I'm putting a 914 2.0 in a Type 3 and using a type 4 411/12 FI harness. Trying see those little numbers on the white wires in the harness is a PITA.

It was my thought that the 4ll 1.7 and 914 1.7 was exactly the same. I've only found 1 difference. The throttle valve position switch on the 914 has one more wire than the 411. I had to swap the plug ends and add the #17 wire from there to the computer end of the plug. It is now on the outside of the gray wire wrap, oh well.

Does anyone else know of any differences I should know about?

Not too familiar with the differences for the T3. But...

I'm not sure of any differences. AFAIK, the stock T3 FI experience here is pretty low.

It it were me, I would use the 914 harness and connect it to the T3 body harness. Since then it's just a matter of a few power wires.

I have built a few 1968-69 T3 FI harnesses and have a wiring diagram for free download on my wiring harness website, as well as all the 914 harnesses. You may be able to figure out the circuitry from there.

I have never seen a T4 harness, so unless its identical to the 914 FI harnesses, you would need to review each circuit...the wire numbers likely do not tranfer from one platform to another 100%. The T3 ECU is not a good fit for the 914 engine components if that is what you are trying...I assume you will use the 914 ECU.

One word:

MEGASQUIRT!!

If you are going to be using 914 2.0L components with the 411/412 harness, I would bet you will be running into issues and can see a lot of this in your future. . .

OTOH, I would expect that as long as the injection system matches the harness, it will only be a matter of a couple power wires and grounds. Then mounting the brain box.

Did I mention MEGASQUIRT?? It's the right thing to do. . .

MegaSquirt is an extreme solution to a non-problem for a stock 914 or stock 914 engine... It may be an approach that some want to take for any one of several good reasons, but its by no means the only or best solution.

Why not just use the 914 FI harness?

I am definitely using the 914 computer. I spent another day looking at this and the T4 harness has all the right wires in the right places. I have everything figured out in the car except for one of the fuel pump wires.
One of my problems was that the FI in the Fastie was removed and the engine was fitted with carbs (which would boil gas every time it was driven).

Also the T4 harness has an extra long pig tail (see below, the t4 is circling the 914), so the box can be mounted under the rear seat. The T3 engine bay was not seal from below and computer was mounted in the driver side fender.

If I was to do aftermarket it would be SDS, sorry Megasquirt fans. SDS costs a little more in the beginning but it works out of the box.

Thanks Jeff.
and here you go Rick

Cool project.

Post more pictures.

John

That T4 harness is Loooong....it looks in great shape, must not have seen much use. I'd love to document that if there was a way.

Yes Jeff - It is in excellent shape, minus one injector plug. I bought it last year from a guy for, wait for it.......
$25.!

The FI harness should match the ECU being used

ok I just looked at the pictures here. Is that engine in the picture the one you are using? If so it has 1.7 heads and injection? Are you sure the displacement is 2.0?

If it is actually a 1.7 I would just get an early ECU and TPS and use the 411 harness as it should all bolt right up.


If the displacement is indeed a 2.0 (with 1.7/1.8 or Bus heads) then you are probably going to need to sort out a lot more with that injection system.

The engine is a 2.0. It is somewhat of a Frankenstein. 2ltr case, crank, rods, p/c's, modifided 1.8 heads, 1.7 fi components with 2.0 injectors, dizzy, pressure sensor and computer. It also has a mild cam & couple of other mods so it will idle. :-)

The injectors in that pic are yellow, so they're 1.7 ones. The 2.0 injectors are green.

--DD

You are probably going to have a bit of fun getting it tuned right with this combo of d-jet parts and sticking with a stock ECU. How are you compensating for the lower flow of the 1.7 injectors?

If it were me, I would just swap the ECU for megasquirt and make your life easy, but then i am probably more familar with megasquirt then most. Having setup a 2.0 motor with 1.7 injection parts (using megasquirt) before ill point out a couple of my observations. The 1.7 intake components will restrict your power a bit and with the stock oil bath air filter throttle response becomes complete garbage. The 1.8 intake setup flows better (the intake runners are the same size as the 2.0 ones) and if you want to go even larger the vanagon 2.1 throttle body will bolt to the 1.8 intake and is 50mm (2.0 914 is only 46mm) theissue with still using d-jet with that setup though will again be the TPS.

if you are going Frankenstein anyways, might as well get the most out of it

james, the vanagon tb would be good upgrade for use of the ljet on a 2.0 engine?

k

It would probably depend on what manifold you were using. Its pretty much bolts striaght up to the 1.8L manifold as the vanagon manifold is very similar, if you are using the 2L 914 manifold then not so much. The other 2 things you would need to address is 1. the cable pull on the vanagon throttle body is setup for a rear engine configuration so that would need to be modified if used in a 914 and 2.Its been a while since i looked at an l-jet TPS but i think there might be some mounting issues there as well. Ill have to go poke around in my garage and see as I am pretty sure I have both sitting around somewhere.

I am not as familar with L-jet as I am with D-jet and megasquirt, so I cant say for sure if just increaseing the throttle body would help anything. I would guess any increased airflow might still be restricted by the l-jet AFM, but i really have no data to pull from here. Then there is also the question of would your engine even bennifit from a larger TB? It would probably make more of a difference on a hot 2056 that needed the airflow then it would with a stock 2L.

Interesting thread. I have access to a bunch of t3's. Three of them are complete but not running. Also one 411 or 412, don't know the difference, but it doesn't have the motor or tranny. Not sure about the wiring harness. The complete ones are mine but my friend has a bunch of bodies as he used to drag race a t3. The old race car has a roller crank motor in it setting out in the pasture. He used the automatic tranny. Lots of those also.

I'm going hunting in the am. I will look at the 411 if I can remember.

Whoa, everyone, hang on, hang on.... This engine has already been running in a 914. And quite well I might add. It has a few mods to run with the cam and It pulls really strong. Better than most I owned over the years. I'm only changing the harness (and the car). And yes they are the 1.7 injectors. Forgot... I'll post numbers from dyno after its all done.

Yeah, that is why i am curious what was done to make the system run well on a cam'ed 2.0 with all 1.7 injection? Fuel pressure increase, MPS tweaks?

OK, so with a little help from a few guys on the t3 forum, I have located all the FI wiring points. There was no central plug like on our 914s, which I already knew. But I thought I would find everything I needed under the seat, which is why I wanted to use the T411 harness. Well this was not the case, so I'm back to just using the 914 harness, and putting the computer in the fender well, hopefully...

James the mods are exactly that, in addition to an adjustable resistor on the head temp sensor, with a pot on the dash, and "controlled" air leak in the dizzy vaccuum line. And the cold start system has been removed, injector and temp sensor. This was all done with the help of a few knowledgeable friends several years back.

Jeff, this harness will now be available for you to inspect. I'll PM you later and we can work it out.

Someone's been playing injection nerd lately!

Here we are today! Egine is in. Didn't have to beat on it too much. I did have to remove the cooling air intake I had fitted and the rear 914 tin, which I think I will cut down and re-instal. I just need to hook up wiring, bolt on exhaust and mount cross bar. And keep fingers cross...

oh and I also will need a longer/custom throttle cable.

now if it just had a 901.