Mexican Beetle 1600i

Fuel Injection System

Ignition Timing

 

Version 1.00

 

Phil Ade 2005

Table of Contents

 1.0 Introduction     

 1.1 Tools Required 

 1.2 Prerequisites  

 2.0 Setting the Timing on a 1600i Engine 

 2.1 Connecting up the Diagnostics Kit to the Car

 2.2 Using the Diagnostics Kit 

 2.3 Ignition Timing 

 2.4 What to do if the ECU went into permanent emergency mode  

 3.0 Acknowledgements  

 3.1 Finally….    

1.0  Introduction

The ignition part of the Digifant fuel injection system is generally (automatically) controlled by the Digifant ECU its self.  It consists of an ignition transformer (rather than an ignition coil), a distributor and a vacuum unit which is part of the ECU its self.

The distributor its self contains a rotating magnet (fixed to it’s shaft), hall sensor (instead of contact breaker points) and a rotor arm at the top of it’s shaft.

This document is intended to cover the correct method of adjusting the ignition timing of a 1600i engine.

1.1 Tools Required

The following tools are required to carry out ignition timing on a 1600i engine:-
 

1.2 Prerequisites

The following must be satisfied before you even attempt to set the ignition timing of a 1600i engine.

 

IMPORTANT PLEASE READ THIS BEFORE YOU START!!

Please note that it would be absolutely futile if you try to set the ignition timing without a VAG or VAG-COM fault code reader/programmer. 

If you do so, you will seriously risk putting your car’s ECU into emergency mode permanently.  This will cause the engine to barely run at all, use lots of petrol and it will get hot very quickly !!

2.0 Setting the Timing on a 1600i Engine

The process of setting the timing of a 1600i engine will now be explained in separate sub-sections:-

2.1 Connecting up the Diagnostics Kit to the Car

The diagnostic socket on a mexican beetle 1600i is located in the top left hand side of the rear engine compartment, which is shown in the photo below:-

Disconnect this socket from it’s dummy plug by pressing the metal clip on both sides of the socket and pull off the socket away from it.  You can now get at the diagnostic socket which is shown below:-

Now connect up your diagnostics kit to the diagnostics socket.  I will be referring to my VAG 1552 fault code reader throughout this document but the same applies to other diagnostic kits as well.  The photo below shows my home-made cable being connected to my car’s diagnostics socket:-

Make sure that you have connected it the correct way round, where the following applies to the diagnostics socket:-

 
Wire Colour Purpose
Red + 12V
Brown 0V (Ground)
Grey/White  K-Line Data (do not short this wire to +12V !!)

After you have ensured that you have connected up your diagnostics cable correctly to the 1600i’s diagnostic socket, connect up the other end of your diagnostics cable to your diagnostics test kit.

My home-made VAG 1552 to mexican beetle cable is shown on the next page.  I have wired an LED inside the 5 pin 270° bayonet  Tuschel plug to indicate that +12V and 0V have been connected the correct way round.  This is generally a fail-safe way to protect the K-Line of my VAG 1552.

 

Anyway to those of you who do not know what a VAG 1552 looks like, here’s a picture of my one below:-

2.2 Using the Diagnostics Kit

Before you can use your diagnostics kit to do anything on a 1600i, you must start up it’s engine and wait for at least 6 seconds.

Now type in command 01 – Engine Electronics on the VAG 1552 or equivalent and confirm by pressing the Q key:-

The VAG 1552 will now interrogate the ECU to find out it’s part number and software version number which would typically look like the photo below (in this case I have the D version of the ECU).  This would normally take about 5 to 10 seconds, possibly longer in the case of the VAG-COM but I cannot be certain.

The VAG 1552 will now go to the enter function screen.  Now enter the command 08 – Read Measuring Value Block followed by the Q key:-

 

The VAG 1552 will now ask for a Measuring Value Block number, enter 001 followed by the Q key:-

 

The VAG 1552 will now display the engine temperature in °C.  Now leave the engine running until the oil temperature has reached at least 80°C:-

After the engine has reached operating temperature, you should now check the ECU for faults.  Press the C key to exit the Read Measuring Value Block function.

