Well, I'll be doing the 3400 swap starting around April. I've been told by someone already completed the swap, that it very easy to use a 1994 Z24 Harness and PCM to wire the engine, and mate it to the stock harness and PCM to run the gauges. I don't know of anyone else who has done this. Everyone else seems to be using some sort of tuning methods. Which is better to go with, the Z24 pieces + stock pieces, or Megasquirt or something of the sort?

Edited 1 time(s). Last edited Sunday, September 16, 2012 7:06 AM

Anyone?

Since you're not mentioning what car this is going in, its hard to say... either case, you need to splice into the harness if a third gen, so whatever your preference is.

it's going in a 97 2.2, but which would be the easiest way about it? I know nothing about MS, but i have a buddy who can help me out with it.

Since I used the 3400 harness and extended it to go where the stock J computer went, total time spent playing w/ the wiring was about 40 hours (including the harness extension part) I need to double check 2 wires to the O2 sensor, but that's about it.

Apparently, the 3400 computer will fit up under the dash, so to cut down on some of the time, a hole saw will work to make the space for the grommet to go through.

why do you want to use older electronics with a newer engine??
check the 3rd generation sticky

Forgot about that part...

If emissions is required don't use the OBD1 setup

How did you use the 3400 harness? Did you combine it with the stock harness? I'm confused on your wiring technique. Please explain what you did... You used aftermarket gauges if I remember correctly. I'll be using the stock cluster, and I don't think the 3400 harness will work with stock cluster....

there are a handful of wires that need to be spliced into the 3400 harness at various points (heated 02 sensor, various 12v+ switched wires, fan control, AC control, grounds...) those come from the C100 connector (the big plug under the brake booster) and 5 if I remember right from the underhood fuse panel. I can't say what all needs to be spliced in as I went wire by wire, but having the wiring diagrams help (I posted all the 3400 ones in the third gen sticky)

The 3400 harness doesn't have enough length to make it to where the J computer is... the plugs end up right under the trans, so I extended them using a second harness that I had:



If you are piggy-backing, that I have no clue how to accomplish, so someone else is going to have to help out.

That didn't answer my question, did you use ONLY the 3400 harness? how did you get it to work with the gauges?

I used two 3400 harnesses and a little bit of the J harness fron the C100 and fuse block.

I'm using aftermarket gauges, so I after tapping into the appropriate sensors and putting in 2 sending units for water temp and oil pressure... I can't say how to hook it up with stock gauges.

I'm going to go with the 2nd Gen harness. Emissions is not a big deal to me, I have never had to, or heard tell of anyone doing an E-test in my area. Kardain, what bolt-ons are available for the 3400, I'm having mine rebuilt before it goes into my car, so I want to add some bolt-ons, but it'll stay NA. I'm looking for around 225 HP to the wheels if possible.

headers, but clearance to the radiator is tight as is

intake

3500 head swap

larger TB

ported upper intake manifold

http://www.60degreev6.com/store/index.php?act=viewCat&catId=10

The best way to put a 3400 n/a is the way I told you in a pm on lotnight.com. I think everyone here will agree, use a pcm and wiring harness from a 2 nd gen v6 cavalier 5 speed and run it to all sensors on the engine and provide it with power and ground and leave your 2.2l computer in place for speedometer, gas guage and the temperature guage you can use a 3 wire coolant sensor and share the guage and the z24 pcm, you will have to do the cooling fan relay mod to activate the cooling fan if need be and also you may want to slplice the injector clips from the 3400 engine to the z24 harness if they are different and also check the impediance of the injectors and compare to the year of z24 you use the pcm from, make sure you use the same. I think I have outlined anything there but if not just e-mail me and I can answer any specific Q's. The only reason I used megasquirt is for boost and the fact that I could tune with a wideban and setup timing, all of these are accounted for when you use the z24 pcm.

Later, JOnathan

Thanks Johnny. I was under the impression, that when you use the 2nd gen. harness and PCM, you'll need 3100 injectors, but it took away a little power. If you get the chip burned for the PCM (z24) you can use the 3400 injectors and it run alot better.
Also, if I can find a company that can reflash a 3400 PCM and remove all the automatic features, would I be better off using the 3400 PCM and harness? The wiring is the only thing that's bothering me with the swap.

Go with the Megasquirt-II You'll still need your factory PCM present, to run some of the other stuff. I went with the 2nd gen Harness and ECM, and it sucked. When you go with the OBD-I setup it sucks, you'll have to set it up. THEN you'll have to go through and have a custom chip burned for it. If you dont hook up the VSS to the computer the idle will want to stay at 2300 after a drive down the highway for about 5 minutes. If you have too old of an ECM, the VSS in your car wont be compatible so your top speed limiter will kick in at about 20mph.
(*NOTE* Make sure Megasquirt-II so you can run fuel and ignition)

And then you have to go about deactivating all the emissions controls. That will need burned into the custom chip. Seriously, go with the Megasquirt-II. In the end, it's going to be a lot less effort. (although, with the megasquirt I suggest picking up the injector harness from the old 3.1 anyways).

