What are the differences in 90 motors and 91-94?

[92tsifwd]

I Have a chance to get a 90 4g63t motor cheap. I can tell obviously the tb is different and tps and the bov and ic piping. Can I use the 90 tb and tps or due I need to get them for 91-94? Also the bov, other than its visual appearence is it the same? Anything else I need to know about putting a 90 motor in a 92?
Thanks,
Jason

 

[GSX_RCR]

Off the top of my head:

CAS
Coil Pack
Ignitor

 

[bus]

90 also came with an oil cooler. It uses this instead of the water/oil coolers like the 91-94 I think.

 

[RoasT BeeF]

Cas, throttle body and all sensors, cruise control and oil filter housings are different as the 90 has an external oil cooler and 91- has the internal one. The throttle body will work, the cas will work, and the cruise control is the same just mounted in a different spot. So the only thing you will have to change is the oil filter housing unless you get the oil cooler with the 90 engine. If you dont you will have to take the oil filter housing and hard water pipe from the 92 engine and swap it to the 90. You will also have to swap 2 wires on the ECU harness if I am correct. For that look it up on www.vfaq.com. In all honesty it would probably just be easier to take the TB from your 92 engine and bolt it on to the 90. The BOV is the same.

I think thats all.

 

[steve]

the cruise control is the same just mounted in a different spot.

The 89-90 cruise control is quite different. It's electrical where the 91+ is vacuum operated with it's own vacuum pump. the CC computers are different too.

The '90 external oil cooler is considered an upgrade over the smaller heat exchanger in the later cars but with the rest of the parts mentioned use the later versions off the '92.

Steve

 

[92tsifwd]

I would use the 92 tb and cas if I still had them. They will work then? I am keeping cruise and ecu from the 92 so am I going to have to change wires to use the cas and tb off the 90? Also it comes with the 90 external oil cooler and all lines ext. I would rather not change ecu wiring if possible. Also the BOV, is it just as good as the 91-94 because it looks like it is plastic? Thanks guys for the quick responce!
Jason

 

[92tsifwd]

Sorry, I see you said the BOV is the same above.

 

[92tsifwd]

So, do I have to change any wires to use the tps and cas from the 90? I will use the 92 ECU, igniter, coilpack, and cruise control all from the 92. The only sencers I am using from the 90 is the CAS and the and TPS. What do I have to do to make them work with the 92 ECU? If just the wire plugs are different then where can I get the wiring from a 90 and a 92?
Thanks,
Jason

 

[Cesar]

The 92-94 Throttle body will fit a 90 no problem, right? No computer problems or anything right? I'm asking beacuse I think my ISC is shot and I need a new throttle body.
Thanks
Cesar

 

[huafist]

The cams in the '90 are also less aggressive than the cams in the '91-94 models.

 

[GSX_RCR]

The cams in the '90 are also less aggressive than the cams in the '91-94 models.

Really? Hmmm...

 

[92tsifwd]

The 92-94 Throttle body will fit a 90 no problem, right? No computer problems or anything right? I'm asking beacuse I think my ISC is shot and I need a new throttle body.
Thanks
Cesar

I think that you might have to wire in a 91-94 tb plug onto your harness for it to work cause I believe the 90 tps is different. Someone corect me if I'm wrong.

 

[huafist]

I think that you might have to wire in a 91-94 tb plug onto your harness for it to work cause I believe the 90 tps is different. Someone corect me if I'm wrong.

Almost all of the electronics are different from '90 to '91. I went the other way (swapped a 1991 motor into a 1990), and replaced the TB, the igniter, the coil pack, the CAS, and I'm sure a few other things I'm forgetting. Pretty much everything but the O2 sensor, coolant temp sensor/sending unit/ac sensor.

 

[Cesar]

Almost all of the electronics are different from '90 to '91. I went the other way (swapped a 1991 motor into a 1990), and replaced the TB, the igniter, the coil pack, the CAS, and I'm sure a few other things I'm forgetting. Pretty much everything but the O2 sensor, coolant temp sensor/sending unit/ac sensor.

When you say you replaced the items listed above, do you mean you used the items that were on the 1991 motor? Or did you re-use the ones on the old motor??
Thanks
Cesar

 

[huafist]

When you say you replaced the items listed above, do you mean you used the items that were on the 1991 motor? Or did you re-use the ones on the old motor??
Thanks
Cesar

I put a 1991 motor in a 1990, so I stripped all of said items off of the motor and replaced them with the items from the 1990. You CAN use the 1991+ electronics, but you'd have to hack your wiring harness up.