towotaguy

So I have learned that the group of people on this forum are full of amazing knowledge and I'm very thankful for everyones help with little questions I've had in the past.

I'm about to start my swap and i will do my best to keep this thread updated so maybe i can help someone in the future and I'm sure I'm going to run into a few speed bumps along the way. so to start off i have an 89 sr5 pickup that ill be putting a 96 3.4 into. so here are the things i got from the donor truck

-engine
-body harness and ecu
-exhaust with both o2 sensors
-fly wheel and clutch
-starter

I still needed a few things and I'm extremely limited in supplies and time due to the fact that I'm in rural Alaska so i chose to order from ORS. i placed my order last week and I'm about 5 weeks out from receiving everything.

-sump kit
-battery tray
-exhaust crossover pipe
-conversion harness
-hose kit

i am completely open to comments and like i said ill do my best to post as i go.

towotaguy

So in regards to the wire harness, does the dash need to come out or will pulling it out just make life easier? I want to change my heater core if the dash just has to come out but if not then the old one is staying put.

SacRunner

I assume you're talking about the 89's dash, but no, you don't need to pull the dash.

You will need to pull the gauge cluster to remove the tachometer to solder in the 10K ohm resistor to keep the tach accurate with the newer ignitor, but that's been well documented, and there should be lots pictures for the various years.

towotaguy

Yeah I knew the cluster had to come out but I didn't see anything about the whole dash so just thought I'd ask. I believe my 3.0 threw in the towel today at 277519. There has been an issue with one of the heads and when I parked it last night coolant was pouring out in a steady stream. I couldn't have picked a better time to do the swap.

wolfrunner

Its funny I think mine also knew that I was up to something cause it started burning oil like never before! Good luck with your swap!

towotaguy

Today i was finally able to start the swap. Ive gotten the transmission out and the old 3.0 and I'm going to try and clean things up under the hood before adding the new goodies. i was curious about the O2 sensors. Has anyone deleted them without freaking out the emissions system?

thefinn2003

you don't want to delete your o2 sensors. the engine won't run right. it won't start for ˟˟˟˟. your fuel economy will suck. power will suffer badly. o2 sensors are your friends. do not under any circumstances attempt to run an engine designed to use o2 sensors without them. the ecu map NEEDS o2 sensors. I can't stress this enough. do yourself a favor and buy the flanges (available from a couple vendors) and put the factory o2 sensors into the system like they're supposed to be.

I did a 3.0 - 3.4 swap a couple years ago. there are two types of 3.4 ecu's when it comes to o2 sensors. the early 3.4 used a single sensor after the cat. the late model 3.4 had two cats with a sensor after each one. build your exhaust system to match the factory spec. do not attempt to save money and deviate from the factory spec or you will screw things up big time. just don't.

ian.

thefinn2003

you don't want to delete your o2 sensors. the engine won't run right. it won't start for ˟˟˟˟. your fuel economy will suck. power will suffer badly. o2 sensors are your friends. do not under any circumstances attempt to run an engine designed to use o2 sensors without them. the ecu map NEEDS o2 sensors. I can't stress this enough. do yourself a favor and buy the flanges (available from a couple vendors) and put the factory o2 sensors into the system like they're supposed to be.

I did a 3.0 - 3.4 swap a couple years ago. there are two types of 3.4 ecu's when it comes to o2 sensors. the early 3.4 used a single sensor after the cat. the late model 3.4 had two cats with a sensor after each one. build your exhaust system to match the factory spec. do not attempt to save money and deviate from the factory spec or you will screw things up big time. just don't.

ian.

thefinn2003

incidentally, i bought the conversion harness from ors and it worked great. except that i didn't like the length of various legs or how things were routed, so i ended up lengthening or shortening just about every lead in the harness. i also had a fsm for my model year truck and one for the donor, so i had everything i needed to do it myself anyway.

long story short, if you have a basic understanding of automotive dc power, you can pretty much do the wiring yourself without the conversion harness. to my mind, the number one reason to go with ors is that he supplies you with all the right connectors. if i were to do it again, i would do i myself from scratch, but if you don't have a good feel for a chassis ground dc system, some soldering skill, and a supply of heat-shrink insulation, i would buy the harness (don't try this if you don't know, or are unwilling to learn how to properly do wiring - it's a valuable skill, but don't mess around with it - bad wiring will burn your **** to the ground).

