which 4.3 to get?

sucmah · Jul 25, 2006

My 22re is next to dead and i am going to pick up a 4.3 asap to get me back on the rocks. My question is...which one? TBI...CPI...SCPI...XYZ??
I think the TPI is cheapest and easiest but i think im giving up some HP by going that route, but will i also loose ease of fixing and reliability by upgrading to one of the port motors? I guess what i need is some real world input on which model i should choose and why.

Thanks,

ben

Symon623 · Jul 25, 2006

Ben,
I think you mean..TBI (Trottle BODY Injection)? TPI is the acronym for Tuned PORT inection? Aloota smart asses on here will get uo for it? I like the XYZ though......When does that come out?

I would suggest the CPI/SCPI for it's power and efficiency. The TBI models have decent performance but get as bad a MPG as a FI'd V8? If your really patient try to find a motor out of a Typhoon/Cyclone.....Port fuel infected plus a little spinner thing that adds about 50 HP outta the box and over a 100 HP with minor mods?

I did a swap before and used the stock Toy trans. What a great mod. I'm gonna build another Toy and put another 4.3 in it as well. I also have had a Toy 4x4 with a V8. Awesome but hard to keep cool in Wa. Not down here.

I've done about 6 Toy motor swaps over the years. Good luck.

KarlVP · Jul 25, 2006

I'm waiting for GaryTJ to chime in on this one.

I'll bet ten bucks he says TBI.

crash2 · Jul 25, 2006

TBi is the most simple of them all and the early ones are ther lowest output and have internal vibs until 93-94 (counterbalnce shafted versions)

CPI is junk..

SCPI is the most complex and the best output..

Travis1 · Jul 25, 2006

All I know is, make sure the computer associated with that engine doesn't have the factory anti-theft stuff on it that requires a chipped key, otherwise the injectors won't work.

Would you believe at one point I had every pin, wire color, and sensor reading memorized for an SCPI? 4.3L. Too bad that only stayed in my head for about a week.

sucmah · Jul 25, 2006

Ok, im thinking TBI then since i want to be able to do any trail fixes and such.
I can live without the big power since this rig is crawl only. I guess what i need now is to narrow down what year and model(astro,s-10, ect) i should be looking for to get the most bang for my buck when i get a motor. I know i want a 4x4 motor so i dont have to find a different pan but other than that im not sure. One other thing, crash, you said cpi is junk. Is that because the spider unit is prone to fail?

GaryTJ · Jul 25, 2006

crash said:
TBi is the most simple of them all and the early ones are ther lowest output and have internal vibs until 93-94 (counterbalnce shafted versions)

CPI is junk..

SCPI is the most complex and the best output..

Crash is right. TBI is the easiest to fix, you can get it running with a flasher and a wire if needed. The pre-counter balance motors are fine, they do not vibrate that much and are very dependable.

If you know electronics very well and want the additional power, go scpi. but they are complex to operate and finicky.

cpi has the complexity of the scpi, but not the power and the spiders are always a pain and expensive. Not really much of an option.

sucmah · Jul 25, 2006

What year did they go to roller cams in the 4.3?

no excuses · Jul 25, 2006

sucmah said:
What year did they go to roller cams in the 4.3?

86 I believe, who would run a 4.3v6 in a toy any way, thats just so :rb: :flipoff: :haha:

sucmah · Jul 25, 2006

Hey Stan,

As you can tell im full steam ahead on this now. I think the quads are gonna get lonely for a while. Give you a call tonight to talk some more about this project. I want to be on the road yesterday. And thanks for the answer.

CrustyJeep · Jul 25, 2006

I have a TBI 4.3 in my garage you can take away for $150. Complete with ECU, harnesses, pretty much everything, even a starter. It was on an auto. I think it's an '88 or '89...

I've never seen it run and I cannot make any claims about the condition of anything, but $150 is cheap

crash2 · Jul 25, 2006

no excuses said:
86 I believe, who would run a 4.3v6 in a toy any way, thats just so :rb: :flipoff: :haha:

What stan said

But yes they have ben for a very long time..

no excuses · Jul 25, 2006

sucmah said:
Hey Stan,

As you can tell im full steam ahead on this now. I think the quads are gonna get lonely for a while. Give you a call tonight to talk some more about this project. I want to be on the road yesterday. And thanks for the answer.

Well lets get r done :redneck: , Def need it going so we can go to the Hammers and/or Rubicon/Fordice next spring:flipoff: . Road trip wahooo :cheer:

Trevor · Jul 26, 2006

90% of the rigs we build here get the SCPI 4.3 in them. IMHO, one of the best motors ever built to put into an offroad rig. Good power, GREAT reliability, cheap/common parts. With the exception of one motor, we've never had any issues at all with any of them. No problems on the trails or at comps. Never had any sensors go bad, never had computer issues, never had wiring issues. GM started using a VATS module (chipped key) in 98. If you go this route, you need a computer from 96 or 97. You can use a motor from 96-2001 though. In 98 they changed a couple of pin locations in the computer, so if the harness is 98 or newer, you need to move 3 wires for it to work with the 96-97 computer. In 2000, they changed a handful of things on the motor (including the balancing), which makes it more expensive for parts, and the interchangability of a few items goes away. In other words, stick with 96-99 for the motor. 96-97 for the computer, and try to get a harness from 96-97, but you can use a harness from 98-2001 if you move 3 pins at the computer plug.

Just my .02

sucmah · Jul 26, 2006

Trevor,

Are all 96-99 motors scpi or did they mix some cpi motors in there? Also, do you do your own harness mods or do you have someone strip them down for you? One more thing, as far as i know... all the cpi motors had the aluminum upper intake with the vortec plate on top. Then the scpi motors dont have the aluminum upper, they use the black plastic, low profile intake? Is this right.

Thanks

Trevor · Jul 26, 2006

95 was the last year of CPI, and 96 was the first year of SCPI. I do all of our harnesses.

sucmah · Jul 26, 2006

Thanks Trevor,

That answers my question. One more though, is SCPI also known as CSFI?

Thanks

Symon623 · Jul 26, 2006

crash said:
TBi is the most simple of them all and the early ones are ther lowest output and have internal vibs until 93-94 (counterbalnce shafted versions)

CPI is junk..

SCPI is the most complex and the best output..

I've heard negative things about the CPI as well, but never experienced them? What is the diff between CPI and SCPI? I have access to a 4.3 but want to know what to look for?

As for the power?...Dude you can never have too much....:redneck:

sucmah · Jul 26, 2006

Trevor,

How do you reprogram the computer to eliminate the post cat o2's and the egr and such.

zig80toy · Jul 26, 2006

Hey, can you start a build up thread in the garage section when/if you do this? I'm pretty sure i'm not the only one who would like to see some pics of a nice 4.3L being dropped in a toyota. Please explain what was easy, what was hard, what parts had to be homemade, etc... This is probably something i'm am going to do in the future as well.