# 8v swapping... CIS to DIGI II



## sarcastro (Jun 3, 2010)

the low down, I have engine 1.8 , ecu, and harnesses from a 89 golf. ECU sticker says DIGI II
swapping into 81 rabbit with a 1.6 CIS (CIS is shot, disk is bent, and the injectors are gone as well as the motor is siezed) I've searched and there are lots of guides on 16V digi 1 and 16v CIS but nothing on DIGI II, and there are lots of people that say these suck.. well I don't care about that, I have a basically free car, and basically free engine and I want to marry the two. (wife says it has to go, and I'd have better luck selling a car that runs in the winter)

things I have: 
the digi motor is already bolted to into its new home.
a haynes manual that covers both models of VW

I have tested the Fuel pump in the old rabbit and it puts out plenty of PSI to get the job done, so I figure I need to:
1) add a O2 sensor (the digi plug is 3 prong, should I get a cheapo 1 wire or get the one that matches the Golf)
2) swap the coolant flange from the 1.6 to accommodate the rabbit heater
2) divine the pin outs of the chassis part of the wiring (haynes doesn't seem to have a pin out of this)
3) mount the ECU (I am guessing this goes inside?)

4) route the fuel from the driver's side to the passenger side with some high pressure fuel hose? (are there fuel rails that will accommodate this switch easier/cheaper)

5) figure out deleting the A/C pump 

does anyone have pointers or suggestions on this?

thanks!


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## Seax_Smith (Jun 1, 2007)

Digi isn't the greatest system, but it only sucks if you haven't taken the time to learn it. It is its own little creature.

1) the three wire O2 sensor. One wire is the signal wire. the other two are power and ground for the heater/resistror. doesn't matter which is power and which is ground. What does matter is that all the grounds, including the shilding all ground to the head. For power tap the fuel pump coming out of the fuse box. this way you will only be heating the )2 sensor when the car is running. Have down this thre wire upgrades on CIS mark II "GX" cars with no issues.

2) front collant flang will need to be digi, so it can carry the CTS. 2 types: plastic flange, blue 2 wire sensor or Alumionum flange with white single wire system

2 again) wiring wise, you will pretty much need to superimpose the digi engine harness over what is there. There are only a few wires going back to the fuse box, so it shoun't be too bad.

you will need a HAll sender distributor. Hall senders all do the same thing Mark I - Mark III.

3) ECU fir MArk II's mounts in the rain tray right in front of the driver's seat, right up agains the hinge. Ecu carrier slips under 3 pins and is secured by a palstic nut on a stud.

4) fuel wise, oyu will probably better off grabbing the entire fuel delivery system for the Digi. Digi runs at a lower PSI than CIS(E) and I don't know how the FPR will react to the extra pressure.

5) keeping my fingers still on the AC delete.

THese might help:

http://home.comcast.net/~seaxsmith/gti/digifant_tuning.html

http://home.comcast.net/~seaxsmith/gti/z_old_site/digi_pin.html


Hope you can read through my dyslexia.


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## sarcastro (Jun 3, 2010)

1st off , thank you!

2b) the disty (sans cap) is on the engine already, and there is an axillary box mounted to the ecu is this the haII disty?

3) so _*in *_the rain tray not in the passenger compartment?

4) I was thinking I could use a FPR or just an aftermarket fuel pump? so I should try to source a fuel pump and stuff from a


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## Seax_Smith (Jun 1, 2007)

You'll need the digi air box too.... 

1) Digi has its own cold strat thing going on so all the cold start stuff will be coming off the car.

20 ECU is dirvers side of the wipers is the stock location.

4) Fuel Delivery. THere really isn't an easy/cost effective aftermarket soultion for digi... source an intank pump, fuel reservoir, pump. filter et al ad nausium form any digi mark II, basically any 8 valve form late 87 to 92.

If you can find a donor car, take everything including the wiring, and be SURE TO GRAB the fuel res mounting bolts.... the rubber things....

THe distrib..... and hall sender distrib which wioll match the engine will work. Hall senders all do the same job the same way, but come in several slightly different forms. If it is a three contact plug, it will work.

BIG POINT: you will need the "black" distrib cap.... same as the oragnge but has a black shiel around it. be sure it the metal clip seat on the cap grounds to the disrtib body or block or the car wont start.

*W A I T ! ! ! * you can't use the CIS injectors.... digi injectors are pluse controlled..... you need digi injectors/ rail and may/will need (not sure) a DIGI HEAD.


