Bosch electronic fuel injection.

[John Boyes]

Has anyone experience of fitting Bosch Motronic Fuel Injection to TR6/5?  I’ve fitted up the manifolds, fuel lines, various sensors, harness but I’m struggling as to how to power it up and interlock to the fuel pump.  Does anyone have any any experience of this or wiring diagrams.  I believe, but not sure, that the system was originally fitted to an Opel Commadore circa 1970’s.  Many thanks.  John.

[FatJon]

Bosch motronic didn’t exist in the 70s. Maybe Dtronic, Jetronic or or some very early system. You are biting off a lot to chew there. They are not mappable and dedicated to the engine they are built for. Not impossible to make it work but difficult, specialised and expensive and with limited access to parts and information. There are much easier and cheaper ways to retrofit fuel injection.

[mtrehy]

6 hours ago, John Boyes said:

Has anyone experience of fitting Bosch Motronic Fuel Injection to TR6/5?  I’ve fitted up the manifolds, fuel lines, various sensors, harness but I’m struggling as to how to power it up and interlock to the fuel pump.  Does anyone have any any experience of this or wiring diagrams.  I believe, but not sure, that the system was originally fitted to an Opel Commadore circa 1970’s.  Many thanks.  John.

Bizarre idea. Mega or microsquirt if you're on a budget. 

[stuart]

The usual EFI set up back 20 yrs ago to fit to a 6 was from a Vauxhall Senator which was pretty much a straight fit though you needed to figure out the ECU connections, ran with a single AF body.

Stuart.

[FatJon]

2 hours ago, mtrehy said:

Bizarre idea. Mega or microsquirt if you're on a budget. 

Megasquirt 3 on mine, runs lovely. Big fat sparks from a 6 tower coil, Idle speed control, wideband lambda, silky smooth running, much improved consumption and a lot less stinky than the Lucas due to the better mixture control.

Not hugely expensive depending on how you go about it. I went with a baustuck manifold and Jenvey throttle bodies which did add up but with a bit of engineering skill you can use the OE bodies.

I suppose a 70s or 80s period system has it’s attractions on a car of that era but quite a project to get it done.

 

[Brent C]

TR electroic injection.doc

Hi John

Is this the diagram you are looking for, it is for Bosch L-Jetronic.

Brent

[TRier]

20 hours ago, FatJon said:

Megasquirt 3 on mine, runs lovely. Big fat sparks from a 6 tower coil, Idle speed control, wideband lambda, silky smooth running, much improved consumption and a lot less stinky than the Lucas due to the better mixture control.

Not hugely expensive depending on how you go about it. I went with a baustuck manifold and Jenvey throttle bodies which did add up but with a bit of engineering skill you can use the OE bodies.

I suppose a 70s or 80s period system has it’s attractions on a car of that era but quite a project to get it done.

 

Don't want to hijack John Boyes thread here but are using that coil in a wasted spark config? AFR feedback in real time to the Megasquirt from the oxygen sensor? Quite interested in your experiences with that if you have time to elaborate a bit. 

[John Boyes]

On 4/5/2022 at 4:13 PM, FatJon said:

Bosch motronic didn’t exist in the 70s. Maybe Dtronic, Jetronic or or some very early system. You are biting off a lot to chew there. They are not mappable and dedicated to the engine they are built for. Not impossible to make it work but difficult, specialised and expensive and with limited access to parts and information. There are much easier and cheaper ways to retrofit fuel injection.

 

On 4/5/2022 at 4:13 PM, FatJon said:

Bosch motronic didn’t exist in the 70s. Maybe Dtronic, Jetronic or or some very early system. You are biting off a lot to chew there. They are not mappable and dedicated to the engine they are built for. Not impossible to make it work but difficult, specialised and expensive and with limited access to parts and information. There are much easier and cheaper ways to retrofit fuel injection.

Agree, I think Motronic was the “brand” not the actual “model”.  The model is probably L-Jetronic.  This system has been used on TR6’s very successfully some years ago and has been published in magazines.  It has worked, but agree if starting today I would probably do something with a programmable ECU.  The system is Lamda driven at standard conditions, with fixed ECU changes to injection rate as conditions vary.  I may well end up using a modern programmable ECU.

 

23 hours ago, mtrehy said:

Bizarre idea. Mega or microsquirt if you're on a budget. 

Not so bizarre, it has worked well on TRs in the past.