everything else is pretty easy. if you can weld, get yourself some steel angle and you can put together a good battery tray. get some rubber bushings, standoffs, etc from the hardware store to mount the 3.4 factory airbox on the passenger side. buy the power steering hoses from ors and route them in the factory location underneath the radiator fan. i built a custom bridge across the frame rails with some more steel angle, similar to the 3.0 setup. also get the ors hp fuel line. he's got a lot of stuff that makes life a lot easier, for not much more than you'd pay otherwise.

i've heard various reports regarding how the fan aligns with the radiator shroud. some people say the stock shroud is fine. others say it interferes. i ended up with an aftermarket aluminum radiator that doesn't remotely match the shroud, so i just left it off. haven't had a problem with overheating, so i haven't done anything about it. if you live in a hot location, this may be an issue. regardless, make sure the fan doesn't rub on your power steering lines.

make sure you have the right combination of clutch components. and make sure you document what you've done, or the next time you go to do a clutch you might buy the wrong pilot bearing. then you'll have to pull the tranny again to try to figure out what's wrong.

one tricky part of this swap is the evap. i recommend using the COMPLETE evap system from a 3.4 donor, including vsv valves. i used the stock 3.0 evap system. as i understand it, the vsv's used on the 3.0 are switching valves, while those for the 3.4 are modulating valves. it seems that the 3.4 ecu expects to control modulating valves, so at low manifold pressure the ecu attempts to only partially open one of the vsv's. if this is a 3.0 vsv, it will see a voltage from the ecu that is somewhere between its open and closed state, so apparently the valve cycles rapidly between open and closed. this is a little disconcerting cuz it happens when i'm sitting at a stop light: the valve is mounted in the engine bay on the wheel well panel, so the noise carries quite a bit, and it sounds a lot like lifter noise. cycling like this will probably contribute to the premature failure of the valve, and thus of the evap system as a whole. i plan to eventually swap out for a complete 3.4 evap system.

whether it's the 3.0 system or the 3.4, do it as documented elsewhere. you don't want your tank blowing out. evap might be the number one cause of check engine lights in this swap (i've seen two other swaps which threw evap codes).

of course you might need to chase some other problems with the donor motor. i ended up replacing all the injectors and the mass air sensor.

the most time-consuming part for me was the exhaust system, since i wanted to route it as tight as i could up inside the frame. and i don't like where the ors crossover dumps to the downpipe. the crossover is right where the driver's side torsion bar rides above the frame rail, and very near the brake line. in my case, i had to remove the heat shield in that location to make room for the exhaust flange. this makes fabricating the exhaust there a bit tricky. imo, the crossover is a poor design and should turn a few degrees more, and/or extend further down along the bell housing. the inside flange bolt is a really tight fit. but there isn't really another option unless you want to do your own crossover.

if you can't build your own exhaust, take it to a GOOD exhaust shop, or they will f*** it up, guaranteed.

do not skimp on any part of this swap. a substandard installation will defeat the purpose of replacing the 3.0 (which is actually a solid motor, albeit asthmatic).

ian.

thefinn2003

correction: the late 3.4 used two o2 sensors, one BEFORE each cat. the fsm will use different terminology and different part numbers for them, but i think they're actually identical. the first one does what an o2 sensor is supposed to do: adjust the fuel map according to exhaust content (this is absolutely critical in an obd2 engine - do not omit this sensor). the second one (i believe) just checks the functioning of the first catalytic converter. if this sensor is absent, and the ecu expects to see it, the system will throw an error code. not really a big deal, but you really want the CEL to indicate a real problem. that's why we have obd2: the CEL is also your friend. unless you're an engine-whisperer, it'll tell you all kinds of things about your motor that you wouldn't otherwise know about. also, do yourself a favor and get a code reader, and familiarize yourself with all the various errors. i use an obdlink. it talks to your smartphone via bluetooth or wireless.

