Jumping in to the 3.0/3.4 swap

Rocketwrencher · 09-04-2008, 06:11 PM

I am in the middle of rebuilding my 91 22re truck motor and my 16 year old comes home last week and says the CEL is on in his 95 3.slow 4-runner. So I check it out and sure enough, chocolate milk. The motor has 157000 miles on it and we are the second owners of the truck so I thought I would give the dealer recall a try. No such luck. The origional owner had it done in '91 and the dealer said they will only replace it once. So I started checking around for rebuilds versus rebuilding it myself and I came across a guy selling a 3.4 out of a rolled Taco with 90,000 miles on it and he is only asking $300.00. I just about s**t my pants! I called immediately and suprisingly enough, he still had it.www.offroadsolutions.com/products/ I pick it up tomorrow, That is if he doesn't sell it under my nose or read any of the articles on this site before then. He doesn't have the wiring harness for it, so will have to scavenge a junkyard truck for that. My son is pretty excited. We plan on rebuilding the motor before we drop it in just because I don't know what the motor has been through, but at that price, I think it is the smart thing to do. Any ideas or thoughts from those who have been there? By the way, we live in the liberal state of CA, so will have to put up with the smog regs. Here is a pick of the motor that will soon be replaced....I hope.

I have to go to football practice now but will be back online tonight at nine if anybody has any thoughts or suggestions.

Rocketwrencher · 09-04-2008, 06:14 PM

By the way, If I am able to get the motor, This 3.0 is for sale whole or parts except for the items that I need for the swap. Let me know if you need any thing.

3yotys · 09-04-2008, 06:42 PM

Man GO for it!It will 5 &10 you till broke but it's worth it.Take that 3.0 to the scrap yard.
Bigblock

mt_goat · 09-04-2008, 06:43 PM

Here's a section full of reading for you:
http://www.yotatech.com/f160/

RobD · 09-04-2008, 09:10 PM

Plus this: http://www.andrewzook.com/content/view/22/48/

You'll need to save the oil pan, pickup and dipstick tube from the 3.0 and swap them into the 3.4. Don't cut the alternator harness, just tuck it up away.

You're going to need to move the battery over and have an exhaust crossover fabbed or do it yourself. The wiring isn't that tough, once you know what the end goal is.

Feel free to ask questions. Mt_goat, Elvota, me, and a bunch of others have done the swap. Mechanically, it isn't hard. Even the electrical isn't too bad.

And they're a lot of fun to drive, once they're done.

abecedarian · 09-04-2008, 09:17 PM

and don't worry much about california smog regs. if you get all the wiring, ecu and smog stuff on the 3.4 taken care of, it's a few meetings with an arbiter/referee and maybe a few hundred bucks and you'll have an exemption for the truck with that engine. cali is actually pretty straight-forward: meet the smog for the chassis or the engine, whichever is newest or most strict. it's just the hoops you have to jump through in the middle that put a lot of people off.

Rocketwrencher · 09-04-2008, 09:59 PM

Back from practice. Thanks for all the advice and tips, particularly the DMV advice. I have read and printed out almost every post on this site regarding the swap already. I am really looking forward to getting into it and being challenged. The mechanical part of the swap is pretty straight forward, it the electrical that I really have to focus on. I have never completely rewired a truck before. I do have a couple of questions though. When I get the harness, How will I know which plug goes to which injector since I will not be the one removing it? I am planning on putting headers on it to solve the crossover problem, but does that mean I need to run dual exhausts, or do I join the pipes farther back? What about the O2 sensors? one or two? One or two cats? Is the motor heavier than the 3.slow making torsion bar adjustment necessary? I plan on documenting everything that is suggested and putting a link to it like others have on this site. Regarding the battery swap, I am doing it to my 22re and have already fabbed a tray using the stock holddown. There just happens to be an existing nut plate right next to the coolant overflow bottle that the top bracket bolts right up to. Here are some picks of that swap so far. It is made out of .080 321 stainless steel.I also used the origional plastic battery tray to keep the battery out of contact with the metal base. Here are the picks.

