TheSamba.com :: View topic - Converting Digijet to Digifant. I NEED HELP

Wed Oct 04, 2017 2:38 pm

My VW mechanic is about ready to give up on this project;

I am attempting to convert my ‘84 westy from digijet to digifant because I bought a ‘89 syncro motor that came with a rebuilt ECU and engine harness.

So far my mechanic has my wiring harness up to my fuse box in the dash taken out. He has a donor wiring harness and fuse box coming from a ‘90 vanagon, but is hesitant to continue past the fuse box because then he’s afraid he’ll essentially have to re wire the whole van and won’t be able to do it in any realistic timeframe.

What are my best options here? Should i tell him to just put my harness back on? should i tell him to strive on? Should we approach it a different way?

help

Wed Oct 04, 2017 3:05 pm

Your mechanic needs to read the wiring diagram.

The fuel injection system is a self contained harness coming from the digifant/fuel pump relay box in the engine compartment.

Dave

Wed Oct 04, 2017 3:10 pm

djkeev wrote: Your mechanic needs to read the wiring diagram.

The fuel injection system is a self contained harness coming from the digifant/fuel pump relay box in the engine compartment.

Dave

Can you be more specific? I know the plugs from the Van didn’t match up with the wiring harness the motor came with.

Wed Oct 04, 2017 3:17 pm

you only need to connect to the engine harness plug in the black box

see images and diagram wires on this page.
http://subaruvanagon.com/tom/Getting%20Started.htm

Wed Oct 04, 2017 3:20 pm

That was a major screw up on the part of your mechanic if he was the one who decided to swap the vehicle harness. That was completely unnecessary!

The Fuel Injection harnesses have very few connections to the vehicle harness. The minor differences in the other engine compartment wiring could have been dealt with easily by splicing a handful of wires.

NOTHING needed to be done in the dash area.

Mark

FreewheelinWesty wrote:

Can you be more specific? I know the plugs from the Van didn’t match up with the wiring harness the motor came with.

Wed Oct 04, 2017 4:13 pm

this is what I had coming from the black box, the connectors wouldn’t match up, and this motor has “stuff” on it that a 2.1 motor has that a 1.9 doesn’t.

im not 100% sure, but i don’t think it’s as simple as a couple simple splices in the engine harness.

can anyone help me with the specific wires that would have to be spliced, and the wires that wouldn’t?

Wed Oct 04, 2017 4:36 pm

Do you have a Bentley with the wiring diagrams?

If not go spend $100 and get one, this investment will save you $1000's over time.

As mentioned, a bit of simple rewiring IN THE ENGINE COMPARTMENT and you're running!

Sadly, who knows what your well intentioned "mechanic" screwed up in the dash and the harness to the dash.

He has taken a simple job and possibly turned it into what could be an enormous rats nest!

Guess who will be paying for his On the Job education??????

Dave

Wed Oct 04, 2017 5:07 pm

Since I have converted 84 vans to 2.1 engine/cooling/Digifant systems I am 100% sure how simple it is with the right parts. You need the Digifant fuel injection harness for your 2.1 engine.

That fuel injection harness is separate from the other wiring except for a couple of connections. Did you get the 2.1 Digifant harness? The one that connects to the big ECU plug and has the other black box with 2 relays in it?

There is also a small "engine harness" that is separate from the Digifant harness and this is what connects to a round connector. If you got this with the 2.1 then connecting it to the 84 vehicle harness is mostly a matter of matching up exact wire colors. This "engine harness" has things like the oil pressure switch wires, the temp gauge sender wire, etc. Nothing for the fuel injection.

Mark

FreewheelinWesty wrote: ...this is what I had coming from the black box, the connectors wouldn’t match up, and this motor has “stuff” on it that a 2.1 motor has that a 1.9 doesn’t.

im not 100% sure, but i don’t think it’s as simple as a couple simple splices in the engine harness.

can anyone help me with the specific wires that would have to be spliced, and the wires that wouldn’t?

Wed Oct 04, 2017 5:26 pm

Hold on. I think you are missing some of the 84 wiring and that explains a lot of your confusion about the round connectors. The 84 van had only ONE of those round connectors at the wiring box from the vehicle main harness but later vans had TWO of those round connectors from the vehicle main harness. The 84 used the ONE it had for things like rear tail lights, rear turn signals, etc but NOTHING for the engine and the engine wires were just loose single wires. In later vans with 2.1 engines VW added a second round connector just for the engine harness wires that were loose in older vans. They both had almost the same engine wires but later vans put them in a second round connector. I think you are trying to connect the wrong round connectors together because you are missing the 84 rear light harness with it's round connector. The round connector from the 2.1 engine harness has nothing to match up to in the 84 vehicle harness except for loose wires of the SAME COLORS.

