pplusent

I have someone who want me to do a 3.4 swap in his 89 4runner. I haven't done the swap, but I would think it would be fairly simple. The thing I am wondering about is why change the harness and computer? The engines are very similar in design and use basically the same sensor inputs. I know the tach requires a mod and the alt, but other than that if it gets spark and mixture control and timing advance the engine should run properly. why is the 3.4 comp and harness such a necessity?
I have done a Fiero swap to a eight cylinder northstar engine and ran it just fine off the six cylinder Fiero computer and it ran perfect with slight mods to inputs. Then swapped the northstar out for a 525 cid hemi in the front, then needed new wiring but that is a massive change.
The two Toyota engines are so similar you would think that the 3.4 would run on the OBD1 computer. It's basic functions are the same it's just slightly different management. Has anyone done this?
The other questions I have is are the engine mounts in the same locations and are the transmission bolt pattern the same? I believe they are because the autos all have the a340 trannys, but I may be wrong on that.
And Is the swap worth the gains, or if doing a swap why not a nicely built 4.3 chevy motor. I can easily get between 240 to 300 hp out of a 4.3 or detune it for some real good torque numbers for under $3000 dollars including the rebuild. Reliability not being an issue, 4.3 is very reliable.
The guy wants the best bang for the buck, so what do you all recommend?

SacRunner

The ignition is 100% completely different between the 3.0 and the 3.4, where the 3.0 uses a distributor and a single ignition coil whereas the 3.4 uses an igniter with coil packs in a "waste spark" system. Add to that, that most of the sensors are different between the two engines.

Mechanically, yes, they are similar, very, very similar, but electronically, they are two entirely different animals.

Now, if you feel you know something that everyone else doesn't, feel free to try things out, and if you are able to make it work, please post up what you did, as I'm sure it would help out a lot of others considering the swap but who are hesitant because of the electronics.

The basic block is (as far as I'm concerned) 100% identical between the 3.0 and the 3.4. So, you use the 3.0 engine mounts, mounted to the 3.4 block and it will line up with the engine "perches" on the frame used by the 3.0; and also the bellhousing bolt pattern is the same, which is why guys have been able to mount the 3.4 to their existing 3.0 transmission (most common is the M/T swap, but there have been lots of A/T swaps too, its just that they're a lot more involved as the 3.4 ECU also controls the transmission shift points).

Lastly, check out the 3.4 swap forum here, there's way more info scattered amongst the various (and I mean various, read as many as you can stand, then do it again) threads than you could ever imagine, and it should help clarify many of your questions: https://www.yotatech.com/forums/f160/

Lastly, good luck with whatever option you pursue, and please post a swap thread, they're fun to follow along with (especially now that mine's been done and trouble free for the last couple of years).

pplusent

Thanks you gave me an idea that might work. I will look into it and see what develops.

wyoming9

iTrader: (1)

It all depends just what the end use of the vehicle is going to be

As to weather the 3.4 is a good fit

I like my 3.4 it does what I need it to.

fierohink

I would like to see pics of your wiring on your drop in north star swap since most people bring the PCM with the motor.

http://www.fiero.nl/forum/Forum2/HTML/058686.html

pplusent

Wow. That was a long time ago. There used to be a web site with all kinds of mods for the Fiero and I am not sure if its still there. You would have to do some research online to find it. I can look and see what I can find. I know the site sold new replacement sails for the Fiero and I think there may have been link on Rodneys Fiero parts. I remember there were six pins on the ECM harness that had to be re arranged, it was really simple. That was a great car, fun and the most reliable car I ever owned. I have another one now I am trying to decide what engine I want to put in it although this one is a 2m4 with the iron Duke in it and gets 36 MPG. Anything more powerful than a northstar you need to put the engine in the front. the car gets to light in the front end over 140 MPH and will try to fly. With engine in front it can handle speed up to 200 mph.
Good luck with that one, the sky is the limit on what you can do with them.

fierohink

M not discounting the fun of the car I find it hard to believe that you were able to "drop-in" a ridiculous more advanced motor and run it of an ALDL computer without even swapping PROMs.

Considering the 2.8 ran a distributor and the N* runs DLI. As well as firing order for 2 additional injectors, etc.

Basically I'm calling BS without pics. And the link was as an example of one of many conversions that requires the donor computer.

The only true plug and play fiero swap that I know of was the 3.4 as it was a bored out2.8 block

So if you are interested in a 3.4 conversion in your 4Runner, you can either follow one of the many well-documented swaps, or use your extensive conversion skills to pave your own way.

pplusent

On the Fiero post; the chip was reprogrammed for the Northstar and I think I found the site, but that link comes up with domain name for sale. The link on the site was pm a Fiero sail site. under Fiero Secrets. You have to remember the article was back when the swap had just started. Now they are using LS1 engines. Don't have any pics, lost all that in my last divorce. I only have a picks of my ISCA show car Corvette, but that is only because it is on a magazine cover.
Sorry you don't believe it,but it was done. We are doing a mod on my wife's Firebird making the opti-spark distributor into a coils over system and still retaining the distributor indexing to keep the sequential fuel injection running. Cool stuff. See ya at the drag strip!
Thanks for the info on the 3.4. I will take pick on what we do with it. I photo document all my engine builds now. I have a fresh 3.0 if anyone is looking for one here in Arizona.

Greg_Canada

It would take significantly more work to mod a 3.4 to run a distributor, than it would be to patch in the 3.4 harness/ etc. Also, why would you want to downgrade and have less HP / reliability?

pplusent

Just seeing if there could be a cost effective way to make a truly drop in solution that would not sacrifice performance. With the availability of some of today's electronic systems hp could be increased not decreased. It is looking like it would not be cost effective due to low demand for a bolt on kit.
Performance can always be increased, just look at drag racing. 30 years ago funny cars barely broke 250 MPH, today they are running 300 + , pro stock has just broke the 215 barrier, and some production cars are producing up to 500 hp. These thing would never have advanced if people didn't re-engineer what some other person created. I worked research and development for years and I would bet you Have a product I helped developed on you right now. Things can always be improved upon.
I have found now that there is an alternative to the 3.4 swap. There is a company that builds a 3.0 for $1995 that matches the HP of the 3;4. The engines are completely re-machined, have all premium parts and the cut their own performance cams for the 3.0. RPM ranges are different than the 3.4 but HP meats or exceeds the 3.4 and there is no swap needed. www.raptorengines.com

UGR

uh, ignore this reply, somehow I replied to the wrong thread