extra injector, or larger injectors (330cc @ 41/43psi), you can run up to 300bhp out of one without touching the ECU if you don’t want.
Yes… You can install a FPR, 550cc’s, and a Walbro 255 & use the AFM cog to tune over 350bhp… All without a piggyback. it has been done. You will need lots of money, as you will rich so ungodly rich you’ll get stuck at the gas pump.
The 3vz-fe ECU is very accommodating when it comes to closed loop changes. Don’t like the fact that a normal ECU likes to run stoich under boost until open loop? 3vz-fe’s are not prone to tuning such changes out. If they do, we have it covered with $10. A relay +wire
3vz-fe also has a neat ability, transforming it into what essentially stand alone.
Run the TPS’s output (VTA) through one side of a double pole double throw (DPDT) relay. Take the 5v TPS/AFM supply (VC). Run this through the other side of the DPDT relay.
Trigger the relay however you want, when you want to enter open loop mode. Be that all the time, a $3 ebay boost pressure switch, or an output for your piggyback.
Because of it’s ability to run massive size injectors compared to stock, it doesn’t care!
OBD-I > OBD-II
- easy tuning
- the one fuel trim change do not continue through open-loop
Afraid you’ll miss OBD-II’s anal retentiveness for troubleshooting?
The 3vz-fe has you covered. Tho the ’94 1mz-fe had the world’s first complaint engine/ECU, the 3vz-fe’s do have an ace up their sleeve.
Diagnostic mode II. Yes… The 3vz-fe is the only v6, and one of two OBD-II Toyota’s with DIAG2! This can’t even be entered with the ECU OFF! It has to be done with the engine running! It will throw every code possible instantly. Guess what happens when you trigger it & you’re not moving more than 6mph? Yep, wheel speed sensor code. All your temp & o2 sensors haven’t warmed up? Ya – count all them too. Along with a half dozen other codes.
Anything triggers anything in DIAG2.
All MZ block engine’s have a 139mph hard speed limit.
All 3vz-fe’s have no limit… You need power VS Aerodynamics to do 190mph.
This documentation in no way replaces the Toyota MR2 Repair Manuals. The purpose of this content is only to provide supplementary information to fellow MR2 enthusiasts. Midship Runabout and its contributing authors will not be held responsible for any injury or damages that may occur as the result of practicing any of the methods or procedures described within this website. Article and photo submissions are property of the contributing author.
No idea how old this article is since there’s no publish date… But I must say a very big “thank you” to whoever wrote this. (:
I’ve driven close to 20 different cars, 4 of which were V6’s. But I’ve had my ’93 Camry 300SEi (3vz-fe) for about 5 years now and honestly I’ve never loved any car more… Unfortunately, thanks to some money problems she’s been neglected a bit the last year or two, to the point that I’ve been seriously considering selling my silver baby for something newer.
Well, suffice to say this article has just convinced me otherwise. Think I’ll leave her to stand somewhere safe and sound for a little while so I save up some cash to get everything fixed properly, but I most definitely can’t justify giving up such a beautifully incredible machine just for some quick money… Thanks again for settling the doubts my mind.
I concur. I have had several cars and my 1992 Camry V6 is the smoothest of them all. She has recently been given a “rebirth” due to the fact that when I bought it it had low mileage and was in reasonably good condition. Only 100k in 21 years. I have been completely and totally satisfied. The 3VZ-FE is nearly silken in its feeling. And its so quiet. It puts my Ford 3.0 Vulcans to shame (Which are good reliable engines, but not as refined as this one.) My 20 year old car does not leave me looking for a new car at all. Ill be keeping a savings account for the next car I buy, but this one is sticking around for a while. Good Post.
And what about Toyota’s 1VZ? Very good engine indeed. Simply sublime in its power band. If you’re into the smaller displacement engines with high revving and you want to make your car sound like a Ferrari then just put some pneumatic valve springs high performance cams and it’ll rev to 10,000+ with a beautiful sound to boot. Love my 1VZ.