[John Boyes]

23 hours ago, stuart said:

The usual EFI set up back 20 yrs ago to fit to a 6 was from a Vauxhall Senator which was pretty much a straight fit though you needed to figure out the ECU connections, ran with a single AF body.

Stuart.

Stuart, I think the Senator was the UK version of the Commadore.  Yes the connections are my current challenge!!  But everything else bolts up perfectly.

[John Boyes]

2 hours ago, Brent C said:

TR electroic injection.doc 241 kB · 13 downloads

Hi John

Is this the diagram you are looking for, it is for Bosch L-Jetronic.

Brent

Thanks Brent, that’s great.  However I don’t have access to a decent computer until next week to download, I’ll reply more fully once I’ve had a good look at it.  Thanks again.

[FatJon]

18 minutes ago, TRier said:

Don't want to hijack John Boyes thread here but are using that coil in a wasted spark config? AFR feedback in real time to the Megasquirt from the oxygen sensor? Quite interested in your experiences with that if you have time to elaborate a bit. 

Yes, exactly as you describe it. Opel Omega V6 wasted spark coil, Zeitronix wideband AFR system. Can post up config if it’s OK with John, don’t want to be a hijacker either but it may also be useful for him if he goes that way.

[TRier]

22 minutes ago, FatJon said:

Yes, exactly as you describe it. Opel Omega V6 wasted spark coil, Zeitronix wideband AFR system. Can post up config if it’s OK with John, don’t want to be a hijacker either but it may also be useful for him if he goes that way.

I guess its very useful info in the wider EFI context anyway and John is knee deep in EFI right now!

[mtrehy]

3 hours ago, John Boyes said:

 

Agree, I think Motronic was the “brand” not the actual “model”.  The model is probably L-Jetronic.  This system has been used on TR6’s very successfully some years ago and has been published in magazines.  It has worked, but agree if starting today I would probably do something with a programmable ECU.  The system is Lamda driven at standard conditions, with fixed ECU changes to injection rate as conditions vary.  I may well end up using a modern programmable ECU.

 

Not so bizarre, it has worked well on TRs in the past.

and? hardly the logical choice in 2022

[John Boyes]

14 hours ago, mtrehy said:

and? hardly the logical choice in 2022

 

14 hours ago, mtrehy said:

and? hardly the logical choice in 2022

And what? I started the project 15 years ago but got diverted by proper motor racing in historic single seaters.  Only just restarted the project.

[John Boyes]

17 hours ago, FatJon said:

Yes, exactly as you describe it. Opel Omega V6 wasted spark coil, Zeitronix wideband AFR system. Can post up config if it’s OK with John, don’t want to be a hijacker either but it may also be useful for him if he goes that way.

 

Just now, John Boyes said:

 

And what? I started the project 15 years ago but got diverted by proper motor racing in historic single seaters.  Only just restarted the project.

 

1 minute ago, John Boyes said:

 

And what? I started the project 15 years ago but got diverted by proper motor racing in historic single seaters.  Only just restarted the project.

 

17 hours ago, TRier said:

I guess its very useful info in the wider EFI context anyway and John is knee deep in EFI right now!

Any hijacking OK by me, but I’m new to the Forum and don’t know the protocols.  But thanks for asking!!

[FatJon]

This is the general drawing for a Megasquirt V3 so it shows all kinds of options. I used the stepper motor idle controller from Jenvey so PWM idle controller wiring is not used. Instead you use the outputs IAC1A, 1B, 2A, 2B to drive the 4 wire stepper.

I used a Wideband EGO (Lambda) so the wiring for the narrow band is not needed. The one I used http://www.zeitronix.com/Products/Zt-3/Zt-3.shtml

In the past I have used cheaper Innovate widebands but found them VERY unreliable, your money, your choice. Racestorations can supply a timing  cover with the bracket for a crank position sensor (a weber marelli unit as used on Sierra Cosworth). They also have a TR6 crank pulley with the toothed trigger wheel on it. Neither of these are cheap but they solve a problem that can otherwise take some hours or days to solve by making up your own crank trigger assembly. I took the easy option and it works very well. Accuracy matters here. That toothed pulley must have fractions of a MM runout and the sensor needs to be 1mm from the teeth. This is THE most common problem people have. The ECU needs to reliably see every tooth and the gap and if it’s all wobbling, vibrating, sensor flopping around loose, or the sensor is 5mm away it will not work.

