# Megasquirt Questions & Opinions 2.0 16V



## 16ValveInside (Nov 20, 2004)

OK guys, need your help. I'm going with Megasquirt. This is a unmolested 91 GTI 8V car. I just rebuilt and installed a 16V 2.0 engine (with a 3.94 R&P trans from broke.com ) and I'm going NA. I want megasquirt to control fuel & spark. Stock coil and stock distributer. 

I want to keep this as simple, basic, cheap, as possible. Yes, I'm reading through the MS stuff, maunals, threads, etc. and the more I read the more I realize I don't know. This will be the 1st attempt at a shopping list, and hopefully with your help it will be revised to what I really need, and maybe it will help others with a similar build along the way. I do not plan on FI.










My Current List: - *updated 09/03/12*
going to buy the ECU custom built versus building my own

Processor MS1 
Main Board V3.0
Embedded Code - MSx/extra code 
Tuning Software - TunerStudio?
Relay Board - do I really need this? - *Not using a relay board*
12' long Wiring Bundle DIY Auto Tune - *ordered from DIY Auto Tune*

Wideband O2 sensor and gauge combo
Fuel Rail - *finally found a Ross Machine Racing 16V rail *
Pressure regulator - *using Bosch 3.5 bar*
Passat T/Body with TPS
Intake tube - *Will buy one off Ebay, heard a short runner intake for a 92 Civic works*

Fuel Injectors - *using Bosch 0-280-155-868 - ordered EV1 connectors from DIY Auto tune*

Sensors
(open element GM sensors?) *ordered GM open element IAT Sensor w/connector - DIY Auto Tune*
Saturn Coolant Temp Sensor that screws directly into head and Intake air temp. 

What about Idle control Valve?

I know I'll need other misc. items as well but let me know what you think so far.


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## bomberbob (Sep 19, 2004)

You are missing stuff, injectors, the "bung" you need to screw into the intake manifold to mate up to the injectors, etc. I think you have the main items.
I run without an idle control valve. Others may have a difference of opinion. I do have a little more trouble in the morning, but I can't tell if its the lack of the valve, or the fuel (E85). I do have a nuisance oscillation where the RPM hunts up and down a little bit, but it doesn't bother me that much. I removed mine and capped off the spot where it and the 5th injector went, so there is less to go wrong now.


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## 16ValveInside (Nov 20, 2004)

bomberbob said:


> You are missing stuff, injectors, the "bung" you need to screw into the intake manifold to mate up to the injectors, etc. I think you have the main items.
> I run without an idle control valve. Others may have a difference of opinion. I do have a little more trouble in the morning, but I can't tell if its the lack of the valve, or the fuel (E85). I do have a nuisance oscillation where the RPM hunts up and down a little bit, but it doesn't bother me that much. I removed mine and capped off the spot where it and the 5th injector went, so there is less to go wrong now.


I've got the injector cups/bungs on the way from german auto parts, injectors I have not determined which ones to get yet, been looking at prices. I would love to be able to get away without a Idle Control Valve.


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## 16ValveInside (Nov 20, 2004)

And since I'm not going FI, is this the correct IAT Sensor to use - (From diyautotune website)

Closed Element Intake Air Temp Sensor (IAT) on naturally aspirated vehicles. These are the proper GM-style sensors for use with the MegaSquirt line of ECUs and include a 6" wire pig-tail with weatherproof connector.


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## need_a_VR6 (May 19, 1999)

I just use the stock VW ones, but that will work as well. I use open element ones on everything where I'm given a choice. They respond better to temp changes and are useful for doing IAT timing corrections if that's important to you.


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## Prof315 (Jan 5, 2009)

Some type of idle valve is nice but not essential. 2wire G60, OBD1 ABA and VR6 valves all work quite well with MS.


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## ValveCoverGasket (Mar 20, 2002)

16ValveInside said:


> I want to keep this as simple, basic, cheap, as possible.


 based on this id go with a v2.2, ms1-e and use a bosch ICM to fire the coil. done and done. super cheap too, especially if decide to build it yourself...


