This page describes in detail what is required to swap EFI into an early A1 vw. specifically 8v and 16v sciroccos.

The wiring diagrams will vary a bit if doing the swap into a golf mk1, rabbit, or cabby.

WhatEverYouDoYouDoItAtYourOwnRisk applies as always.


While it might seem imposing at first swapping to EFI in an early VW is very easy and most or the stock wiring harness can be maintained. There will be different degrees of conversion ie. a simple swap into an 8v, to a turbo swap or ITB conversion. The basics of the EFI swap remain constant, tuning is what is different.


Remaining items

Now your left with a motor with the Ignition system still hooked up.

If you have a knock box it's still in if not don't worry about it.

So step 1:

Fuel Delivery system:

The nice thing about the 8v is that you don't incur extra cost for a fuel pressure regulator (FPR) it's built into the fuel rail [ insert pic ], same for the 1.8T fuel rail [ insert pic ]. with a 16v your going to need a FPR you can either go with one that mounts on your fuel rail or one that mounts on the firewall.

The Plumbing circuit your trying to build looks like

Fuel Tank -> ( Transfer Pump) -> CIS Fuel pump -> Fuel Filter -> Fuel rail -> FPR -> Return to fuel tank [ Make a better pic ]

You'll also need Fuel Injectors contact for your Fuel Injector needs.

So now your wondering:

I've got the Fuel rail, fuel injectors, fuel filter, How do I connect them? You goto the Parker store and have the appropriate Stainless steel braided teflon lines made. Specific lines for specific cars will be constructed and have thier dimensions and types listed here later, It will start with the 8v cars, because its cheaper, unless you want to send me a ross fuel rail free.

and all of this will BOLT into place on your car.

This essentially describes the replacement of the Mechanical portion of the swap from mechanical Fuel Injectors to Electrical Fuel Injectors. ( If you start with a digifant/motronic car this is already done for you by Volkswagen.)

Electrical Plumbing / Circuit Modification For the Fuel Circulation system

This is REALLY easy.

Assuming car is at least CIS-Lambda ( has an o2 sensor )

A1 without Transfer pump

A1 with transfer pump

A1 with transfer pump & Heated 02 Sensor (16v)

ASSUMPTION Motronic & Digifant cars are similar to transfer & heated 02

Now you've got the fuel circulating is the system, it is a good time to check it for leaks.

Disconnect the hall sender, or if its a piece of junk disconnect the connector to the ignition module. Thats the small one under the hood on the piece of alumimum (heatsink). This will keep it from building any spark. Also short out the big wire from the coil.

GO GET A FIRE EXTINQUISHER for FUEL ie. PKP You are working with high pressure fuel.

GO GET A FIRE EXTINQUISHER for FUEL ie. PKP You are working with high pressure fuel.

pressurized fuel fed fire is not pretty or safe.. CO2 extigushers will NOT put out a fuel fire.

Hook the battery back up.

and have an assistant jumper the fuel pump as per bentley manual. If any leaks are spotted STOP and fix them immediately, clean up the fuel completely, and try again.

now that there is fuel flowing in the system, check everywhere for leaks.

you should hear the fuel moving back into the fuel tank. run this for as long as it take for you to be confident there are no fuel leaks. Dont worry, this is what the car does the whole time its running.

Now you get to worry about hooking up the GenBoard, hopefully you werent too cheap and bought the fully assmebled version, if not go to the Manual and put it together.

Inputs for the GenBoard v3

Outputs from the GenBoard

Still controlled by stock wiring harness


picture and ID of [ Temp sensors]

Notes of Vanagon Temp Sensor [ Curves]

Copy of the L-jet [ manual] pg8 has the curve for the clyn head temp sensor and

[ L-Jetronic Manual]

[ K-Jet & KE-Jet Manual]

Ingition [Article (pdf)] Its about mechanical advance, but theory still applies

[ L-Jet page about MAF plate]

[ MAF plate mods]

Alternative Triggers

here is a [ picture] of Derricks crank trigger setup from looking at the senor. It is probably a VR sensor.

TODO: let's decide how this guide fits into the PlugAndPlayDigifant, PlugAndPlayEEC ... series and move the page. The question I cannot answer is if it applies to all CIS (eg. Mercedes and US beasts? I guess not!). Maybe rename to PlugAndPlayVagCis? or something...