Now check the ECU to ensure that there are no faults.  To do this enter the command 02 – Interrogate Fault Memory and press the Q key:-

 

If there are no faults within the ECU, the following message will be displayed:-

If no faults were found then press the -> key to go back to the commands menu, otherwise write down what faults were found and correct them before you continue.

Now enter the command 06 – End Output, press the Q key and switch off the engine.

2.3 Ignition Timing

Now connect up the battery extender from the car’s battery its self.  Here’s a photo of my home made one which is particularly useful since my timing gun’s power leads are not long enough:-

Now connect up the timing gun to the battery extender and it’s inductive pickup to cylinder 1’s spark plug lead:-

Now adjust the timing gun’s advance control (which will help you to set the 1600i’s timing to 6° BTDC according to VW’s Digifant Injection and Ignition System booklet) to 6° BTDC:-

Notes: Be careful when you are adjusting the ignition timing if you have a 1600i engine with Manfred’s tuning chip.  Make sure that you don’t accidentally cause the engine to knock by adjusting the ignition timing too far !!

On the 1600i website it mentions that the timing could  be set to additonal 3° BTDC so I will guess that both the VW documentation and  the 1600i website are correct.

Now start up the engine and increase the engine speed to 1500 ± 200 RPM.  Use your diagnostics kit by measuring it’s engine speed.  In the case of the VAG 1552 use the following commands:-

Use a wedge between the accelerator lever on it’s air intake and the idle end-stop it’s self to maintain that engine speed.

Please note that the whole timing process must be completed in less than 30 seconds from here on to avoid the ECU from going into permanent emergency mode.  If it does, it can simply be reset by clearing the fault memory, which will be explained later.


Now locate the engine oil temperature sensor plug (next to cylinder no. 4) which is shown below:-

Now have your ratchet, short extension bar and 10mm socket nearby because you will need them very quickly indeed !

Now press the clips on both sides of the engine oil temperature sensor plug and pull it off.  Immediately pull the throttle lever back to increase the engine speed back up to 1500 RPM and hold it there !  The engine at this point will barely run at all.

Now immediately aim the timing gun at the lower crankshaft pulley and check to see if the notch lines up with the crankcase’s centre-line:-

If the timing is incorrect then it can be adjusted by slackening the 10mm clamp nut on the distributor and rotating it:-

After the ignition timing has been correctly set, immediately tighten up the clamp nut and re-connect the engine oil temperature sensor.  Now let go of the accelerator lever immediately !!

If the ECU has not gone into emergency mode the engine will now run normally.

2.4 What to do if the ECU went into permanent emergency mode

If the ECU has logged that G27 (the engine oil temperature sensor) has become faulty, then the ECU will go into permanent emergency mode.  If you do not have a diagnostics kit then you are pretty much in serious trouble at this point and should have read section 1.1 !!

To get the ECU out of emergency mode, do the following:-
 

3.0 Acknowledgements

I would like to thank following for their help:-

ErWin – VW Service Department – Technical Information for providing downloadable (paid for and time limited sealed PDFs) documentation on various aspects of the 1600i engine.

Manfred Graf for his great website http://www.1600i.de/ which has lots of very useful documentation and tips. It has helped me a lot with various issues with my own 1600i beetle and I would really not know what to do without it.  If anyone has a problem with his or her 1600i beetle, then this is the website to go to.

I would also like to thank him for all of his help too with his CDs in exchange for a copy of my printed out VW documentation and for giving me various hints and tips too via email.  I would very highly recommend getting WinETKA since it will allow you to cross-reference 1600i parts with other VW models, thus making it very easy to order 1600i parts from almost anywhere.

I would also like to thank everyone who has participated his 1600i website too, everyone has done a great job.

3.1 Finally….

I have written this document as a way of saying thankyou to Manfred for all of his help. I thought that I could help others too by writing (in my own words) the english documentation of the ignition timing for the 1600i beetle engine.