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## 16ValveInside (Nov 20, 2004)

ValveCoverGasket said:


> based on this id go with a v2.2, ms1-e and use a bosch ICM to fire the coil. done and done. super cheap too, especially if decide to build it yourself...


 ok, lets move this up to the next level, I'd like MS to fire the coil, basically control fuel & spark, and eliminate the need for the Bosch ICM


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## Prof315 (Jan 5, 2009)

16ValveInside said:


> ok, lets move this up to the next level, I'd like MS to fire the coil, basically control fuel & spark, and eliminate the need for the Bosch ICM


 Very easily done. A V3.0 kit includes a Bosch BIP373 IGBT. They are just about unkillable.


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## need_a_VR6 (May 19, 1999)

Prof315 said:


> They are just about unkillable.


 I've tried to smoke them on purpose with no luck:thumbup:


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## ValveCoverGasket (Mar 20, 2002)

16ValveInside said:


> ok, lets move this up to the next level, I'd like MS to fire the coil, basically control fuel & spark, and eliminate the need for the Bosch ICM


 then what the other guys mentioned... v3 ms1-e :thumbup:


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## 16ValveInside (Nov 20, 2004)

ValveCoverGasket said:


> then what the other guys mentioned... v3 ms1-e :thumbup:


 v3 ms1-e it is then. 

Next is the relay board. I really don't want to use one, I'm thinking less clutter and much simpler, but I do understand that I will have to add at least 2 relays. 

02 realy for wideband, and Main/ECU relay. This is a 91 8V car so I should be able to use to original fuel pump relay, correct?


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## mk1vw (Oct 17, 2007)

The digi ecu has it's own relay; use it for the MS power. much cleaner. 
IMO you don't need the relay board.


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## ValveCoverGasket (Mar 20, 2002)

you can use the stock ecu power wiring to power the ms, and reuse the factory fuel pump relay. thats what i do anytime im wiring an ms into a car with a stock harness, no need for the relay board... :thumbup:


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## need_a_VR6 (May 19, 1999)

The only times I've ever used the relay board were for installs that weren't EFI to begin with. One was a Olds 442 the other was an engine dyno


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## tchampag (Feb 11, 2005)

threadjack: so if I've got a cis-e 16V I don't need the relay board? Or is this only in respect to digifant. I understand about the fuel pump relay, but what about power in my situation?


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## ValveCoverGasket (Mar 20, 2002)

i wouldnt use one on a cis-e car either...


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## mk1vw (Oct 17, 2007)

i don't like the screw-down terminals on the relay board. looks like a radio shack project. 
more failure points.


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## 16ValveInside (Nov 20, 2004)

need_a_VR6 said:


> I just use the stock VW ones, but that will work as well. I use open element ones on everything where I'm given a choice. They respond better to temp changes and are useful for doing IAT timing corrections if that's important to you.


So is it best to use the stock vw sensors for IAT and Coolant Temp, and if so do just use the stock 2.0 16V CTS? And which VW IAT sensor would be best?


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## ValveCoverGasket (Mar 20, 2002)

my favorite combo is the blue digi cts if youve got an 8v, or the white screw in cts if youve got a 16v, and the GM IAT


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## 16ValveInside (Nov 20, 2004)

couple of questions for the megasquirt pros, I need to order some parts. Looking at DIY Autotune website: 

I'm thinking that the 8ft megasquirt harness should be long enough, dont see any need for the 12ft harness, do you agree? 

I need EV1 injector pigtails, best to get those from DIY as well? 

and I need a coolant temp sensor that screws into the stock location on a 16V, VW, or are you guys using a GM sensor that fits?


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## need_a_VR6 (May 19, 1999)

The only gm one thats direct is the Saturn.

Abf/aba side flange and the aba sensor is what I use.


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## 16ValveInside (Nov 20, 2004)

need_a_VR6 said:


> The only gm one thats direct is the Saturn.
> 
> Abf/aba side flange and the aba sensor is what I use.


 thanks, then I'll just use the saturn sensor 

do you use the 8ft harness?


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## mk1vw (Oct 17, 2007)

looks like this project was on hold for a little while. 
if so, drain the gas tank if not already empty.


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## need_a_VR6 (May 19, 1999)

I usually use 10'-12'. 8 will work but depends on harness route and ecu location.


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## 16ValveInside (Nov 20, 2004)

mk1vw said:


> looks like this project was on hold for a little while.
> if so, drain the gas tank if not already empty.


 good call, I already pulled the tank out, drained and cleaned and reinstalled


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## redrbt2.5 (May 11, 2009)

any progress? I'm trying to learn about megasquirt and I'm liking your thread:thumbup:


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