VW Megasquirt Forum

Ok I just purchased my first Megasquirt kit. I was actually wondering
if I have purchased all the correct stuff. Here is a list of what I have purchased
so far if you guys can suggest anything else I may need please post up.

1 x MegaSquirt-I Programmable EFI System PCB3.0 - UnAssembled Kit
1 x MegaSquirt Stimulator / DIYPNP Power Supply
1 x JimStim v1.4 MegaSquirt Stimulator w/ Wheel Simulator -Unassembled
1 x Jumper 10-Pack
1 x PCBv3 and v2.2 -- Boost Control Mod-Kit
1 x PCBv3 and v2.2 -- Relay Control 'ModKit' (VTEC, TVIS, Fans
1 x MegaSquirt Tuning Cable (DB9 Straight Thru)

I have not purchased any wiring yet because I have not figured out how I am going
to wire my car up. So I know I need that.
Thanks
Reed

What car will this be installed on? The kit only comes with 1 BIP373 coil drivers, so if you need to drive more than 1 coil you will need to order more drivers. Depending on the car, you can also power the coils ignition module with pull up resistors off of the LEDs and you wont need BIP373 drivers. You may need some components to built a tach driving circuit as well. Tell us what car it is for and we can tell you how to build a tach circuit for it, and what else you will need for the ignition etc. A TIP120 or TIP122 is nice to install as well to drive a bosch PWM idle valve.

Sorry forgot to tell the car its going in..
91 GTI OBD1 VR6
I am putting a turbo on the car that is why I have decided to go with megasquirt

I do have a couple of questions already....
should I go ahead and buy the Bosch PWM idle valve? I was up in the air on this one

Second, how do you guys wire the kit up. Do I wire it up to my fuesbox or do build a harness
and wire up all the injectors, coolant sensor, o2 sensor, etc.... all separately and then let my fusebox
run all the other BS like my lights and other little things.

I know I will have more questions but will ask them as they come up
Thanks

Bump, updated the car info to make answering my question easier

The easiest way to wire it up is to get the stock wiring harness. I see that it is a swap into a 91 GTI. If the swap came from an OBD1 MK3 VR6, then I would get the complete wiring harness from the engine to the fusebox just like you would use for dong the swap with the stock ecu. Once you have the stock wiring installed you can just simply tap into the stock 68 pin ecu connector, or cut the ecu connector and run the wires into the car and wire them to megasquirt. The first option would be the best because your would be able to switch back and fourth between the megasquirt and the stock ecu. Paul has a good writeup on both the dizzy vr6, and the coilpack vr6 here:

Dizzy writeup:
http://forums.vwvortex.com/zerothread?id=3359198

Coilpack writeup:
http://forums.vwvortex.com/zerothread?id=4261092

For the dizzy vr6, you will need one BIP373 coil driver, or you can use a 1k ohm pullup resistor from D14and use the stock coil and coil module. For a coilpack vr6, you will need either 3 BIP373 coil drivers, or you can use 3 1k ohm pullup resistors off of D14 to run the stock coilpack via the stock ignition module. Pictures of both are below:

Pull up resistor circuit: (Use a 1k ohm resistor where the picture shows a 750)

similar to this circuit in the ms-extra manual: http://www.msextra.com/doc/ms1extra/MS_Extra_Ignition_Hardware_Manual.htm#bosch



BIP373 Wiring:

http://www.msextra.com/doc/ms1extra/MS_Extra_Ignition_Hardware_Manual.htm#mulitcoil




I would also do the idle valve when you install everything else so you wont have to go back and do it later. The instructions for installing a bosch PWM idle valve are here:

http://www.msextra.com/doc/ms1extra/MS_Extra_Hardware_Manual.htm#Fidle

The stock coil assembly has a built in driver, both on distro and coilpack cars. Skip the bip and use the LED circuit with a 1k pullup and save the BIP(s) for rainy day.

I agree on the idle valve, the mods are easy and they work well for the 2 wire on OBD1.