(apologies in advance if some of my questions have been answered before, which i imagine they have...either i'm searching for the wrong things or searching in the wrong places, or both )

hello.

i have recently found out that i essentially need a new engine for my 1994. after asking about my options in the 86-95 forums (here, for a run-down), it seems as though the majority opinion is to go with the 3.4L swap.

while i would like to try and do this myself, i just dont think i have the knowledge and/or resources to do something this major myself. i went to an engine shop last week to ask them about installing a new engine, and mentioned the 3.4L engine swap, but they havent heard of it or done it themselves, but he said that if i brought them some instructions or some sort of roadmap they can use then they would see what we could do. he even said that they like to try new stuff like that, so i personally found that sort of reassuring in that they are eager/willing to try new stuff like that.

so during my research, mainly through the forums here, i thought i had everything down pat. found my way to ORS and grabbed their install instructions and started to give it a read. then much to my dismay, i got to the part about the automatic transmission not being compatible with the mod/swap. so then after some more researching, i finally made my way to this lovely 3.4L swap section, yay! and much to my chagrin i came across this promising thread, saying that the stock 3.0L transmission will work with this swap.

so now some of my questions so far...

option 1 questions-
what are the catches/caveats, if any, for sticking with the stock transmission? from my understanding, there shouldnt be too much issue...main issue being having to do with the speed sensor? other main issue being that it cant handle the extra power/torque in extreme circumstances, particularly if adding a S/C?

option 2 questions-
preferred alternative seems to be finding a T100 4WD auto transmission and putting that in, correct? if going that route, it seems as though one would (preferably) need a T100 with matching T100 4WD auto transmission? if swapping transmissions, one catch is that a new gearshift will have to be installed in the console, with a little modifications as well? does this particular transmission have the "built-in/all-in-one" transfer case like the stock 3.0L, or would i need to track down one of the aforementioned gear driven transfer cases? if a 'matched' T100 engine/transmission cant be found, what are the catches of finding just any old 3.4L and mating it with said T100 transmission? (luckily though, i may have found a paired T100 engine and transmission, if i should go that route!)

general questions-
and finally (for now at least ), it seems as though for simplicity's sake, that i would want to avoid the "drive-by-wire" engines...which particular years would i want to stay with to keep to this reasoning (ie, 96-99)? is there a 'holy grail' engine that people generally like to stick with (thought i read a 98 T100 somewhere)? or for the most part is a 5VZ-FE is a 5VZ-FE is a 5VZ-FE is a...? aside from certain updates throughout the years (ie, drive-by-wire, etc).

oh, and if it helps with any of my questions, my driving habits are pretty much every day, to/from work driving...nothing like crawling/digging/mudding/etc...the most 'heavy' driving i would do is towing a boat, or a 3-4 hour road trip (up to 70mph speed limits), on fairly flat terrain. worse case, so-to-speak, would be driving on the beach and/or a camping trip in the mountains across some old fire roads/trails to get to the campsite. and unless or until i get into anything 'heavy', there's no immediate plans/aspirations to slap a S/C in either.

oh, and the truck ins question is a 1994 4runner sr5 3.0L 4WD auto.

again, apologies any of this has been answered in one way or another...i'm just trying to get my homework done before taking the plunge, particularly since i may be taking it to an engine shop to get the work done, so i want things to go as smoothly and easily as possible

thanks.

 

I hear your CEL will be on all the time because of that speed sensor issue, unless you use a T-100 ECU. I don't know about you but it would drive me nuts to have the CEL on all the time.

You might call IPT (http://www.importperformancetrans.com/) about possibily running a SC with your A340H tranny. But in general the T-100 ECU doesn't handle the supercharger fueling adjustments as well as the later model 5VZFE ECUs did, especially the models that used a front air/fuel ratio sensor instead of the old style O2 sensors. IIRC the first year Tacoma to use an A/F sensor was 2001.


Not in my opinion. IMHO the preferred route would be to use the auto tranny that was in the same truck as your donor engine and ECU (what ever year that is) and then using a Marlin adapter to mate that tranny to a gear driven transfer case.

