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Electronic engine management / Megasquirt

A controversial topic among TR6 friends…I just wanted to finally tackle it:
I've been struggling with electronic injection since my Kawasaki Z1100 GP (built in '81) and already wanted to install a Megasquirt injection system in my Suzuki TL1000R (which failed in the early 2000s due to a lack of available hardware and software), so now I've done it on my TR6:


A big praise and thanks go to Andreas, who is one of the pioneers with the Megasquirt on the TR6 and saved me a lot of work and learning money and without whom the conversion would not exist…
Thanks also to Sascha, who was available as a sparring partner. And last but not least to Harry, who put up with the crying…;-)

An electronic engine management system (hereinafter referred to as “EFI”) basically doesn't give you any more horsepower than you have with a perfectly adjusted PI system or carburetors (e.g. triple Weber)… What you get is:
A proper ignition spark in every (!!1elf) situation and always the right mixture….and that usually brings more power than can be achieved with “analog” technology, because hardly anyone gets it perfectly adjusted….
If I set the ignition timing on the EFI to 11.4° from TDC, then it sparks at 11.4° before TDC…. and doesn't wander between 11° and 13° at idle, doesn't change depending on whether I'm revving up or down (keyword: timing chain) or the distributor shaft bobbles because the guide is worn out…
I also always have optimum charging time of the coil….egal, whether at 800 rpm or 6000 rpm…is simply not feasible with a contact ignition!

You can read below which control and hardware components are available and why I chose them…..


Control unit / ECU

I bought a “MegaSquirt-III with PCB V3.0 Kit” from and built it up… To be able to test the whole thing before installation, there was also a JimStim v1.5 from the same source …. Highly recommended!

There's not really much to write about this: Print out the assembly instructions and work through them step by step… All you need is an 80-watt soldering station, some good solder and a small side cutter…

In the meantime, I have to admit: An MS2 would have done as well and would have been easier to set up…With the MS3, however, you have the option of implementing sequential injection and other gimmicks. For example, I have two modes: “fuel saving” and “fun”, which I can select via a switch

Alternative engine management computers are for example (in random order):

If you want to try it yourself, I recommend the Megasquirt and one of the top three….


I used a 6.5 inch 36-1 tooth wheel from as the trigger wheel for detecting the crankshaft position…I also ordered the crankshaft sensor and a fuel injector connector kit here…. A friend combined the whole thing with a new pulley and balanced it for me…now has the same weight as the original pulley…just with “teeth” Essential component, without which (almost) nothing works….You just have to find out somehow where the pistons are in order to be able to inject and ignite correctly… If necessary, this can also be done with a signal from the ignition distributor…but then without ignition control….


Here I use an original BOSCH fuel pump 0 580 254 950 from a Mercedes Benz series W124
15mm inlet and lowest power consumption at the required pressure
Nevertheless, I will still convert it to PWM control…is no problem together with a pressure sensor and the Megasquirt… Update: The PWM control works (alone) and has to be, after a measurement at idle on the return from the pressure regulator → tank showed 120L/h… This is definitely too much and only leads to heating of the fuel, which you don't want! I will reduce it to max. 80L/h or have it completely regulated by the MS…there has to be a minimum quantity at the return flow so that the fuel rail always has cool fuel…


Pipes: 4 meters cost 20,- you need 2 pieces… Plus the matching Dash6 fittings…either also from Sandtler, or from Arlows

The two lines / hoses run parallel to the brake line under the car and are heat-insulated accordingly


You should include a fuel cooler in the return line, which is mounted before the water cooler…

I didn't install one and didn't have any problems even in summer 2018… Possibly interesting when driving over mountain passes.


come with mri from the Opel Omega V6…are available used from 25€ in the bay….25€ per set! if you use an injection nozzle calculator (e.g. ) you will find out that you need nozzles around 150cc/min at target fuel pressure…the Opel ones deliver 208cc and are therefore almost “too big”, because you can't get a proper mixture at idle if the opening times are too short…

Throttle boddies

There are various options here… The most “original” way, which I also took, is to extend a throttle valve system from the TR5/6 PI with a throttle valve sensor and to enlarge the bore for the injection nozzles. The seal and seat for the old injectors remains untouched and the whole thing can be removed without leaving any residue….

Suitable solutions are required for carburetor engine conversions. These range from spacers that go between the carburetor and intake manifold and hold the injection nozzle ( ) to complete throttle valve systems costing thousands of euros

Many offerings are based on intake manifolds for Weber DCOE carburetors and correspondingly designed throttle bodies with injection nozzle mounts. This goes as far as DCOE “replicas” that are difficult to distinguish from carburetors:

Another way is the single throttle valve, which is also used in many everyday cars due to its simple design:

But it is not without reason that people like Ferrari/Lamborghini etc. used to install Weber twin carburetors (one throttle/cylinder) or today single throttle systems like in the BMW M5…. Throttle response etc. is completely different to that of a single throttle valve….

