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Just joined but have been reading for a bit. I am in the process of doing a 3.4 swap into my 89 manual 3.0 4runner. I have pulled the 3.4 out of a 97 auto 4runner. I bought an ECU from a 99 tacoma. The plugs are the same on both the 3.4 ECU's but obviously not the wiring. I'm really questioning my sanity right now. I bought this 4runner with a bent frame, spliced and repaired that. The front of the frame is from a 4cyl auto. Since I'm doing a SAS too I just cut the motor mounts and all the suspension brackets. I bought all the EWD's for the 97 and 99. I also went to the dealer and took pictures of the 88 EWD's. Both the motors were leaking oil from all over! I have replaced the timing belt, water pump, front crank seal, cam seals, valve cover gaskets and cleaned all the oil/dirt that I could. Switched oil pans, baffle and sump with the 3.0.
A few questions I have are:
1- The fuel line off the frame and motor are female, is there an adapter I can get so that I don't need to buy a new fuel line from ORS?
2- Should I go buy a new radiator? The one I have now has a dog leg on the top orfice, I am thinking about taking it to a radiator shop and having them turn it or put a straight piece on it....thoughts?
Second, ditch that 99 ECU and spend some time on car-part.com (or your local junk yards) to find a 96-97 4Runner M/T ECU; 2wd vs 4wd is almost a non-issue. The difference in electronics (both in terms of the 97 vs 99 version and also in terms of some sensors the 99 will be expecting aren't present on the 97). You can make the 99 ECU work with your 97 motor + harness, but you'll be paying lots more to replace parts (MAF and throttle body for example) just to match an ECU that you may have gotten a good deal on.
1. I can't really help with the fuel line issue on a first gen, but on my 91, I simply un-bolted my 3.0 "soft-line" from the hard line on the frame, then rotated the 3.4's fuel line 180* and it bolted right up to the factory hard line, no adapter needed (but again, this was a second gen).
2. If your current radiator is the copper/brass type and it holds coolant, keep it and find hoses that work. I reused my 3.0's for 2-3 years with that 45* dog leg on the top inlet (I think) but the top radiator hose recently started oozing coolant, so I pulled it, took it to a local radiator shop, they rodded it out (removed the top and bottom tanks, ran a rod through the vanes to clean out any debris, the re-braze everything back together) and I had them install a new straight inlet ($135 out the door, 125 for the cleaning and 10 for the new inlet).
You're obviously in the right spot, but I do suggest reading through some of the older, similar swaps, and some of the others that are "stickied" at the top to get a better idea of what to expect.
Are you in CA and needing this to pass SMOG? If so, that can open another can of worms, but it's manageable if you stay on top of the "rules" from the start.
Thanks for a great reply! I will look into an older ECU. I did give the part numbers for the harness and ECU to toyswaponly and they told me it will work with a MAF from a 99. Are you sure about the throttle body? How do you guys know all this stuff?! I have been reading a lot on how to do this. I've already rotated my fuel line 180°. I think I will just buy the extension or full hose from ORS because female to female won't work and I still think it will be too short. The radiator is has no plastic so I might just take it t a radiator shop and have them do what you did. I'm trying to do this on the cheap yet do it right. Again thanks for the reply and I'm curious about your response on the throttle body. If I need another ECU then so be it. I have plenty of other things to work on like the suspension, interior, locate at least one leak into the cab, motor mounts, brakes, EVAP, intake....and I'm sure more.
Last edited by potatohead; 11-02-2015 at 10:08 PM.
The throttle body issue is with the Throttle Position Sensor (TPS), I seem to remember reading about Toyota switchich from a three wire to a four wire TPS, but I don't remember when they made that change.
So I stopped to pick up some parts at the Toyota dealer today. The part number for the TPS is the same on my engine and the 99 that my ECU came from so I think I'm good to go! The parts I picked up should allow me to seal up my motor and drop it between the rails. Then I have to build motor mounts. Will grab some pics this weekend because must like pics.
So I have made frame mounts for the motor and the motor is in now. I'm a little overwhelmed by the wiring. I have the diagrams. I have the donor vehicle. I have to re-pin my engine harness for the MT ECU. Then I need to figure out how the body harness and the ECU go together....? (I think)
I am also seeing lots of pictures where people have used the EVAP out of the older vehicle and not the new one the 3.4 came with. Is it better to use the newer EVAP?
Oh and the fuel line matches up. The 89 4runner had an adapter and once removed it fit the fuel line of the 3.4.
