How to - MegaSquirt on the 1.8t

**JK35** · 07-31-2009 01:31 PM

crank sensor, cam sensor and vehicle speed sensor (VSS)
have me stumped.

The crank sensor has 3 wires, ground, 1.6v and 1.6v. the two 1.6v wires appear to be the same thing...
Is this a VR sensor? does it trigger on rising or falling edge? how do you configure for the 60-2 wheel?

the cam sensor, a single window hall, I have determined the 3 wires to be 5v, 12v/0v sensor signal, and sensor ground.
But is this triggered on rising or falling edge?

Last, I found a VSS on the drivers side of the transmission. it has only 2 wires to it. one a ground, the other an 8v/0v sensor signal that switches from 8v to 0v 4 times for each revolution of the axle. what kind of sensor is this? it can't be a hall, because there is only 2 wires, right? is it a VR sensor of some kind? also, does anyone know if it is rising or falling edge triggered?

Has anyone determined the TPS pinout for stock TB and also for it's idle control? It is a stepper motor idle control right? which idle pairs go to which pins on the stock TB connector?

**pac1085** · 08-04-2009 07:29 AM

No clue about the hall sensor since I don't have it hooked up. I also don't remember the wiring on the VR sensor since I haven't touched it since 2007.

As far as the TPS pinout, there's a link in my first post to the pinouts:
http://rush.smolly.nl/changes/change4_2.htm

As far as I know, no one has got the built in idle motor working on any standalone. It's not a stepper motor, it's some sort of weird PWM.

**Kyle H** · 08-09-2009 10:54 PM

You guys need to get to work on this so that I'll have a base file to use when I do MS on my car.

**JK35** · 08-11-2009 07:21 AM

Ummm... yeah. there are quite a few Megasquirted cars, and the "base tuning" you refer to is readily available, although there is no such thing as simply downloading someone elses tuning, uploading it into your own tuning software/vehicle, and expecting any good results.
Not trying to be a dick, but that comment is a perfect reason you should NOT even consider Megasquirt.

Megamanual and the Megasquirt forums are a good place to study before jumping into Megasquirt.

**Side-Step** · 08-12-2009 03:09 PM

I'm still trying to figure out how to use the older idle control, but was wondering what others are using to get there Audi's to idle or not cut off. My wife is getting upset with me because of this.

**pac1085** · 08-13-2009 05:49 AM

What do you mean by 'older idle control'?

I haven't done it yet, but I decided I'm just going to buy a bosch pwm iac valve and use that.

**4bagels** · 08-13-2009 06:06 AM

Originally Posted by pac1085

What do you mean by 'older idle control'?

I haven't done it yet, but I decided I'm just going to buy a bosch pwm iac valve and use that.

If I understand the basics of it correctly, it's got a kooky motor that physically opens the throttle blade slightly to control the idle, you can actually feel it with your foot on the throttle when it adjusts for the A/C going on and off. It also has 2 TPS potentiometers, one which is used normally to detect throttle angle through the whole range, and a special second one which measures just the first part of the opening for higher resolution for use with idle control.

So why did they design this overcomplicated solution when much simpler solutions had already been in place for years? My guess is that they wanted to get their "feet wet" with Drive-By-Wire without the total commitment of it, so that they would be better prepared for the next generation that would use drive-by-wire.

**somebody5788** · 08-13-2009 07:08 AM

I have a complete wiring harness from a 2001 Auto 1.8t. If anyone wants it to run stand alone w/ PM me w/ an offer. It's in good condition except for a couple of clips here and there that aren't what they should be but will work I believe.

**pac1085** · 08-13-2009 08:25 AM

Wouldn't be that useful since it doesn't have the drive by cable throttle body connector on it.

**somebody5788** · 08-13-2009 08:41 AM

I figured it would work for someone w/ an ATW engine though. I mean you may have to convert to drive by cable to use the megasquirt IDK but it should still work w/ the TPS right?