But it's all a question of money…

Fuel pressure

At 3.5 bar, it is well below the operating pressure of the old Lucas injection system of 7.5 bar. If you buy a complete Opel intake manifold, the matching fuel pressure regulator is usually included, which should be connected in parallel to the air pressure sensor. Background: When the throttle valves are closed/high vacuum, the fuel pressure is lowered. This allows longer injection times to be achieved at idle…better for the mixture formation…


The original distributor is used here…only the ignition coil is now fired by the ECU and no longer by the contact in the distributor… So you have the precise timing of a static ignition with the look of the original… Alternatively, you can also use the 6-pin ignition coil from the VW Golf VR6, for example… Even better (because more “fump!”) is a CDI (Capacitor Discharging Ignition) such as MSD 6, where the coil is charged with 430 volts and you get 95mJoul ignition spark…

Especially with the TR5/TR6PI, the freely programmable ignition is the biggest step forward, as the original PI only works with a speed curve and the accelerator pedal position (vacuum) is not included in the ignition timing. This has to do with the modest vacuum situation due to the 280° camshaft, which only generates a low vacuum anyway, which then quickly collapses when you accelerate. That's why Triumph/Lucas have dispensed with vacuum adjustment.

If you feel like it, you can even install a knock sensor and go to the limits of pre-ignition without destroying the engine.



The crankshaft sensor is a standard part, which was attached to the screws of the timing chain case with a self-made holder and detects the trigger wheel.

Coolant temperature

As Coolant Temperature Sensor (CLT) I ordered a GM sensor with the Megasquirt, because in Germany you usually only get some with M12x1,5 thread…but we need 3/8“ NPT… This only has to be turned off a little and finds its place in the water pump housing in the outlet of the “carburetor heater”, which is normally closed with a plug on the PI…so you always have the exact water temperature from the “small” circuit and don't get any interference from the original display in the system…

Air temperature

The Intake Air Temp Sensor (IAT) is an “Open Element” sensor from GM, which reacts much faster than the CLT mentioned above. For this you need a to be able to weld it to the holder of the air filter….


The MPX4250 supplied in the kit is used here, which is attached to the vacuum connection of the center throttle body with a 4mm pressure line from No-Limits-Motorsport and a self-soldered adapter.

Throttle position sensor

The throttle position sensor (TPS) is a standard Ford part which sits on the extended shaft of the front throttle body with a bracket…

Lambda sensor

Here I continue to use the Innovate MTX-L with Bosch LSU 4.9, which I have already used to tune the Lucas injection…for the Megasquirt a Spartan2 controller with LSU 4.9 sensor is also sufficient. To attach the probe, a suitable sleeve was welded into the manifold at the time…the angle is important so that condensation can run out of the probe…so please mount it in the upper semicircle of the pipe…otherwise condensation cannot run out and it only lasts 1 month…

Wiring harness

Here I would stick to the cable colors from the official documentation. I bought my cables + protective hoses by the meter from Peter Böllmann at wanted to have a look at his store anyway… Otherwise, the ready-made wiring harness from him at is also recommended. For the other EFIs, there are usually also ready-made wiring harnesses with loose ends, which you then only have to connect to the respective sensors…


Programming / parameterization

1. you need a laptop….I no longer want to do without the auto-tune function of the Tunerstudio software from EFI Analytics…
Either you have a long-lasting battery or get a suitable car adapter for the power supply…a backup of the settings is also created before each change, so that you can always go back to a working config

2. the Megasquirt is connected via a serial connection…..either by (USB) cable or by radio… I bought a HC-06 Bluetooth module for 5,-€ on Ebay…after I managed to change the connection speed of the module to 115200 BAUD, it works great…

3. together with the Bluetooth module, the Megasquirt can also be controlled via smartphone/tablet …. I don't want to program it…but while Google Maps is navigating in the background, you can look at a few colorful bars…

Bluetooth module

The HC-06 mentioned above is good and cheap…unfortunately the documentation to be found in the I_Net is not always up to date…with the latest firmware the AT command sets have unfortunately changed to set the module to the BAUD rate of 115200 required for our purposes (the thing runs at 9600 by default)

Connect the module to the PC via USB ↔ serial adapter or - if still available - COM port and use Teraterm to copy and paste the commands:

AT+NAME:wunschname setzt die Kennung auf “wunschname”
AT+PSWD:“0000” setzt den PIN auf 0000
send… All commands must be acknowledged with an “OK”…

Then interrupt the connection and re-establish it…but now with 115200 BAUD… an “AT” should return an “OK”…

en/start/2_tr6/megasquirt.txt · Last modified: 22:46 05 /11/2023 by peter