whatever you do, make sure you have the sensor arrangement that matches your ecu (e.g. you could potentially have a late motor with an early ecu, in which case you'd only need the one o2 sensor). and to be safe, get the correct sensor that's supposed to be in that location. electronics can be finicky.

ian.

towotaguy

this is a prime example of why I'm posting my progress along the way. i was able to get all of my 3.4 parts from the same truck so the ecu matches the engine year (1996). i don't have access to a welder or the proper tools to do the exhaust myself however i did purchase a crossover pipe from ors. i was going to get everything installed then trailer the truck to an exhaust shop near by and let them run the exhaust. i just have to make sure they do not start the truck at all until the job is complete and even then ill probably need to do some tweaking before its road worthy. so i don't plan on trying to reuse an old cat but i only removed one cat from the donor truck, is there supposed to be two?

thefinn2003

a 96 uses a single cat, single o2 sensor (after the cat i assume). personally i don't like using old parts if i don't have to. my swap ended up costing me about $3k. complete motor with accessories was $800, harness and stuff from ors was close to $1k, but i ended up replacing so much stuff, i easily spent another $1k in miscellaneous parts. whenever i didn't like the look of something i'd throw it in the spares pile and buy a new one.

i absolutely recommend replacing anything you see that you think is questionable, especially on a motor that old. i'd certainly get a new o2 sensor (new bosche from rockauto = $50). and a cat should be only $100 or so.

ian.

SacRunner

FYI, a 96 4Runner (Tacoma/T100 may be different) uses 2 O2 sensors, 1 before and 1 after the cat.

From the 96 4Runner EWD (I circled the 2 O2 sensors in yellow):


And FWIW, I completely agree with everything else you're saying, all great tips.

69sixpackbee

The post '99 vehicles used AFR sensors (wide band O2), pre-cat. I used a 2000 engine and harness but repinned it to use a '98 ECU. Rewired it for the earlier O2. Cheaper and it runs fine.

Bud

towotaguy

So today i finished the easy part. The 3.4 is now in and mated to the transmission. I had some trouble getting the engine mounts to line up then i saw that one of them on the 3.4 was broken. Luckily the 3.0 engine mounts were the same so that wasn't to much of a set back. The 3.4 that I'm using was taken out of a totaled truck so i guess the mount broke in the accident.

The hurtle i face now is routing a new exhaust and installing the conversion harness i got from ORS. So far everything I've purchased from them has worked with no minor tweaking needed. I used the clutch and flywheel from the 3.0 because the one from the 3.4 was pretty rough and the 3.0 components worked like a charm. So here are some pics of everything so far. First should be a plug that is now where the old dip stick was then the new dipstick also from ORS, then the crossover pipe and flywheel/clutch, and last the new power steering line. i got lucky and was able to reuse the high pressure fittings so i just shortened the old hose and attached the 3.4 spout. I seem to remember hearing about a website where i could pay a fee and download pages of service manuals. Dose such a site exist?

thefinn2003

what pages in particular are you looking for? i have an 88, an 89, and an 02 manual.

towotaguy

I need information on the 3.4 vacuum line routing. I'm using the canister from the 3.0 rather then the 3.4. I just need to know which lines can be a eliminated from the 3.4. I would have had the truck finished today but welding and routing the new exhaust took longer then I had planed for.

thefinn2003

https://www.yotatech.com/forums/f160...85/index4.html

towotaguy

Today i got all the EVAP stuff worked out and the last of the wiring done and it runs beautifully. I still have some cleaning up to do but i will post the pics of the finished product soon and details of problems i came across and how i solved them.

I am stumped on the front diff. its vacuum operated and I'm curious as to know if i can just tee into some similar lines or if they need to be ran through some sensor. If anyone has some input on this issue it would be much appreciated.

vasinvictor

iTrader: (3)

There are two vacuum lines going to the ADD. One to lock, and one to unlock. In a pinch, you can just hook the "lock" vacuum line to a vacuum tee behind the throttle body. To do it right, you need a the ADD VSV and wire it up to your transfer case lever wire.

Many of use those to full time lock the front ADD (there are a couple ways to do it, including the vacuum line I just told you about) and get manual locking hubs.