**pac1085** · 08-17-2009 01:30 PM

I played around with PWM idle with the stock throttle body the other day a bit, and wasn't able to make it useful with the PWM frequencies that the MS2/Extra offers (multiples up to 8 of 30.5hz) - I think it runs at a much higher frequency. I bought this board: http://www.jbperf.com/pwm_converter/index.html which will hopefully allow me to use the idle motor in the stock throttle body. If not, I purchased a 2-wire bosch PWM IAC valve which works at 80hz, I just don't really want to weld a bung into my manifold.

**Enclave** · 08-17-2009 11:26 PM

Originally Posted by pac1085

I played around with PWM idle with the stock throttle body the other day a bit, and wasn't able to make it useful with the PWM frequencies that the MS2/Extra offers (multiples up to 8 of 30.5hz) - I think it runs at a much higher frequency. I bought this board: http://www.jbperf.com/pwm_converter/index.html which will hopefully allow me to use the idle motor in the stock throttle body. If not, I purchased a 2-wire bosch PWM IAC valve which works at 80hz, I just don't really want to weld a bung into my manifold.

I've tried up to 60hz with my standalone, its better but the control is more on and off. I actually am using a 3-wire bosch iac valve and just ran a hose from the valve to one of the ports on the intake manifold. Works great and have full closed loop idle control. Even set it up to bump up the idle when I turn on my A/C.

The only issue I ran into and you might also is that the built in iac motor leaves the throttle plate open a little bit causing a higher base idle. I solved this by reversing 12v and gnd to the built in iac motor that closed the throttle plate completely giving me full control of where the idle is with the 3-wire bosch iac valve. The cable mechanical portion of the TB is completely separate from the built in iac motor so there are no safety concerns with that.

**Kyle H** · 11-23-2009 09:22 AM

So is anybody DD'ing a megasquirted car yet?

**pac1085** · 12-13-2009 05:31 PM

Mine was my DD from mid 2007 till dec 2008, then I bought the V6.

**JK35** · 08-05-2010 02:20 PM

As many of you know, I have the AEM Race EMS on my B5, and have gotten incredible results by it. I'm working on development of a drop in and plug in mil-spec wiring harness to allow anyone who can afford AEM EMS, to have it!
The tuning is to a point that you can essentially stick the key in the ignition, crank it up and drive away, and with Autotuning activated, and EGT feedback 02 feedback, knock control and a number of other features used, a 3-5mile drive is all it takes to achieve VERY close results.
and remember, EVERYONE knows AEM... Find a tuner at a dyno shop that doesn't, and I'd say something's wrong with that picture.

The ignition system I chose to use on MINE is a TwinFire CDI and Denso Pencil Coils. -works great, I love it, BUT! there is something better I found for the systems I am trying to develop for market...
and this is why I am posting here...

Have any of you tried to use the D585 CPP / CNP setup?
There's a lot of people using these coils with superb results. from AUDI to Nissan to you name it! I'm finding these in use by professional motorsport teams even, and since my AEM drop in system needed a cost effective, stable and POWERFUL ignition system, I thought I'd give this a try.
-Glad I did...
If anyone is interested insetting up an ignition system like this, be it for Megasquirt, 034 or pretty much any standalone platform... I'd be happy to share what I know. just drop me a message!

**pac1085** · 09-10-2012 05:44 AM

I need to update this thread quite a bit, but here's a link to my page on MSRuns: http://msruns.com/viewtopic.php?f=87&t=22556

My MSQ file is attached to that post, but you need to login to downlaod it.

I'm now running Megasquirt 3 with the MS3X board - a huge upgrade over the version I was running when I posted this.

Wired into the stock engine harness, using TSI coils, cam and crank sensor. Also have boost control working via a MAC solenoid - likely could have got it working with an N75, but mine was bad.

**lorge1989** · 03-21-2013 08:13 PM

Pac, great thread. I have an aeb motor I'm going to put ms3 on in a few months if everything goes as planned. I still need to see where to buy from though. Im assuming you reccomend diy autotune?

**pac1085** · 04-07-2013 05:37 AM

Yea, I bought all my stuff from Diyautotune.