The drive-by-wire throttle body Tacomas started in late 2002 or early 2003. Much earlier in the 4runners. Also be warned there are some factory chipped ign key issues with the 4runner ECUs. I'd stay away from the 4runner ECUs because of those possible problems.

Also after about 99 the 5VZFE block has to be drilled for the dipstick relocation. Before that Toyota was still drilling the block (for some reason) and then plugging the hole.

 

yeah, while i would prefer not having the CEL on, but if that's the only issue with keeping the stock transmission then i can live with that for now...i just wanna get my baby back on the road and as far as the ECU's are concerned, they should technically come with the engine, right? at first i was thinking it was under the hood somewhere, but after reading through a few project threads, its behind the kickpanel? and if it's not that shady of a salvage yard, it would be included with the engine (if it wasnt already parted out). so theoretically speaking, if i find a T100 engine with ECU, i should be good to go with everything, as it uses the same speed sensor configuration?

as far as a SC is concerned, that is a non-issue (at least at this juncture)...this is just my main/daily driver that just seems commute time, with the occasional boat tow.




right, that would be the preferred option#2, but i was just trying to cover all the bases should i have to resort to something like that, since some of the 3.4 swaps posted have gone with a T100 tranny. luckily, i think i have found a T100 engine and tranny locally (they both showed the same year, mileage, etc, so i can only assume). so if i did have to go the T100 tranny route, it's not the "all-in-one" tranny/transfer, so i would have to find one of the gear driven transfer cases to mate to it with something like the Marlin adapter?

---

overall, my main concern with the auto transmission issue was if it would effect the drivability and/or mechanics of the truck...ie, the tranny getting fussy when trying to pull the boat out of the water from the extra horsepower, or any funky shifting while i'm cruising down the highway, or just anything like that. if it's just a CEL, while annoying, i think i could live with it for now, considering the overall advantages of putting in the 3.4L.

---

ok, and just a little re-cap so far, if nothing else for my own sake...

option 1 (stock 3.0L tranny)-
so the stock tranny should be suffice, as long as i can put up with a CEL, unless i am able to find a corresponding T100 engine and ECU. and as long as i dont plan on adding a SC or anything, i should be ok mechanically.

option 2 (+T100 tranny swap)-
if going the T100 tranny swap, then i would need a new transfer case + marlin adaper as well. in addition to a new shift column and some center console modding.

in general-
want to try and keep it pre-99 if possible, to avoid drive-by-wire headaches, and preferably T100 for appeasement of stock tranny complications.

as always, please correct me if my figurins' are wrong

thanks again for any and all input.

 

Unfortunately, I'm not able to shed much light on your automatic dilemma. I can attest to the fact that the truck has much more power than the 3.0, even if you stick with the naturally aspirated version of the 3.4.

I can also tell you that this was the biggest project I had ever tackled and even then, there isn't much there that is tough to do, so if you have an engine shop doing the work, it should be a breeze.

One of my favourite sites, and one of the ones I used the most, is Andrew Zook's site: http://www.andrewzook.com/content/view/22/48

While it won't help with the automatic, either, it does give you a bunch of the little details you might want to let your mechanics know ahead of time.

Good luck and if there are questions I might be able to answer, let me know.

 

I see no reason to go to a T-100 tranny, where are you getting that?

Like I said Tacomas didn't go to drive by wire until late 2002 or early 2003.

 

yeah, i borderline wanna give it a go for myself, but then i start over-analyzing it and start thinking about this essentially being the heart of the truck, which is something i wouldnt wanna risk borking up simply because i dont know better the shop's eagerness/willingness at liking to try new things was a little comforting, plus there's an exhaust shop right around the corner from them which they said they could take it to once the crossover came into play.

and yep, thanks, zook's site was one of the first one's i bookmarked when starting my research



here are two of the T100 tranny projects i was using as a reference as to where i got it stuck in my head about the tranny swap (looks like the one pertains to a 89 truck and not 4runner...guess i just have 4runner on the brain perhaps because his donor was a 4runner, who knows, bah, sorry)