You will need to add a second coolant temperature sensor for the ECU only. There is a spare port on the TR6 stat housing with a blanking plug in, perfect for this, 5/8BSP if I recall correctly but don’t take my word for it from a year ago. If the sensor will screw in it will work as you configure it in the software by measuring the resistance in iced water, room temperature and boiling water then put in the 3 values and the software does the rest. Same procedure with the air temperature sensor. The air temp sensor needs to see the air at the temperature at which it goes into the engine not simply the ambient temperature otherwise the fuel calculations go to hell as the under bonnet temperatures vary from the ambient, like in a traffic jam.

Throttle position sensor will require a bit of engineering skill. You can use pretty much any kind from any engine that you can fandangle to make it fit, and it just sits on the end of the throttle spindle to see the throttle angle. I used Jenvey throttle bodies and they did one to fit. They are much of a muchness though and you can configure any to work within the software. You click a button when the throttles are closed, click a button when they are wide open and that’s it configured as the ECU works out the angles in between.

The injectors I used were Bosch standard EV6 style BMW 200cc units, £150 for 6 off eBay. I dare say they are Chinese and never been anywhere near Bosch but they work perfectly well.

The fuel pressure regulator is a generic off the shelf one for about £30, 3 bar, manifold pressure referenced. The fuel rail is your choice. Go expensive with Jenvey bodies or similar and you get one ready made, save some money by remodelling the existing throttle bodies and the rail will have to be made to fit. Pipework is simple, one end goes to the fuel pump, the other goes to the pressure regulator and back to the tank. The pump is any modern injection pump and the system is a recirculating system so no more grief with red hot fuel cavitating and causing breakdowns. The old TR pump and regulator go on Ebay. You will need a return on the tank and good filtering. Get the tank cleaned while it's off, you do not want 50 years of rust and gunk going round the pipes. The pump MUST be mounted lower than the tank, EFI pumps do not like having to lift fuel.

My setup uses manifold pressure to control fuelling at low RPMs and small throttle angles then blends over to using only throttle angle at wider throttles. This gives a good balance of smoothness at low speeds and accurate mixture when “giving it some”. To get a good smooth manifold pressure reading I took small pipes from each manifold runner to a block I made up and then one pipe to the ECU pressure sensor (built in). All this configuration for blended fuelling is built into my map which is attached as a good starting point for tweeking. This blended system also allows you to use the idle speed control functions in the ECU. If you use throttle angle only the ECU does not know that the air valve is adding or cutting air to adjust the idle and the mixture goes to pot. The off the shelf systems do not have the function which is why I didn't go with an off the shelf, plus I love fiddling.

 

The ECU can be ordered with the coil pack drivers built in or you can use external ones. I went having the coil drivers built in, of course you can even go for coil on plug if you wish but that struck me as an expensive overkill for a TR6, unless your strapping a big turbo on it! You will note that on the drawing you see only one coil output, that’s because it’s a generic drawing, on an ECU configured form a TR6 with wasted spark there will be 3 outputs. One for each coil pair.

ECU came from this chap whom is very helpful and knowledgeable.  http://extraefi.co.uk/products/MS_All_products.html, the option I went for was the 6 cylinder wasted spark with batch fuelling. You can’t go sequential without a cam sensor and that’s a whole level of pain to add to a TR6 engine and really no benefit. Be sure you specify that you want coil drivers built in and the wires in the loom for the stepper idle control valve as these are not standard options. On the subject of looms, you get the ECU loom with the ECU so that bit is dead easy. My ECU is mounted high up in the passenger footwell and the loom to the engine comes through a gland into the engine bay. In the engine bay I have a separate fuse box for the fuses related to the EFI and a few relays for fan control, fuel pump and Ignition.

 

I have also attached my working configuration file. It still needs a few tweeks here and there but it’s 95% there.

This is a solution for the brave, you need to understand wiring, a little basic electronics/electrics and be capable of working with a computer. If you are not able to handle this just buy an off the shelf kit and save yourself a lot of grief.

 

Edited April 7, 2022 by FatJon

[john.r.davies]

This has been a popular subject over on Sideways Technologies.

See: https://sideways-technologies.co.uk/forums/index.php?/search/&q=EFI&quick=1

[FatJon]

Forgot to add config file.

TR6 ITB.zip

[FatJon]

1 minute ago, john.r.davies said:

This has been a popular subject over on Sideways Technologies.

