Here is the car


Here is the enclosure that holds the megasquirt board in the engine compartment


Here is the connector i modified to fit my enclosure. It will form a watertight seal with a silicone gasket against the enclosure, hopefully =)


The wires were potted into the connector using a silocone glue.


Here is how the connector fits into the enclosure..


Here is a picture of my EDIS setup. I remade the crank pulley in aluminum to allow the mounting of the EDIS gear, and to cut down weight.


Here is the EDIS gear along with the sensor mounted on the car.. Not a quick job!!!


Here is a top view showing the EDIS gear and the coil pack in the upper left corner. How cool is that? no distributor!!! (I think you can use an oil pump, drive gear, and distributor block off plate from a 16v motor and eliminate the distributor all together. The dissy on the 16v is on the head but it uses the same block as the 8v so the location on the block has been plugged from the factory.)


This is the dash panel i machined to hold the LCD, Keyboard jack, LED's and places for 10 buttons



Finally its installed in the dash! Well kinda. Mounting it flat to the dash like i had intended makes it kinda hard to see while driving.. so i'm going to have to mount it on a slant, hence the duck tape for now. I also bought the wrong ps/2 jack, so the keyboard connection will have to wait.. For now it is hard wired.


Here is a picture of the relay / fuse panel i made. Maybe we should consider something like this as a side item? it makes life alot easier (good idea. We should decide about size, how it fits into Alubos besides v3, or another box, and exact PCB. MarcellGal?)


Update 03/07/04

EDIS is running in limp mode!! i can't believe how smooth it runs compared to a distributor..

I made a small mistake with the mounting of the EDIS gear. I had put the missing tooth 90 before the sensor when the engine was at TBC. It needs to be 90 degrees ahead of the sensor. Very confusing! but i swapped the gear around, and it started right up..

Also, the polarity of the VR sensor is important..

Next step is to swap over the throttle body to one that has a TPS sensor. (Which i seemed to have lost in my recent move)

Then get MSAVR to controll the advance of the ignition.. ONce that is up, I'll move onto swapping over the mechanical injectors to EFI

Update 03/14/04

Alot more work done this week.. All the sensors are up and working except for MAT (not sure what is going on there, didn't have time to check it out)

EDIS is complete, and is running with advance. The RPM jumps now and then, but other than that it is great. RPM jumping is not good at all. Can you detail - or draw, or point to a drawing similar to - your connection? There are 3 usual ways to connect PIP to IC3 on GenBoard v2.2. 2 involves the opto (PIP is connected either the cathode or anode side of the infraLED inside the optocoupler), or with a 2..20k resistor to IC3 - in that case you don't want a pullup on IC3 to +VCC, but you want a protection diode: either simple diode to VCC or 5v1 zener to GND.

as marcell recommended in the email list, this is how i modified the EDIS input signal

I used a voltage divder circuit, with a 20k resistor going between PIP and the AVR input pin. Then from the input pin, I put 10k to ground. I also placed a 100nF cap in parralel with the 10k to create a filter.

The 100nF is heckofalot. Delay introduced is in the range of 100nF * 6.6k = 660usec (6.6k is the equivalent of the 20k and 10k divider). Consider cutting it to 1..10nF. (that is for EDIS, where the exact timing of signal is not very important. For a HALL => DummyIgnition I would recommend max 1nF).

This circuit cuts the input going to the AVR to around 4 volts. I then placed a diode pointing towards VCC from the AVR pin, which i believe prevents the AVR from somehow being powered indirectly...



20k resistor


AVR IC3pin --- diode >|--- VCC


10k resistor + 100nF Cap in ||



LCD display is installed in the dash, and the keyboard is hardwired for now..

Next is to install the new injectors and fuel rail.. I'm also burning PC board to mount the fuse panel and relay

Update 03/25/04

I'm only hours away from a full startup.. Ran into a couple snags. Turns out the zener diode for the MAT sensor was burned out.. I replaced this, and it now reads the correct temp. Before that, it read 170 all the time.

I plumbed all the fuel system, and did a pressure check.. Turns out my injectors are leaking slighly. So i've just ordered a replacement set.. I had bought a used set that came with my fuel rail, and they must have been no good.

I also just got an ITG filter, which will be going into a custom cold air system

Update March 29 2004

So I got the new injectors in, and the car fired right up!!

I didn't have alot of time to tune this weekend, but it seems like it is going to be more of a task than i anticipated..

Things I need to do:

-Buy a Wide Band 02 meter... Too bad i'm not running v3

-Put some sort of timing degree marks on the pully so i can double check advance

-Sort out issues with temp sensors

-Look at a better EDIS input circuit per Marcells advice..

-Double check my fuel pressure

It seems as though the temp sensors (VW 84 GTI) are railing out at low and high temps.. And the resolution isn't that good at higher temps...

I took 16 points along the sensor, and here are 3 of them.. It seems as though the GM sensor is much different. Would changing the 2490 ohm R help?

32 degree F = 2800 OHm

80 degree F = 730 ohm

32 degree F = 124 ohm

Update March 30, 2004

I had a little bit of time to play with msavr yesterday... heres what i discovered.. hopefully it will help someone else =)

the reason I was running so rich was:

you need to set the required fuel for the engine (which i knew).. which is based on injector size and engine size...

it then divideds this number by the number of injections per cycle and whether or not you alternate or simulatiosly inject all cylinders...

required fuel pretty much sets your idle mixture...

what i did wrong was have it set to 4 injections per cycle.. so the required fuel was devided from 14ms to like 3ms per injeciton... the injector couldn't handle that physically so it's metering was way off.. leading me to think my fuel pressure was too high or something....

so i dropped it to 2 pulses per cycle.. 1 pulse makes it kinda lumpy... i also set it to alternate injector banks....

it runs alot smoother and leaner now....

but.. with the alternate injection.. should it be cylinder 1+3 and 2+4? or does that not matter since i'm injecting twice a cycle... i have the injectors wired 1+2 and 3+4

Next stumbling block was the temp sensors... i was confused why the LCD displayed the correct temp with the recalibrated sensors... but megatune didn't...

turns out you need to put your files in the megatune config directory... it reads the raw sensor levels from msavr....

I think i still need to fine tune the temp sensors.. the resolution at high temps is crap.

Update March 30, 2004 PART 2

So i decided to make a graph of how changing the voltage divider resistor from 2490 to 100, 1000 and 5000..

It appears as though using a 100 ohm resistor for coolant temp will give me 10 more data points between 215 and 150 degrees F.

However it hurts the lower temps, so i will keep the 2490 resistor for the air temp... which is in the linear range of the sensor.

I generated these curves using the therm.c program, with 16 data points

Here is a PDF of the Graph

[Coolant Temp Sensor for 1984 GTI]

Update May 3rd

So i gave up trying to use the stock vw temp sensor. i adapted the coolant fitting to use the GM sensor, and recompiled the firmware with the proper thermfactor. Finally my msavr says i'm running at a realistic temp, and the fan works much better..

I also realized that i didn't have the option for software pcm compiled in, and that was ONE reason the idle air valve wasn't working.. the other reason was that the valve was burnt out.. So now i'm waiting on that..

Once that is on, i'm going to drive the hell out of this car!!