**Elvota** · 09-04-2008, 10:19 PM

Best of luck with the swap. A 3.4 for around $300 will really bring the whole project well within reach.

(I moved this thread to the 3.4 swap section)

Rocketwrencher · 09-04-2008, 10:24 PM

Thanks Elvota. I dont know what I was thinking. I guess I was just really excited and wanted to tell someone. By the way, your thread one the swap has given me some valuable insight on this project and I just happened to be reading it right before I found the steal. Thanks for the push.

breknraj · 09-04-2008, 10:31 PM

Once you get it done, you may not want to let your son have it, again! Amongst our various stickied threads, you should be able to gleen 99% of what you'll need to know about the process.

Welcome to the club! I'm certain that you'll love the improvement!

Rocketwrencher · 09-04-2008, 10:38 PM

The only problem is he has wanted this year runner for two years now. We got a pretty good deal on it too; $3000.00. He might be more excited than I am (not). He is a good kid though and I look forward to him and I building it and learning together. Who knows, I might have to buy my own after the 91 is complete....Yea... No, honey, I won't spend any more money.

**Elvota** · 09-04-2008, 10:57 PM

Quote:

Originally Posted by Rocketwrencher

When I get the harness, How will I know which plug goes to which injector since I will not be the one removing it?

You'll need a wiring diagram for the specific model year of your 4Runner as well as the 3.4 donor engine. TIS.com is a great source. Costs $10 a day but you can download and save anything you wish during that time. TIS.com is full of factory wiring diagrams and manuals.

My harness was cut, so in a way I was in the same boat as you. Basically, you'll have to track down the colors for the injectors (as well as other components) and make sure they reach the corresponding pins on the ECM.

Quote:

Originally Posted by Rocketwrencher

I am planning on putting headers on it to solve the crossover problem, but does that mean I need to run dual exhausts, or do I join the pipes farther back?

You wouldn't be able to run duals... plays havoc with the O2 sensors. Well, maybe you can figure it out but most have just joined the exhaust and let the standard O2 sensors do their job.

I installed headers on mine... you can see my crossover in my thread. I do have a SAS, but the process will be vary similar on a IFS truck. Maybe easier, as you don't have to worry about the front DS or axle moving around.

Quote:

Originally Posted by Rocketwrencher

What about the O2 sensors? one or two? One or two cats?

Number of cats and O2 sensors will vary on year and origin of the 3.4. CA motors for example can have more complicated emission systems. I copied JasonD with a fake secondary O2 sensor... Mt. Goat purchased something that was already wired that achieves the same effect.

Quote:

Originally Posted by Rocketwrencher

Is the motor heavier than the 3.slow making torsion bar adjustment necessary?

I think the 3.4 is a bit heaver. I don't have the specs, but I know my front end came down slightly after the install. Not much difference though... maybe a few cranks of your torsion bar if any.

Quote:

Originally Posted by Rocketwrencher

I plan on documenting everything that is suggested and putting a link to it like others have on this site.

Since this thread has been moved to the 3.4 section... and you've already started, I think you'll be good to go from this point.

I don't think you'll find any of us 3.4 swapper regretting the decision. The motor is night and day. I agree with the others though, the only regret you'll have is hearing about the performance upgrade second hand from your son.

mt_goat · 09-05-2008, 04:39 AM

Great job on the battery tray!

mt_goat · 09-05-2008, 04:49 AM

Quote:

Originally Posted by Rocketwrencher

What about the O2 sensors? one or two? One or two cats?

It all depends on the year and model of the ECU you are using. The newer years use A/F sensors.

I"ll bet the smog ref will be going by the year of the ECU too.

RobD · 09-05-2008, 05:04 AM

Quote:

Originally Posted by Rocketwrencher

Back from practice. Thanks for all the advice and tips, particularly the DMV advice. I have read and printed out almost every post on this site regarding the swap already. I am really looking forward to getting into it and being challenged. The mechanical part of the swap is pretty straight forward, it the electrical that I really have to focus on. I have never completely rewired a truck before. I do have a couple of questions though. When I get the harness, How will I know which plug goes to which injector since I will not be the one removing it? I am planning on putting headers on it to solve the crossover problem, but does that mean I need to run dual exhausts, or do I join the pipes farther back? What about the O2 sensors? one or two? One or two cats? Is the motor heavier than the 3.slow making torsion bar adjustment necessary? I plan on documenting everything that is suggested and putting a link to it like others have on this site. Regarding the battery swap, I am doing it to my 22re and have already fabbed a tray using the stock holddown. There just happens to be an existing nut plate right next to the coolant overflow bottle that the top bracket bolts right up to. Here are some picks of that swap so far. It is made out of .080 321 stainless steel.I also used the origional plastic battery tray to keep the battery out of contact with the metal base. Here are the picks.

Let me address the electrical question, since that was my biggest fear. You will NOT be rewiring the truck. Depending on the engine and the condition of the wiring harness (please try to find the computer and harness from the exact same year, if you can), you will be rewiring probably three plugs.

Let me give you the example from mine. The harness came with three plugs intact on the harness ('97 Tacoma, manual transmission, 4x4). All I had to do was plug them into the back of the computer. There was one more socket on the back of the computer, but all it needed was about 8 wires spliced to it, mostly power, switched power, and ground. It didn't have a plug with the computer, so I cut one the same pin count off the old 3.0 harness. No big deal.

There are two body harness plugs under your passenger side of your dashboard. Pull your passenger side kick panel and you'll see your computer. If you pull it out, it will be plugged into the engine harness. Behind that are your two dash plugs. That's what you need to rewire. Your goal will be to create a pin out list for each pin and their function. Say speed sensor is one of them. So, you locate that pin, then you find the same pin on the new 3.4 harness and splice it to the harness (I cut the dash harness off the 3.0 engine side wiring loom and spliced it to the engine loom from the 3.4).

Man, I hope that made sense. But all in all, you're probably swapping about 30 wires, plus hooking up that one plug to provide power to the ECU.

And yeah, good looking battery tray!

RobD · 09-05-2008, 05:10 AM

As for the exhaust, I had a crossover built from the passenger side to the driver side. Make sure it's tight to the bellhousing and close to the block to prevent clearance issues between the frame and firewall.

Then run 2.25" pipe down to a cat and muffler. Mine has two O2 sensors, one ahead and one behind the cat. You won't need to run duals, in fact that's probably a bad idea. The 3.4 isn't a small block Chevy. It needs a little backpressure to help scavange the exhaust gases.

Rocketwrencher · 09-05-2008, 07:36 AM

Thanks for the info RobD. I am leaving shortly to pick up the motor. Will post some picks when I get home this afternoon. Should the motor and harness be from the same year or does that matter? I know the ECU and harness have to be.

mt_goat · 09-05-2008, 07:40 AM

Quote:

Originally Posted by Rocketwrencher

Should the motor and harness be from the same year or does that matter? I know the ECU and harness have to be.

I would sure try to get it the same, there may have been a change in plugs and wiring for sensors, injectors, etc...

RobD · 09-05-2008, 09:10 PM

Quote:

Originally Posted by mt_goat

I would sure try to get it the same, there may have been a change in plugs and wiring for sensors, injectors, etc...

x3

It's conceivable you could do it with different harnesses/ECUs, but man...you're way ahead of the game. I got lucky with the 97, because it was intact and I could use one of the plugs from my 3.0 harness for its power plug. I've seen other years and they use some different styles.

09-04-2008, 06:11 PM	#1 (permalink)
Rocketwrencher Registered User Join Date: Jul 2008 Location: Temecula, CA Posts: 136	Jumping in to the 3.0/3.4 swap I am in the middle of rebuilding my 91 22re truck motor and my 16 year old comes home last week and says the CEL is on in his 95 3.slow 4-runner. So I check it out and sure enough, chocolate milk. The motor has 157000 miles on it and we are the second owners of the truck so I thought I would give the dealer recall a try. No such luck. The origional owner had it done in '91 and the dealer said they will only replace it once. So I started checking around for rebuilds versus rebuilding it myself and I came across a guy selling a 3.4 out of a rolled Taco with 90,000 miles on it and he is only asking $300.00. I just about s**t my pants! I called immediately and suprisingly enough, he still had it.www.offroadsolutions.com/products/ I pick it up tomorrow, That is if he doesn't sell it under my nose or read any of the articles on this site before then. He doesn't have the wiring harness for it, so will have to scavenge a junkyard truck for that. My son is pretty excited. We plan on rebuilding the motor before we drop it in just because I don't know what the motor has been through, but at that price, I think it is the smart thing to do. Any ideas or thoughts from those who have been there? By the way, we live in the liberal state of CA, so will have to put up with the smog regs. Here is a pick of the motor that will soon be replaced....I hope. I have to go to football practice now but will be back online tonight at nine if anybody has any thoughts or suggestions.

09-04-2008, 06:43 PM	#4 (permalink)
mt_goat Contributing Member Join Date: Nov 2002 Location: Oklahoma State Posts: 7,425	Here's a section full of reading for you: http://www.yotatech.com/f160/ __________________ Dale "America is in a hole and it's getting deeper every day. We import 70% of our oil at a cost of $700 billion a year - four times the annual cost of the Iraq war." T. Boone Pickens Check out the plan: http://www.pickensplan.com/index.php and http://www.cngnow.com/EN-US/Pages/default.aspx

09-04-2008, 09:10 PM	#5 (permalink)
RobD Registered User Join Date: Jun 2006 Location: Calgary, AB Posts: 1,068	Plus this: http://www.andrewzook.com/content/view/22/48/ You'll need to save the oil pan, pickup and dipstick tube from the 3.0 and swap them into the 3.4. Don't cut the alternator harness, just tuck it up away. You're going to need to move the battery over and have an exhaust crossover fabbed or do it yourself. The wiring isn't that tough, once you know what the end goal is. Feel free to ask questions. Mt_goat, Elvota, me, and a bunch of others have done the swap. Mechanically, it isn't hard. Even the electrical isn't too bad. And they're a lot of fun to drive, once they're done. __________________ 1991 4Runner, 3.4 5VZFE swap, OME shocks/springs, 33" BFG All Terrain T/A KOs, Pioneer head unit, Infinity speakers, XM Satellite radio

09-04-2008, 10:19 PM	#8 (permalink)
Elvota Super Moderator Staff Join Date: Jun 2005 Location: Phx, AZ Posts: 3,442	Best of luck with the swap. A 3.4 for around $300 will really bring the whole project well within reach. (I moved this thread to the 3.4 swap section) __________________ ================ 1990 4Runner \| V6 3.4 \| 5spd \| 240 someoddthousand miles \| SR5 \| SAS \| RLS \| 35's \| ARB \| TJM \| 217 to 1 \| W8000 - four wheels \| three sticks \| two hands \| one trail - RIGITY DIGITY

09-04-2008, 10:31 PM	#10 (permalink)
breknraj Contributing Member Join Date: Jan 2006 Location: Summit County, Colorado Posts: 862	Once you get it done, you may not want to let your son have it, again! Amongst our various stickied threads, you should be able to gleen 99% of what you'll need to know about the process. Welcome to the club! I'm certain that you'll love the improvement! __________________ Raj : 1960 Homo Sapien. 192cm, Blonde, Blue. Soon to lose spare tire. Worf : 1990 SR5 Xtracab 4x4 5 speed, Inca Red Metallic. 3.4 converted, with Taco 5 spoke alloys, 275/65R16 BFG AT K/Os. Soon to add rear e-locker.

09-04-2008, 06:14 PM	#2 (permalink)
Rocketwrencher Registered User Join Date: Jul 2008 Location: Temecula, CA Posts: 136	By the way, If I am able to get the motor, This 3.0 is for sale whole or parts except for the items that I need for the swap. Let me know if you need any thing.