Did this 84 have an engine fire?

Mark

Wed Oct 04, 2017 7:18 pm

crazyvwvanman wrote: Hold on. I think you are missing some of the 84 wiring and that explains a lot of your confusion about the round connectors. The 84 van had only ONE of those round connectors at the wiring box from the vehicle main harness but later vans had TWO of those round connectors from the vehicle main harness. The 84 used the ONE it had for things like rear tail lights, rear turn signals, etc but NOTHING for the engine and the engine wires were just loose single wires. In later vans with 2.1 engines VW added a second round connector just for the engine harness wires that were loose in older vans. They both had almost the same engine wires but later vans put them in a second round connector. I think you are trying to connect the wrong round connectors together because you are missing the 84 rear light harness with it's round connector. The round connector from the 2.1 engine harness has nothing to match up to in the 84 vehicle harness except for loose wires of the SAME COLORS.

Did this 84 have an engine fire?

Mark

no engine fires, i took the 1.9 wiring harnesses out

Wed Oct 04, 2017 9:16 pm

When putting L-jet FI into a Bay Window bus that came with carburetors you are only talking about hooking up four wires to get it to work, same with replacing D-jet with L-jet on a 411 or Porsche. I don't think it takes many more wires to do a Digifant swap in an earlier watercooled Vanagon.

I intend to do this same swap in the next couple of weeks.

Wed Oct 04, 2017 9:25 pm

I have both wiring harnesses from both motors, and yes it has the other black box.

crazyvwvanman wrote: Since I have converted 84 vans to 2.1 engine/cooling/Digifant systems I am 100% sure how simple it is with the right parts. You need the Digifant fuel injection harness for your 2.1 engine.

That fuel injection harness is separate from the other wiring except for a couple of connections. Did you get the 2.1 Digifant harness? The one that connects to the big ECU plug and has the other black box with 2 relays in it?

There is also a small "engine harness" that is separate from the Digifant harness and this is what connects to a round connector. If you got this with the 2.1 then connecting it to the 84 vehicle harness is mostly a matter of matching up exact wire colors. This "engine harness" has things like the oil pressure switch wires, the temp gauge sender wire, etc. Nothing for the fuel injection.

Mark

FreewheelinWesty wrote: ...this is what I had coming from the black box, the connectors wouldn’t match up, and this motor has “stuff” on it that a 2.1 motor has that a 1.9 doesn’t.

im not 100% sure, but i don’t think it’s as simple as a couple simple splices in the engine harness.

can anyone help me with the specific wires that would have to be spliced, and the wires that wouldn’t?

Thu Oct 05, 2017 3:14 am

Let us return to basic question #1

Do you have the Bentley with the wiring diagrams?

If you do it is a simple matter of comparing your year wiring with the donor engine year wiring.

The changes are minor and work arounds are easy.

You need zero additional wiring from the fuse panel nor do you need to make changes at the fuse panel, put all of that wiring back in.

If you are running blind without diagrams, you will frustrate yourself.
Take comfort though that VW pretty much keeps wire color the same for a given item over the span of decades.

Dave

Thu Oct 05, 2017 1:23 pm

I do have a Bentley with the wiring diagrams. My mechanic is now putting the whole 1.9 body harness back on the van. He has the new ECU mounted where it should be and the entire harness is installed on the motor and plugged into the the new digifant ECU. Once the 1.9 body harness is back on then we work on splicing it to the 2.1 harness.

Here is what I need to splice from the 2.1 motor harness from an 89’ . any help with the splicing once we get there?

djkeev wrote: Let us return to basic question #1

Do you have the Bentley with the wiring diagrams?

If you do it is a simple matter of comparing your year wiring with the donor engine year wiring.

The changes are minor and work arounds are easy.

You need zero additional wiring from the fuse panel nor do you need to make changes at the fuse panel, put all of that wiring back in.

If you are running blind without diagrams, you will frustrate yourself.
Take comfort though that VW pretty much keeps wire color the same for a given item over the span of decades.

Dave

Fri Oct 06, 2017 8:08 am

There are 7 wires there in that round connector. You need to connect 5 of them to the 84 vehicle harness wires of the same exact color. The yellow isn't used in 84. The brown needs to get attached to a body ground.

blue/black - oil pressure switch 1
yellow/red - coolant temp sender, gauge
blue/green - coolant level sensor
brown - ground for sensor
green - tach signal (from ign coil)
red/black - starter signal (for ECU harness)
yellow - oil pressure switch 2 (not used in 84)

Mark