And if you decide to go that route, throw me a PM and i'll pass my latest tune to you.

I don't think there as much trouble to it as that. The 3100 and 3400 are very similar engine. I'd have to get an 02 sensor from a 97 chev venture. Other than that it's pretty straight forward according to some.

Here's what i did, and i got the swap done in a weekend.

Got an engine(3100), harness and computer from a 94 grand am.

With the engine on the garage floor, plug in the entire harness onto the engine. After everything is hooked up take all the tape and loom off the harness. All the sensors/plug-ins that are not uses(auto trans,abs stuff like that) can all be cut and take out from the harness. Now before you go chop happy, look at the wiring diagrams for the wires that go in the instrument cluster for the gauges/dummy light and label them. I isolated the check engine light, tach, the green wire from the second coolant sensor, the data link wire and all wires that give power to the computer. Now connect all the wires that will need power with the key in run/start and to a wire and bring it near somewhere that you can connect it too. It's also a good ideal to take the un-used wires on the ecm end out of the connectors so they don't touch and possibly fry the ecm. Now you can loom back up your whole harness and make it looks stock if not better.

After that is done, you can kind of test fit your harness and find a good place to put it. i cut a square out of my fire wall and mounted the ecm right under the glove box and used the stock rubber gommet. Then install the engine, hook up the harness connect the acc lead and your pretty much ready to fire it up.

I also found out that if you connected the green coolant wire to the yellow coolant temp wire on the factory harness, the gauge works. I'm still not sure if the fan kicks on because it hasn't gotten that hot yet, and it's pretty cool out now.

I might have left out some details out of that, but that's pretty much the gif of it. My car rolled in my garage friday night as a 2200 and rolled out sunday afternoon reborn as a 3100. I've put nearly 150 miles on it so far and it's working flawlessly.

Dxray, what splicing of the harness' did you have to do? Why would you cut off everything from the PCM like ABS? I know your not going to need the tranny wiring but, I'd still want ABS.

Eww.... a small port 3100. LAME!

Suggest, once you get it going satisfactory to your liking that you swap the top end to the one for the 3400 (or the 2000+ 3100 engine is the same) so you can tap more power from it. The 94-98 3100 is just a few HP over the 2.4. Granted it's got the torque advantage, but the 00+ 3100 is 170hp. Will be a nice feel for an increase. Though, the additional airflow might throw your fueling off a tad.

Agreed, If I'd have done your thing, I'd have definetly ditched the 3100 as soon as you had the wiring done andit fitted.

SHOoff wrote:Eww.... a small port 3100. LAME!

Suggest, once you get it going satisfactory to your liking that you swap the top end to the one for the 3400 (or the 2000+ 3100 engine is the same) so you can tap more power from it. The 94-98 3100 is just a few HP over the 2.4. Granted it's got the torque advantage, but the 00+ 3100 is 170hp. Will be a nice feel for an increase. Though, the additional airflow might throw your fueling off a tad.

The whole swap including new lower intake gaskets and fluid cost me 400$ How is that lame?? I'm gettin a 3400 for next summer that will be plug and play in my car and besides, i'm driving my car over the winter.

I cut the abs out of the 3100 harness because you keep the abs on your stock harness. Also mines not hooked up because i hate driving with abs.


660 powered sunfire

I also hate the ABS, I unhook it for dec. - jan.

When you did your harness with the engine out on the floor and cut away what you didn't need, what did you do with the rest of the wires? the wires for the gauges, engine light, data link, and all that other stuff. Where did you run those to?

Also, what harness did you use? was it originally from a 5 spd or auto? If auto, did you need to re-flash the PCM for it to run right?

Dxray wrote:

SHOoff wrote:Eww.... a small port 3100. LAME!

Suggest, once you get it going satisfactory to your liking that you swap the top end to the one for the 3400 (or the 2000+ 3100 engine is the same) so you can tap more power from it. The 94-98 3100 is just a few HP over the 2.4. Granted it's got the torque advantage, but the 00+ 3100 is 170hp. Will be a nice feel for an increase. Though, the additional airflow might throw your fueling off a tad.

The whole swap including new lower intake gaskets and fluid cost me 400$ How is that lame?? I'm gettin a 3400 for next summer that will be plug and play in my car and besides, i'm driving my car over the winter.

I cut the abs out of the 3100 harness because you keep the abs on your stock harness. Also mines not hooked up because i hate driving with abs.

I say lame because of the lower output of the small port engine. Going with the large port top end you'd be overly happy. Or, the whole 3400 works as well.