**Vierings** · 04-21-2013 05:03 PM

I will soon be embarking on megasquirt for my 97 1.8t. I have a friend that will wire the stock ecu connector to the MS unit so that I can plug it in and go and also have several friends that are familiar with tuning MS. Looking forward to finding out what I will be able to accomplish using the system. Been starting to read lots and have a ton more to read. In due time I will be running my car daily on MS. The car is currently running a frankenturbo on a unitronic 440 tune. The reason that I am going to MS is I want to get into a more solid tune for my set up, and in time I plan to increase the power and would rather just be able to re tune on MS than have to pay to upgrade or get a new tune. Future plans for the car (once I have MS running) will include likely a GT35r and building into a track car. Eventually the engine and tune may find its way into a Coupe Quattro for a daily and I will do it all over again swapping a tdi into the b5. (Why? Because I want to, a tdi quattro would be awesome!) Likely after I get the tdi up in the A4, I will possibly go even bigger with the CQ.

**Mythbuster74** · 02-20-2014 05:44 AM

Originally Posted by Ziggydub

I will soon be embarking on megasquirt for my 97 1.8t. I have a friend that will wire the stock ecu connector to the MS unit so that I can plug it in and go and also have several friends that are familiar with tuning MS. Looking forward to finding out what I will be able to accomplish using the system. Been starting to read lots and have a ton more to read. In due time I will be running my car daily on MS. The car is currently running a frankenturbo on a unitronic 440 tune. The reason that I am going to MS is I want to get into a more solid tune for my set up, and in time I plan to increase the power and would rather just be able to re tune on MS than have to pay to upgrade or get a new tune. Future plans for the car (once I have MS running) will include likely a GT35r and building into a track car. Eventually the engine and tune may find its way into a Coupe Quattro for a daily and I will do it all over again swapping a tdi into the b5. (Why? Because I want to, a tdi quattro would be awesome!) Likely after I get the tdi up in the A4, I will possibly go even bigger with the CQ.

So did you ever get it to work? And why has this not taken off in the Audi world?

We wouldn't be stuck paying all the money on a eurodyne suite or out of the box tunes that don't work well.

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**Drunken_M** · 08-15-2014 02:16 AM

I have an 96 A4 B5 1.8TQ with AEB running MS3X, just stock ICM and coils in sequential ignition and fueling, and used all the stock sensors. Working great, only "problem" is the idle control is a bit hard, so it idles a bit low. But havent really tried to get it any better yet. Used this system on Frankenturbo F21 turbo, 50 trim turbo, and now Holset HX35, no problem to use for an DD car. I will always recommend the MS3X version for all 1.8T owners, because are engines are sequential from factory this is the easiest and best solution.

**lorge1989** · 09-24-2014 10:39 AM

Originally Posted by Drunken_M

I have an 96 A4 B5 1.8TQ with AEB running MS3X, just stock ICM and coils in sequential ignition and fueling, and used all the stock sensors. Working great, only "problem" is the idle control is a bit hard, so it idles a bit low. But havent really tried to get it any better yet. Used this system on Frankenturbo F21 turbo, 50 trim turbo, and now Holset HX35, no problem to use for an DD car. I will always recommend the MS3X version for all 1.8T owners, because are engines are sequential from factory this is the easiest and best solution.

Have you considered adding an external idle control valve simply plumbed to the manifold? Thats my plan eventually, just have more work to be done before then.

**Drunken_M** · 10-07-2014 08:06 AM

Yes i have considered it, but the screw to open the throttle body a tad works great, so i didnt bother. Im going to try MS3X on both my S4 2.7TT engine and 2.8 30V engine soon.

**Tanweer_Hassan** · 02-17-2024 10:23 PM

Originally Posted by Enclave

I've tried up to 60hz with my standalone, its better but the control is more on and off. I actually am using a 3-wire bosch iac valve and just ran a hose from the valve to one of the ports on the intake manifold. Works great and have full closed loop idle control. Even set it up to bump up the idle when I turn on my A/C.

The only issue I ran into and you might also is that the built in iac motor leaves the throttle plate open a little bit causing a higher base idle. I solved this by reversing 12v and gnd to the built in iac motor that closed the throttle plate completely giving me full control of where the idle is with the 3-wire bosch iac valve. The cable mechanical portion of the TB is completely separate from the built in iac motor so there are no safety concerns with that.

Hi, I assume you no longer have your car, but do you perhaps have photos of the IAC connection. And did it work well in real world applications.

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