95 replies to this topic

[miniBrain]

I don't think you'd have to develop a wideband, unless you wanted to. All the available ones I know of have an analogue AFR output (0-5v), or  some sort of serial interface for data logging.

 

One Arduino project I'd do if I had the skill and time would be to emulate an OBD data stream through bluetooth, so I could take advantage of existing smart phone apps like Torque Pro.

 

From what I've read, I think you have to provide the sensor with a bias voltage proportional to its output, although I don't fully understand them yet. If there's a "plug'n'play" sensor out there though, I'll have one!

[Ethel]

I mean controllers, not the actual sensor.

[finch661]

this is amazing! have been tempted with doing an injection conversion for a while now. Is this system only injection, or does it also cover the ignition?

[miniBrain]

this is amazing! have been tempted with doing an injection conversion for a while now. Is this system only injection, or does it also cover the ignition?

 

 

Thanks mate, only injection but hope to add ignition later 

[finch661]

 

this is amazing! have been tempted with doing an injection conversion for a while now. Is this system only injection, or does it also cover the ignition?

 

 

Thanks mate, only injection but hope to add ignition later 

 

How have you found the car just using the standard ignition? 

[screech]

Thanks screech!
 
I'm using the Mini daily and I'm just loving the SPi set up - never going back to carbs if I can help it. I'm working on ECU version 2 - PCBs for it arrived today and I'm building one at the moment. This should give me multiport injection and programmed ignition - but its not going in the Mini though.
 
Be happy to answer any questions - if I can!

That sounds perfect! I've been contemplating injection for a long time now. I'm not expecting power, but cold starts and drivability is what I'm looking for.
What's you multipoint one going to be used on, a proper engine?

The first question I've got on the unit are what sensors are what...
I've figured out the TPS and idle stepper motor, I'm guessing the one on the right inlet tract is the air inlet temp?
And there's one right underneath in the middle, doesn't look like a removable one, just got 1 space terminal sticking out..?

Cheers

[miniBrain]

 

 

this is amazing! have been tempted with doing an injection conversion for a while now. Is this system only injection, or does it also cover the ignition?

 

 

Thanks mate, only injection but hope to add ignition later 

 

How have you found the car just using the standard ignition? 

 

 

Much the same as for carbs really. I'm not sure what to expect from programmed ignition but it *should* give a good improvement over the (probably worn) weights & springs in the dizzy.

[miniBrain]

 

Thanks screech!
 
I'm using the Mini daily and I'm just loving the SPi set up - never going back to carbs if I can help it. I'm working on ECU version 2 - PCBs for it arrived today and I'm building one at the moment. This should give me multiport injection and programmed ignition - but its not going in the Mini though.
 
Be happy to answer any questions - if I can!

That sounds perfect! I've been contemplating injection for a long time now. I'm not expecting power, but cold starts and drivability is what I'm looking for.
What's you multipoint one going to be used on, a proper engine?

The first question I've got on the unit are what sensors are what...
I've figured out the TPS and idle stepper motor, I'm guessing the one on the right inlet tract is the air inlet temp?
And there's one right underneath in the middle, doesn't look like a removable one, just got 1 space terminal sticking out..?

Cheers

 

 

Hi screech

 

The multipoint is going into a TR7 over the winter 

 

Hope this answers your questions:

 

The Air Temp sensor is in the air filter box. I can't say much more about this as I've never used it. I use an LM35 IC for air temp.

 

Underneath the manifold you've got the coolant temp sensor and the heater. I leave the heater on (connected to the ignition on circuit) and haven't attempted anything fancy. It only draws just over 1 amp so its not a great overhead. The coolant temperature sensor is shown on the left. I had to remove the coolant pipe to clear the tubular manifold, so I can't use this sensor at the moment. I use the coolant temp sensor on the head instead.

 

 

 

You've probably sussed this already but at the back there's two vacuum pipes -the one on the right goes through a vapour trap and then to the ECU MAP sensor. The red one goes to the air box and activates the hot air control flap (I believe its called a "Thermatic Valve"). I've blanked this off.

 

You can feed the dizzy vacuum advance by inserting a T piece in the MAP pipe, if required.

 

 

I've also blanked off the three connections at the front of the TBI. I haven't a clue what the two connections are at the base but I've connected them together.

 

 

Hope this helps!

[lawrence]

Very interesting read. You must have alot of expertise when it comes to the actual coding for the circuit board!
I'm sure the multi point injection and ignition controlled via arduino will work just as well as single point once you've got your head round the numbers!

Would you ever sell them on do you think? I know that programmable systems like megasquirt and nodiz go for pretty big money but then again if yours is a prototype and never in mass production you could collect some fairly good pocket money from people even after explaining the risks. