3.0L to 3.4L Swap QuestionS
Jan 29, 2005 | 01:22 PM
#1
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From: Alaska
3.0L to 3.4L Swap QuestionS
I have a few NOOB questions to ask so forgive me, please. All the data seems to not be too current on the web regarding this swap. (IE from two years or more) . I have a 1991 4runner that has the 3.slo in it, and was considering doing a rebuild but decided not to. So I am gonna do a swap to a 3.4L, but can't spend a whole lot, so I need info on what particulars to look out for. I understand that I need to get the ECM from the donor, but I have other questions too.
1. Wiring, wiring, wiring, what do I need to know? I understand I need to get the TWD for my particular truck, and for the eng I am gonna swap in, but is there anything else? I read in one place that you need the original engine compartment harness from the donor vehicle. Will I also need the under dash harness? Also can the TWD's be found on the net anywhere??? They have gotta be out there somewhere...
2. What mods if any need to be done to the tranny?(New bellhousing, new clutch slave cylinder, or is it fine the way it is?) Do I need a different flywheel? Which clutch to use 3.0 or 3.4??
3. Exhaust, I read that this is the most difficult part of the mod. If so why is it, would it be better to take it to a custom exhaust shop? Would I be able to swap in the exhaust from the donor vehicle? Do I need both the O2 sensors, or is 1 okay?
4. 3.4L with the supercharger? Is there any model Toyota released that came with this as a factory option? If so which one is it? What VIN code should I look for? The local junk yard has about 20 or so 3.4L's in stock. All have pretty good compression, and oil pressure readings. Is there a particular year I should really look for or all they all the same?(IE computer compatibility, what year computer with what year engine??? or are they all compatible?)
Lemme say thanks in advance to anyone who takes the time to read this, and then respond. I know it is alot of questions, but I wanna get it right without too many surprises.
1. Wiring, wiring, wiring, what do I need to know? I understand I need to get the TWD for my particular truck, and for the eng I am gonna swap in, but is there anything else? I read in one place that you need the original engine compartment harness from the donor vehicle. Will I also need the under dash harness? Also can the TWD's be found on the net anywhere??? They have gotta be out there somewhere...
2. What mods if any need to be done to the tranny?(New bellhousing, new clutch slave cylinder, or is it fine the way it is?) Do I need a different flywheel? Which clutch to use 3.0 or 3.4??
3. Exhaust, I read that this is the most difficult part of the mod. If so why is it, would it be better to take it to a custom exhaust shop? Would I be able to swap in the exhaust from the donor vehicle? Do I need both the O2 sensors, or is 1 okay?
4. 3.4L with the supercharger? Is there any model Toyota released that came with this as a factory option? If so which one is it? What VIN code should I look for? The local junk yard has about 20 or so 3.4L's in stock. All have pretty good compression, and oil pressure readings. Is there a particular year I should really look for or all they all the same?(IE computer compatibility, what year computer with what year engine??? or are they all compatible?)
Lemme say thanks in advance to anyone who takes the time to read this, and then respond. I know it is alot of questions, but I wanna get it right without too many surprises.
Last edited by Kyuss; Feb 12, 2005 at 05:26 PM.
Jan 29, 2005 | 03:34 PM
#2
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Joined: Jul 2003
Posts: 8,807
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From: Montreal, QC Canada
Originally Posted by Kyuss
I have a few NOOB questions to ask so forgive me, please. All the data seems to not be too current on the web regarding this swap. (IE from two years or more) . I have a 1991 4runner that has the 3.slo in it, and was considering doing a rebuild until I learned Toyota isn't making it anymore. So I am gonna do a swap to a 3.4L, but can't spend a whole lot, so I need info on what particulars to look out for. I understand that I need to get the ECM from the donor, but I have other questions too.
1. Wiring, wiring, wiring, what do I need to know? I understand I need to get the TWD for my particular truck, and for the eng I am gonna swap in, but is there anything else? I read in one place that you need the original engine compartment harness from the donor vehicle. Will I also need the under dash harness? Also can the TWD's be found on the net anywhere??? They have gotta be out there somewhere...
2. What mods if any need to be done to the tranny?(New bellhousing, new clutch slave cylinder, or is it fine the way it is?) Do I need a different flywheel? Which clutch to use 3.0 or 3.4??
3. Exhaust, I read that this is the most difficult part of the mod. If so why is it, would it be better to take it to a custom exhaust shop? Would I be able to swap in the exhaust from the donor vehicle? Do I need both the O2 sensors, or is 1 okay?
4. 3.4L with the supercharger? Is there any model Toyota released that came with this as a factory option? If so which one is it? What VIN code should I look for? The local junk yard has about 20 or so 3.4L's in stock. All have pretty good compression, and oil pressure readings. Is there a particular year I should really look for or all they all the same?(IE computer compatibility, what year computer with what year engine??? or are they all compatible?)
Lemme say thanks in advance to anyone who takes the time to read this, and then respond. I know it is alot of questions, but I wanna get it right without too many surprises.
1. Wiring, wiring, wiring, what do I need to know? I understand I need to get the TWD for my particular truck, and for the eng I am gonna swap in, but is there anything else? I read in one place that you need the original engine compartment harness from the donor vehicle. Will I also need the under dash harness? Also can the TWD's be found on the net anywhere??? They have gotta be out there somewhere...
2. What mods if any need to be done to the tranny?(New bellhousing, new clutch slave cylinder, or is it fine the way it is?) Do I need a different flywheel? Which clutch to use 3.0 or 3.4??
3. Exhaust, I read that this is the most difficult part of the mod. If so why is it, would it be better to take it to a custom exhaust shop? Would I be able to swap in the exhaust from the donor vehicle? Do I need both the O2 sensors, or is 1 okay?
4. 3.4L with the supercharger? Is there any model Toyota released that came with this as a factory option? If so which one is it? What VIN code should I look for? The local junk yard has about 20 or so 3.4L's in stock. All have pretty good compression, and oil pressure readings. Is there a particular year I should really look for or all they all the same?(IE computer compatibility, what year computer with what year engine??? or are they all compatible?)
Lemme say thanks in advance to anyone who takes the time to read this, and then respond. I know it is alot of questions, but I wanna get it right without too many surprises.
This is one of the best threads out there covering the topic:
http://www.pirate4x4.com/forum/showt...5&pagenumber=1
Very long thread but this should cover almost everything:
http://www.4x4wire.com/forums/showfl...=&fpart=1&vc=1
Another thread:
http://www.4x4wire.com/forums/showfl...5&o=14&fpart=1
Some pics for you (and thread that goes with it):
http://www.picturetrail.com/gallery/...1342799&PATHID
http://www.automotivetalk.net/showmessages.php?id=633
Lots of reading here for ya.
Feb 1, 2005 | 01:44 PM
#4
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From: Alaska
3.0l to 3.4l conversion wiring question.
Ok sourced my eng and computer, now begins the fun part! What wire goes where? 
Is there a simplified wiring diagram available, other than Toys techinfo site? I am an aircraft mechanic, but these toys seem to keep it as confusing as possible.(And I thought F-15's were bad!) Any help anyone can offer is GREATLY appreciated, I can handle the splicing, but the lining up of the harness with the wires, is really confusing me. 
Thanks
BTW I can't afford to go with ORS wiring harness, so please don't suggest it
Is there a simplified wiring diagram available, other than Toys techinfo site? I am an aircraft mechanic, but these toys seem to keep it as confusing as possible.(And I thought F-15's were bad!) Any help anyone can offer is GREATLY appreciated, I can handle the splicing, but the lining up of the harness with the wires, is really confusing me. ThanksBTW I can't afford to go with ORS wiring harness, so please don't suggest it
Feb 1, 2005 | 08:50 PM
#7
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Joined: Jan 2004
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didi you get the engine harness from the donor? the guy on 4x4wire-co93runner basically rewired it all himself and would be the one to talk with. he is very helpful and doesn't mind helping. I would suggest getting in contact with him for some additional info. he basically made a full size version of the wire diagrams and then laid the harness out beside it going thru it one by one. took him quite a few hours but he gained a ton in experience.
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Feb 5, 2005 | 08:11 PM
#10
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Joined: Sep 2003
Posts: 81
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From: Santa Cruz, CA
I highly recommend getting the engine wiring harness. From there it's not too bad. Go to http://techinfo.toyota.com/ and join for a day or two and download the entire EWD for both vehicles. Far cheaper than buying the hard copy and will include everything you need. Print them out and stick them in a binder. I made a sheet that shows what to what for a 90 4Runner with a 97 3.4, but that is not likely the same as other years.
Feb 7, 2005 | 05:11 PM
#11
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Joined: May 2004
Posts: 336
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From: Lusby, MD
rather than starting a new thread but the headers...
Say If I get a set of Downey Headers with a crossover... can I use that? or do you have to go out and get a custom crossover built.
Other than that I think I am ready for my summer project... now its time to start gatherign parts...
Say If I get a set of Downey Headers with a crossover... can I use that? or do you have to go out and get a custom crossover built.
Other than that I think I am ready for my summer project... now its time to start gatherign parts...
Feb 12, 2005 | 12:08 AM
#12
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From: Alaska
Progress report;
I have the motor installed, and did'nt even have to change the motor mounts or the oil pan! I was amazed that the oil pan was identical to the 3.0's. So on a whim I thought maybe the motor mounts were the same. So I diced it and it came out in my favor. The only thing I had to change to physically accomidate the motor was the stiffener plate on the left hand side. The starter was a little hard to get in, but I shoe-horned it in. Then fumbled around with it for about an hour getting it positioned right. Now I am tackling the wiring. Jeesh, maybe I am stoopid, but I can't seem to grasp the logic that the Toy engineers used Hopefully after I sleep on it for a bit, maybe divine inspiration will hit me. 
CoRunner from 4x4wire hooked me up with abunch of notes and stuff.
I really appreciated his efforts on getting me that stuff,
Although I think when I started downloading the EWD's from Toyota.techinfo.com, I might have missed one, but I did get a bunch off good stuf from there though.
The crossover had to come out, so I was wondering if anyone has tried reusing it, just cutting the flanges off, and welding them onto their opposite sides. Just a thought I had...
Well back to the garage, wish me luck.
BTW does anyone happen to have the wiring diagram for a 1991 runner AC/EFI system?????(It's the only one I missed, I think...
)
yeah I am rambling but I am tired and seeing crosseyed
I have the motor installed, and did'nt even have to change the motor mounts or the oil pan! I was amazed that the oil pan was identical to the 3.0's. So on a whim I thought maybe the motor mounts were the same. So I diced it and it came out in my favor. The only thing I had to change to physically accomidate the motor was the stiffener plate on the left hand side. The starter was a little hard to get in, but I shoe-horned it in. Then fumbled around with it for about an hour getting it positioned right. Now I am tackling the wiring. Jeesh, maybe I am stoopid, but I can't seem to grasp the logic that the Toy engineers used
Hopefully after I sleep on it for a bit, maybe divine inspiration will hit me. CoRunner from 4x4wire hooked me up with abunch of notes and stuff.
I really appreciated his efforts on getting me that stuff, Although I think when I started downloading the EWD's from Toyota.techinfo.com, I might have missed one, but I did get a bunch off good stuf from there though.
The crossover had to come out, so I was wondering if anyone has tried reusing it, just cutting the flanges off, and welding them onto their opposite sides. Just a thought I had...
Well back to the garage, wish me luck.
BTW does anyone happen to have the wiring diagram for a 1991 runner AC/EFI system?????(It's the only one I missed, I think...
)yeah I am rambling but I am tired and seeing crosseyed
Last edited by Kyuss; Feb 12, 2005 at 12:12 AM.
Feb 12, 2005 | 03:42 AM
#13
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Joined: Jul 2003
Posts: 8,807
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From: Montreal, QC Canada
It might be nice if you could create a wiring diagram for when you get it all working and we can post it here. That way it will be documented for others who want to do the same thing. Glad to hear it went so well thus far!
Feb 15, 2005 | 09:54 AM
#17
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Joined: Sep 2002
Posts: 4,216
Likes: 1
From: Fort Collins, CO
Engine swaps done on a budget are really like smart blondes. Darn near impossible to find.
I have a 3.4 in my 95 and love it.
There have been at least two threads in the last week about this sort of thing.
I have a 3.4 in my 95 and love it.
There have been at least two threads in the last week about this sort of thing.
Feb 23, 2005 | 10:55 AM
#19
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Joined: Jan 2005
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From: Alaska
Quick update;
The Beast LIVES!!!
Just took it to the shop for custom exhaust, it wouldn't start at first, so I primed the system before cranking it again, and VOILA, it ran first time, and no CEL! Woo Hoo, I am so stoked, can't wait til a lil more moolah runs in, so I can get the SC. I have some docs I'll post up here as soon as I get them off the laptop. It'll contain all the pin locations for both the 3vz and the 5vz, including where to put the 5vz pins. It will only be specific to the 91 4runner, and the 96 T100 3.4L. BTW through much PITA and agony I discovered that I had a 96 T100 motor, woulda been nice had the junkyard told me the right motor in the 1st place, only set me back by about 4 hours...peace out I am gonna play some BF:V finally!
The Beast LIVES!!!
Just took it to the shop for custom exhaust, it wouldn't start at first, so I primed the system before cranking it again, and VOILA, it ran first time, and no CEL!
Woo Hoo, I am so stoked, can't wait til a lil more moolah runs in, so I can get the SC. I have some docs I'll post up here as soon as I get them off the laptop. It'll contain all the pin locations for both the 3vz and the 5vz, including where to put the 5vz pins. It will only be specific to the 91 4runner, and the 96 T100 3.4L. BTW through much PITA and agony I discovered that I had a 96 T100 motor, woulda been nice had the junkyard told me the right motor in the 1st place, only set me back by about 4 hours...peace out I am gonna play some BF:V finally!