See: https://sideways-technologies.co.uk/forums/index.php?/search/&q=EFI&quick=1

I can see why, it's a fascinating subject. Quite a steep learning curve but now I done a few over the years it's pretty straightforward. It is nice when you get to the end and it's all your own work, not a preprogrammed off the shelf kit. Just doing my TVR with the AJP V8, now that one really is a learning curve, very unusual engine.

[TRier]

8 hours ago, FatJon said:

This is the general drawing for a Megasquirt V3 so it shows all kinds of options. I used the stepper motor idle controller from Jenvey so PWM idle controller wiring is not used. Instead you use the outputs IAC1A, 1B, 2A, 2B to drive the 4 wire stepper.

I used a Wideband EGO (Lambda) so the wiring for the narrow band is not needed. The one I used http://www.zeitronix.com/Products/Zt-3/Zt-3.shtml

In the past I have used cheaper Innovate widebands but found them VERY unreliable, your money, your choice. Racestorations can supply a timing  cover with the bracket for a crank position sensor (a weber marelli unit as used on Sierra Cosworth). They also have a TR6 crank pulley with the toothed trigger wheel on it. Neither of these are cheap but they solve a problem that can otherwise take some hours or days to solve by making up your own crank trigger assembly. I took the easy option and it works very well. Accuracy matters here. That toothed pulley must have fractions of a MM runout and the sensor needs to be 1mm from the teeth. This is THE most common problem people have. The ECU needs to reliably see every tooth and the gap and if it’s all wobbling, vibrating, sensor flopping around loose, or the sensor is 5mm away it will not work.

You will need to add a second coolant temperature sensor for the ECU only. There is a spare port on the TR6 stat housing with a blanking plug in, perfect for this, 5/8BSP if I recall correctly but don’t take my word for it from a year ago. If the sensor will screw in it will work as you configure it in the software by measuring the resistance in iced water, room temperature and boiling water then put in the 3 values and the software does the rest. Same procedure with the air temperature sensor. The air temp sensor needs to see the air at the temperature at which it goes into the engine not simply the ambient temperature otherwise the fuel calculations go to hell as the under bonnet temperatures vary from the ambient, like in a traffic jam.

Throttle position sensor will require a bit of engineering skill. You can use pretty much any kind from any engine that you can fandangle to make it fit, and it just sits on the end of the throttle spindle to see the throttle angle. I used Jenvey throttle bodies and they did one to fit. They are much of a muchness though and you can configure any to work within the software. You click a button when the throttles are closed, click a button when they are wide open and that’s it configured as the ECU works out the angles in between.

The injectors I used were Bosch standard EV6 style BMW 200cc units, £150 for 6 off eBay. I dare say they are Chinese and never been anywhere near Bosch but they work perfectly well.

The fuel pressure regulator is a generic off the shelf one for about £30, 3 bar, manifold pressure referenced. The fuel rail is your choice. Go expensive with Jenvey bodies or similar and you get one ready made, save some money by remodelling the existing throttle bodies and the rail will have to be made to fit. Pipework is simple, one end goes to the fuel pump, the other goes to the pressure regulator and back to the tank. The pump is any modern injection pump and the system is a recirculating system so no more grief with red hot fuel cavitating and causing breakdowns. The old TR pump and regulator go on Ebay. You will need a return on the tank and good filtering. Get the tank cleaned while it's off, you do not want 50 years of rust and gunk going round the pipes. The pump MUST be mounted lower than the tank, EFI pumps do not like having to lift fuel.

My setup uses manifold pressure to control fuelling at low RPMs and small throttle angles then blends over to using only throttle angle at wider throttles. This gives a good balance of smoothness at low speeds and accurate mixture when “giving it some”. To get a good smooth manifold pressure reading I took small pipes from each manifold runner to a block I made up and then one pipe to the ECU pressure sensor (built in). All this configuration for blended fuelling is built into my map which is attached as a good starting point for tweeking. This blended system also allows you to use the idle speed control functions in the ECU. If you use throttle angle only the ECU does not know that the air valve is adding or cutting air to adjust the idle and the mixture goes to pot. The off the shelf systems do not have the function which is why I didn't go with an off the shelf, plus I love fiddling.