4runner - T100 3.4+tranny

truck - 4runner 3.4 + T100 tranny

see, you just saved me a transmission, granted it took one of these and then one of these didnt even make it to the 3rd strike though!


alright then, that certainly simplifies things...re-cap, rev. 2:

option 1-
plan a) find a T100 engine and ECU, all systems go, no CEL (at least from the speed sensor issue).

plan b) find a pre-2000/2001 3.4L (to avoid drive-by-wire), preferably tacoma (to avoid the minute 4runner differences that can cause headaches), and try to live with a CEL.

option 2-
disregard, see option 1, and/or refer to mt_goat for some more

well then, i guess i can start doing some more legwork in finding an engine now i already know of a few places locally that have a handful of 4runner 3.4's...one of which only has about 60k miles (naturally is one of the most expensive at 2500). when i thought i was going to have to slip in a T100 tranny, i came across a T100 engine with about 100k, as well as what i believe to be its matching tranny (same specs, mileage, etc).

thanks.

 

Mt Goat is correct IMHO as well. Find a Taco with low miles auto 4x4 and buy the marlin adapter. The t-case isn't too hard to find. If i could do it over again that is the route I would have taken. I haven't had any issues with my T100 transmission or my swap in general (except the stupid exhaust which someone else did) but I still wish I had bought a Taco setup. It's a little more expensive but I would much rather have an 00 or 01 motor and ECU for a number of reasons. Just my two cents

 

alright, just a mini-update, i think i've found a worthy donor...a 98 T100, for which the place seems to have all the other goodies, should i need them. so this should solve all my false/initial woes, correct? stock 3.0L tranny w/ T100 3.4 and ECU, check; mechanical, non-drive-by-wire throttle, check. i havent seen it or talked to the place yet, so i dont know the exact condition. i still need to take my homework to the engine shop and see what they say...he might be able to check with his connections as well in terms of finding a wider selection, and discounted prices.

so far so good?

thanks.

 

Make sure to get the donor engine harness too (hopefully uncut). You want the engine, engine harness, and ECU all from the same truck if at all posssible because it makes the wiring conversion easier. Also get the VIN# from the donor truck.

 

Definitely get the VIN# from the donor. The T100 block does not have a VIN plate on it like most the 3.4s. The one issue you might have is the connectors on the 340H versus the connectors for the T100 transfer case. I think there are 4 of them. I'm not sure they are the same. Make sure your wiring harness and ECU are correct too.

 

my plan was to do a straight engine swap, no transmission or transfer case involved...did i interpret something wrong, and will need to look into the new transfer case also?

as that was the main reasoning behind looking for a T100 engine, since the transmissions use the same speed sensor, so it wouldnt be throwing any codes or CEL for that issue, thus not needing to do any transmission/transfer swaps/modifications.

oh, and now that you mention it...if for some reason (and for my own curiosity on the matter) i do have to or want to swap (auto) transmissions, is the T100 tranny (A340F?) more or less a direct swap in this application? i thought that i read that the T100 transmission had the passenger side front output and transfer case, in the same manner as the pre-95 4runners (current project/application)? just did some more scouring, and looks as though the A340F's transfer case is manually actuated as well? and for posterity, here is where i'm basing some of my assumptions on. looks like this would be a case where a new shifter and center console/floor modding would come into play?



again, sorry for any seemingly repetitive/redundant questions, just wanna make sure i have all my homework done, especially since i will probably be having a shop do it...so less time they have to spend on it = less costs for me

thanks.

 

I think Kowboy was refering to the electrical connectors. The auto transmission is electronicly controlled by the ECU, so there are connectors that may be different and other wiring issues. You or the shop you've selected will have to get EWDs for your truck and the donor truck to make a wiring conversion harness. That conversion harness mates the donor ECU to your truck's body harness and your auto tranny.

