dmahonec

I recently bought a 1990 4Runner 4x4 with the 3vze motor. The guy I bought it from said that the motor was actually a 1993 3vze that was swapped in. However, when I changed the cap, rotor, plugs, and wires, the parts that I bought for the 1993 engine didn't fit properly (screws on outer rim of dist cap were off). I went back to O Reillys and bought the 1990 parts. Figured what the hell, worth a shot. Well, it ended up fitting. Not only that, but the wires for the 1990 motor were much more similar to the ones already installed, which were nice, thick wires (1993 wires were skinny).

Anyways, ran the check engine light flashes and came up with code 52, knock sensor. Which would explain the low idle, low power, and occasional stalling when I hit rough snow patches or something like that. So I've looked into buying a new knock sensor and wire online, but the experience I had with the dist cap has me wondering if the engine is actually a 1990 stock motor, and the guy just had no clue what he was talking about. Is there ANY way to tell which motor I have? Any sort of telltale sign that would let me know "Hey, you've got THIS engine."? I would really hate to order the wrong sensor and find out when I go to swap it that it's the wrong one. I've checked the UPC on Oreillys website for the two knock sensors, and they're different, otherwise it wouldnt matter. Any ideas?

MudHippy

What he most likely did, or had done, was install a 93 long block using the stock(90) electronics. That would be the easiest, cheapest way to swap in 93 motor. Because there's little or no compatibility between a 90 and a 93 3VZ-E electronically. Many things changed like the distributor(and the rest of the ignition components), the ECU (and wiring harness), and the knock sensor(and knock sensor "pigtail" wire). But you can swap all of those things from a 90 onto the 93 without any issues(or vice versa, but you'd have to drill out the pilot hole for the distributor so it would fit in the 90 head). So, since it has a 90 distributor on it, it more than likely has a 90 ECU(and wiring harness), and a 90 knock sensor + wire too.

The telltale sign it's a 93(or later) long block is the timing belt tensioner. If it's got a hydraulic tensioner then it is. Earlier engines have a spring loaded tensioner.

dmahonec

I've got a hydraulic tensioner, but like you said, if the cap is from a 1990 than all the other electronics should be as well. I guess I'm going to go out on a limb and buy the 1990 knock sensor and pigtail. Thanks mudhippy, very helpful and informative!

MudHippy

The other way to tell what knock sensor you have would be to check the knock sensor wire connector, where it connects to the wiring harness(since the other end is impossible to see w/o pulling the entire intake). The connectors are different(which is the only real difference). Then you'd be 100% sure. Or check the part number on the ECU to verify it's from a 90. Both would be fairly easy to do...know that I've thought to mention them.

The details on all the knock sensor + wire differences are here:
https://www.yotatech.com/51613262-post6.html

70elcoss

Well the block and heads are identical.... When I hydrolocked my motor the block was no good so I bought a 93 T100 short block that a guy had in storage for years and I rebuilt it using all my 1990 accessories.... Heads, timing components, electronics etc.... I basically needed it just for the block so I can tell you they are all identical with the exception of the wiring and timing components but you can swaP them out so yea it probably is a 93 motor but he used most of the accessories off his 90 to make the swap easier

jbtvt

Yep, I was all set to swap out my 90 igniter for a 94, screwed it down, went to plug it in and... no love. Very tempting to whittle away the two plastic ridges impeding my effort but figure the engineers must have put them there for a reason. That will make my eventual swap more difficult, should have done my homework.

What's the alternative to reusing stock electronics - rewire everything at the ECU plugs or is there even more involved?

dmahonec

Just ordered the 1990 knock sensor and sensor wire. Should be here within a week or two, I'll be sure to post back with the results, and I'll try to take some pictures while I'm in there for informational purposes
Thanks everybody!

maxscott

[my pig tail look good put a new knock sensor in but later found the pig tail was shorted ..