 

The ECU can be ordered with the coil pack drivers built in or you can use external ones. I went having the coil drivers built in, of course you can even go for coil on plug if you wish but that struck me as an expensive overkill for a TR6, unless your strapping a big turbo on it! You will note that on the drawing you see only one coil output, that’s because it’s a generic drawing, on an ECU configured form a TR6 with wasted spark there will be 3 outputs. One for each coil pair.

ECU came from this chap whom is very helpful and knowledgeable.  http://extraefi.co.uk/products/MS_All_products.html, the option I went for was the 6 cylinder wasted spark with batch fuelling. You can’t go sequential without a cam sensor and that’s a whole level of pain to add to a TR6 engine and really no benefit. Be sure you specify that you want coil drivers built in and the wires in the loom for the stepper idle control valve as these are not standard options. On the subject of looms, you get the ECU loom with the ECU so that bit is dead easy. My ECU is mounted high up in the passenger footwell and the loom to the engine comes through a gland into the engine bay. In the engine bay I have a separate fuse box for the fuses related to the EFI and a few relays for fan control, fuel pump and Ignition.

 

I have also attached my working configuration file. It still needs a few tweeks here and there but it’s 95% there.

This is a solution for the brave, you need to understand wiring, a little basic electronics/electrics and be capable of working with a computer. If you are not able to handle this just buy an off the shelf kit and save yourself a lot of grief.

 

Very interesting, thanks. Sequential is likely only of much advantage at idle and lower throttle positions and you have covered that off with a kind of fuzzy logic solution around manifold pressure and the transition to TPS as feedback anyway. 
So, what’s the outcome? Any figures or feelings on power and consumption?

[FatJon]

Outcome is a pleasure to drive. Starts cleanly with a 1250 rpm idle, gradually drops to 850 when warm. Power feels improved though it’s not been on a rolling road. Pick up, acceleration and general smoothness are transformed and it’s certainly noticeably quicker than it was with the original injection and distributor. It also smells better, less eye stinging over rich mixture which is nice when the lid is down. Consumption, hard to quantify exactly as I have not done many miles yet, ran out of summer but certainly better. 

You can also gently lift the clutch to crawl in traffic with no throttle like a modern car as the idle valve prevents stall and just keeps it crawling gently. Combined with the  servo upgrade it just feels nicer to drive. An old classy car but with more modern manners.

[CK's TR6]

My cam sensor was pretty butt simple. Took a existing distributor (tach drive!) broke the bell off. Turned the remaining stub on a lathe to a cylinder. 3D printed a plastic block to fit over that and that a 3 wire sensor would fit into. Took the original internals and ground off the pivot pins for the weights and trimmed down that plate to be a single tooth. The MS3X manuals talk about when the tooth should be there timing wise. Not supercritical. The software polls the sensor when it thinks it should and the tooth is either there or not.

[TRier]

4 hours ago, CK's TR6 said:

My cam sensor was pretty butt simple. Took a existing distributor (tach drive!) broke the bell off. Turned the remaining stub on a lathe to a cylinder. 3D printed a plastic block to fit over that and that a 3 wire sensor would fit into. Took the original internals and ground off the pivot pins for the weights and trimmed down that plate to be a single tooth. The MS3X manuals talk about when the tooth should be there timing wise. Not supercritical. The software polls the sensor when it thinks it should and the tooth is either there or not.

Yeah that was a good idea, I had similar thought, certainly no harm to have the cam sensor but not sure how much benefit sequential over batch is though. So what has your experience been with the EFI over mechanical in terms of power and efficiency?

 

Niall

[AWM]

As regards ignition with Megasquirt, I had a good outcome using the Ford EDIS Wasted Spark system on a Rover V8 I did a few years ago, and I've now sourced a six cylinder version for my forthcoming MS V3 installation on my US Spec. (ie. Carbs) Car that I want to upgrade to fuel ignition. Can be a bit hard to source here but they are out there.

[FatJon]

28 minutes ago, AWM said:

As regards ignition with Megasquirt, I had a good outcome using the Ford EDIS Wasted Spark system on a Rover V8 I did a few years ago, and I've now sourced a six cylinder version for my forthcoming MS V3 installation on my US Spec. (ie. Carbs) Car that I want to upgrade to fuel ignition. Can be a bit hard to source here but they are out there.

EDIS is rather old and has some drawbacks on a modern MS3 setup, if you have the toothed wheel and sensor for the EDIS you have pretty much all you need to not use the EDIS. With EDIS you can’t use several diagnostic features like tooth capture and the logging of timing can be hit and miss. My advice is to avoid it.