 

gotcha. that's involves that whole wiring harness part, correct? ie, where most people's time and headaches are spent with the swap? and that's where ORS's plug-n-play harness came in to play (when they were still open)? or is there an extra step i should look out for involving? i was already anticipating having to go to that one 10$/day tech site and download all the files/manuals i needed once i found a happy donor.

thanks.

 

My memory is a little foggy on it now, but IIRC I think the auto tranny harness was part of the engine harness. I didn't do my conversion wiring harness (ORS did it), plus I used the donor tranny too. I'm using a 2001 Tacoma engine, tranny, and ECU.

 

You remembered correctly, the tranny harness is part of the engine harness. After the swap I had about 5 connectors on the tranny harness that were no longer used and I don't know what options a couple of them were for.

 

Now that you mention it I have a few extra too. I think they were for the Tacoma transfer case (which I'm not using).

I guess that may be a good reason to use the donor tranny. The wiring may be harder using the old A340H. Brian, "thefallman" may know more what's involved.

 

There are some sensors on the T100 Tcase that tell the ECU what position it is in. Some of those sensors trigger the ECU to activate the ADD system that will engage the front differential. It also has some other purposes. I don't know (or remember) how the 340H connectors work. It is hydraulically controlled but there are some electrical connectors on it. The 4x4 auto T100 harness will have 4 plugs at the end of the transmission "leg" that are supposed to plug into these sensors. I think you can make them work just fine with the 340H but you might have to splice some wires at the transmission as well as in the kick panel for all the 4x4 "stuff" to work correctly. Brain "thefallman" is way more knowledgeable about this then I am. Did you read this thread?

 

ah, so then the 10000$ question...will those "extra" wires effect anything...? ...or, quite possibly, will nothing be amiss, since i'm hoping to use a T100 engine and ECU vs a tacoma?

and since we're sorta back on tranny's, for my own curiosity from my previous post...

oh, and now that you mention it...if for some reason (and for my own curiosity on the matter) i do have to or want to swap (auto) transmissions, is the T100 tranny (A340F?) more or less a direct swap in this application? i thought that i read that the T100 transmission had the passenger side front output and transfer case, in the same manner as the pre-95 4runners (current project/application)? just did some more scouring, and looks as though the A340F's transfer case is manually actuated as well? and for posterity, here is where i'm basing some of my assumptions on. looks like this would be a case where a new shifter and center console/floor modding would come into play?

i'm guessing syber_kowboy would be a good source for info on this option



**edit: looks like syber_kowboy is a faster typist than me and replied while i was replying yes, i have given that thread a read, i'll have to give it a more thorough reading when i get home from work (admittedly i started to get a little lost when there was talk about getting an elec eng on board ).

would it be in my best interest to just go ahead and nab the mated T100 tranny and slap that in? would that be a 1:1 swap or would there be some mods involved? looks like syber_kowboy only had to modify the floorboard and center console? that way i wont have any of those tranny related wiring woes with extra wires, and splicing and whatnot? speaking of which, do you have any updated/finished product pics of the shifter/console, kowboy? as well as any updates on the cruise, AC, and ADD?

thanks again for all the patience and info guys.

 

just an update/slap on the wrist for myself...home now and just finished re-reading the FYI tranny thread, and found my answer...

my apologies if i caused any frustrations or moments for anyone.

 

No worries what so ever. Brain knows a crap load about the 340H vs T100 transmissions. I went with a T100 because my 340H was slipping and had like a million miles on it. If your 340H is good you should definitely use it. As far as those plugs on the Tcase are concerned, the only reason I brough it up was because I think the actual physical plugs are slightly different so you might not be able to just "plug" them in. You might have to use some stuff off your old harness and change the plugs from the old 3.slo harness to the 3.4 harness. Didn't look close enough when I swapped mine. I have been using the truck without the console installed. I just ordered the correct plastic cover for the shifter today from Toyota after getting tired of searching for a used one. I have the ADD working just fine now, but haven't hooked up the cruise or AC yet.

JUST FYI - If you decide to use a T100 transmission you have to get a crossmember and tcase mount bracket from a manual truck or 4runner (4x4 obviously). Here is a picture but the labels are flip flopped