Regarding the Alternator connector for this swap, the wires from my 89 are much larger than the ones from the 97. Has anyone repined this connector or do you solder it? Whats with the big difference in wire gauge?
Thank you.
Last edited by potatohead; 01-03-2016 at 06:43 PM.
For my 89, repinning the alt plug would have involved splicing anyway, because the actual metal pins are a different style, and wouldn't have plugged into the connector housing. Once I determined that, I spliced mine with solder and shrink tubing as close to the fender as I could get it without ripping that whole harness apart, then I wrapped it all up in wire shielding.
Also, the fuel hard line coming off of the frame rail on my 89 had an adapter on it already, so at first glance it looked like the 3.4 flex line wouldn't bolt up, but once I removed the adapter, they did. I didn't intentionally take any pictures of it, but by chance caught it in this picture of the engine bay. It seems like if you had the same setup, you would already know because that adapter is pretty large and hard to miss, but I thought I would mention it. Good luck!
For my 89, repinning the alt plug would have involved splicing anyway, because the actual metal pins are a different style, and wouldn't have plugged into the connector housing. Once I determined that, I spliced mine with solder and shrink tubing as close to the fender as I could get it without ripping that whole harness apart, then I wrapped it all up in wire shielding.
Also, the fuel hard line coming off of the frame rail on my 89 had an adapter on it already, so at first glance it looked like the 3.4 flex line wouldn't bolt up, but once I removed the adapter, they did. I didn't intentionally take any pictures of it, but by chance caught it in this picture of the engine bay. It seems like if you had the same setup, you would already know because that adapter is pretty large and hard to miss, but I thought I would mention it. Good luck!
Thanks man. I did figure out the fuel line and it's hooked up now. Why do you think the wires are so much bigger on the older model? I would assume the amperage flowing through it so it worries me to splice them. Do you know if this is common?
I don't know why the wires are a different gauge. The ones on my 95 were the same as the 2000 Tacoma, and so was the connector, so I never had to mess with the alt harness. I've been running the 89 with the 95's alt harness for 4 months without any trouble, so I wouldn't lose too much sleep over it. The alt will be fine as long as you don't go smaller than what the factory used.
I'm wondering if I should try to use the 1989 alternator or if I need to use the 1997? The wires to the 97 are so much smaller I'm worried about splicing them. Anyone know what kinda current is traversing these wires and if it's okay to splice them?
I'm wondering if I should try to use the 1989 alternator or if I need to use the 1997? The wires to the 97 are so much smaller I'm worried about splicing them. Anyone know what kinda current is traversing these wires and if it's okay to splice them?
I spliced the 3.4 alt plug onto my 91's wires, those 3 wires are essentially signal wires and should be relatively low current, but are likely a large gauge to reduce any possible resistance in the wire. I haven't had any issues with mine since 2012.
The other option is to swap the controller board and rear cover from the 89 alt ont the 97 alt. There was a thread in here somewhere that covered it (a few years back) but I don't remember where it is.
Just joined but have been reading for a bit. I am in the process of doing a 3.4 swap into my 89 manual 3.0 4runner. I have pulled the 3.4 out of a 97 auto 4runner. I bought an ECU from a 99 tacoma. The plugs are the same on both the 3.4 ECU's but obviously not the wiring. I'm really questioning my sanity right now. I bought this 4runner with a bent frame, spliced and repaired that. The front of the frame is from a 4cyl auto. Since I'm doing a SAS too I just cut the motor mounts and all the suspension brackets. I bought all the EWD's for the 97 and 99. I also went to the dealer and took pictures of the 88 EWD's. Both the motors were leaking oil from all over! I have replaced the timing belt, water pump, front crank seal, cam seals, valve cover gaskets and cleaned all the oil/dirt that I could. Switched oil pans, baffle and sump with the 3.0.
A few questions I have are:
1- The fuel line off the frame and motor are female, is there an adapter I can get so that I don't need to buy a new fuel line from ORS?
2- Should I go buy a new radiator? The one I have now has a dog leg on the top orfice, I am thinking about taking it to a radiator shop and having them turn it or put a straight piece on it....thoughts?
I will ask more questions later as they come up.
Thank you.
hey potatohead ..is there anyway i could get a copy of your ewd... im starting my 3.4 swap on my 89 4x4 m/t sr5... and iam having trouble finding/getting my ewd for my 89 any help with this would be great thanks ..
10-30-2015, 02:58 PM