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## sarcastro (Jun 3, 2010)

Gotcha, 

the digi engine is complete including head, injectors, fuel rail and all
the disty has a 3 prong plug so I assume I'm good so im off to find a black disty cap


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## sarcastro (Jun 3, 2010)

*fueling*

I think I can just adapt the current fueling setup with an adjustable FPR and some high pressure hose and AN fittings.. 

any thoughts on this?


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## Seax_Smith (Jun 1, 2007)

sarcastro said:


> I think I can just adapt the current fueling setup with an adjustable FPR and some high pressure hose and AN fittings..
> 
> any thoughts on this?


 
Digi does require slightly less fuel pressure than CIS(E), so you may be onto something..... all the fuel pressure specs are in the bently, so if you can deliver the volume at the correct pressure range, you should be good to go. 

So you are spitting a bit more fuel back into the tank. Not like the injectors are going to care as long as they are getting what they need from the rail. THink of it a "positive fuel cycling" to insure any fuel additive stay well mixed in any condensation is equally dispersed!


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## sarcastro (Jun 3, 2010)

awesome, I was thinking something like this: 

http://cgi.ebay.com/ebaymotors/PSI-...ptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories 

but I may just go with this: 

http://www.jegs.com/i/Quick+Fuel/793/30-803/10002/-1 

as it has threaded inserts


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## Seax_Smith (Jun 1, 2007)

It's all baout the right volume at the right pressure..... doesn't matter how you get it there so long as you can sustain it.


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## sarcastro (Jun 3, 2010)

book says 35PSI the cis pump does 85... I think I can do this! 

thanks again for all the help!


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## Seax_Smith (Jun 1, 2007)

so what are you coming up with for options? 

started to look into this a copuple of times, but always eneded up side tracked.


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## Glegor (Mar 31, 2008)

sarcastro said:


> book says 35PSI the cis pump does 85... I think I can do this!
> 
> thanks again for all the help!


 usually, the CIS pumps do closer to 100 psi.. 

its gonna be way too much pump for what your trying to do. digifant only needs 44 psi system pressure when its wide open.. 

and if you want to do an easy digi swap into your mk1, find a late mk1 cabrio.. they were digi.


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## sarcastro (Jun 3, 2010)

if its pumping close to 100 it really wont matter right, as that's what the return line is. 

Smith, I was looking at one of those cheap ebay regulators, as long as it had a return line .. and if I burn out a CIS pump, then I'll just replace it with a regular 45PSI framerail pump... the point here is to see if I can do it. 

I already have the digi motor, just no pump ..


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## WaterWheels (Aug 14, 2005)

sarcastro said:


> if its pumping close to 100 it really wont matter right, as that's what the return line is.


 I would get the correct pressure pump to prevent any possible regulator damage and/or injector damage, over feuling or what not. Yes it has a return line from the regulator but I think that more than twice the amount of system pressure is going to overpower things. The regulator being held wide open always could wear it out faster and the extra pressure at the injectors could do who knows what for sure.


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## sarcastro (Jun 3, 2010)

alright' I'll put out a search for a digi pump as well...


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## sarcastro (Jun 3, 2010)

got the pump,doing the install tonight!


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## Glegor (Mar 31, 2008)

Seax_Smith said:


> Digi does require slightly less fuel pressure than CIS(E), so you may be onto something..... all the fuel pressure specs are in the bently, so if you can deliver the volume at the correct pressure range, you should be good to go.
> 
> So you are spitting a bit more fuel back into the tank. Not like the injectors are going to care as long as they are getting what they need from the rail. THink of it a "positive fuel cycling" to insure any fuel additive stay well mixed in any condensation is equally dispersed!


 the CIS pump operates upwards of 100 psi.. 

the digi pump does 45 psi maybe.. 

digi fuel systems have all there hose connections clamped.. 

CIS had to use screw fittings.. 

why dont you just find a late mk1 Cabby and take all the mk1/digi2 pieces you need.. 

those were the only mk1s to come factory with digi2.. 

be careful, that digi2 is GOING to give you HEADACHES.. and fits of RAGE.. 

cis is robust, and almost never gives problems.. 

CIS is really an awesome fuel system, for what it is..


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## sarcastro (Jun 3, 2010)

whole thing went sideways, nothing worked, headaches backaches, 


does anyone know if a 1.6 intake will work on a 1.8 digi motor?

also does anyone know where I Can get CIS injector cups the plastic ones not the brass ones


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