09-04-2008, 06:42 PM	#3 (permalink)
3yotys Registered User Join Date: Dec 2004 Location: Taylorshole,Mississippi Posts: 718	Man GO for it!It will 5 &10 you till broke but it's worth it.Take that 3.0 to the scrap yard. Bigblock

09-04-2008, 09:59 PM	#7 (permalink)
Rocketwrencher Registered User Join Date: Jul 2008 Location: Temecula, CA Posts: 136	Back from practice. Thanks for all the advice and tips, particularly the DMV advice. I have read and printed out almost every post on this site regarding the swap already. I am really looking forward to getting into it and being challenged. The mechanical part of the swap is pretty straight forward, it the electrical that I really have to focus on. I have never completely rewired a truck before. I do have a couple of questions though. When I get the harness, How will I know which plug goes to which injector since I will not be the one removing it? I am planning on putting headers on it to solve the crossover problem, but does that mean I need to run dual exhausts, or do I join the pipes farther back? What about the O2 sensors? one or two? One or two cats? Is the motor heavier than the 3.slow making torsion bar adjustment necessary? I plan on documenting everything that is suggested and putting a link to it like others have on this site. Regarding the battery swap, I am doing it to my 22re and have already fabbed a tray using the stock holddown. There just happens to be an existing nut plate right next to the coolant overflow bottle that the top bracket bolts right up to. Here are some picks of that swap so far. It is made out of .080 321 stainless steel.I also used the origional plastic battery tray to keep the battery out of contact with the metal base. Here are the picks.

09-04-2008, 10:24 PM	#9 (permalink)
Rocketwrencher Registered User Join Date: Jul 2008 Location: Temecula, CA Posts: 136	Thanks Elvota. I dont know what I was thinking. I guess I was just really excited and wanted to tell someone. By the way, your thread one the swap has given me some valuable insight on this project and I just happened to be reading it right before I found the steal. Thanks for the push.

09-04-2008, 10:38 PM	#11 (permalink)
Rocketwrencher Registered User Join Date: Jul 2008 Location: Temecula, CA Posts: 136	The only problem is he has wanted this year runner for two years now. We got a pretty good deal on it too; $3000.00. He might be more excited than I am (not). He is a good kid though and I look forward to him and I building it and learning together. Who knows, I might have to buy my own after the 91 is complete....Yea... No, honey, I won't spend any more money.

09-05-2008, 04:39 AM	#13 (permalink)
mt_goat Contributing Member Join Date: Nov 2002 Location: Oklahoma State Posts: 7,425	Great job on the battery tray! __________________ Dale "America is in a hole and it's getting deeper every day. We import 70% of our oil at a cost of $700 billion a year - four times the annual cost of the Iraq war." T. Boone Pickens Check out the plan: http://www.pickensplan.com/index.php and http://www.cngnow.com/EN-US/Pages/default.aspx

09-05-2008, 05:10 AM	#16 (permalink)
RobD Registered User Join Date: Jun 2006 Location: Calgary, AB Posts: 1,068	As for the exhaust, I had a crossover built from the passenger side to the driver side. Make sure it's tight to the bellhousing and close to the block to prevent clearance issues between the frame and firewall. Then run 2.25" pipe down to a cat and muffler. Mine has two O2 sensors, one ahead and one behind the cat. You won't need to run duals, in fact that's probably a bad idea. The 3.4 isn't a small block Chevy. It needs a little backpressure to help scavange the exhaust gases. __________________ 1991 4Runner, 3.4 5VZFE swap, OME shocks/springs, 33" BFG All Terrain T/A KOs, Pioneer head unit, Infinity speakers, XM Satellite radio

09-05-2008, 07:36 AM	#17 (permalink)
Rocketwrencher Registered User Join Date: Jul 2008 Location: Temecula, CA Posts: 136	Thanks for the info RobD. I am leaving shortly to pick up the motor. Will post some picks when I get home this afternoon. Should the motor and harness be from the same year or does that matter? I know the ECU and harness have to be.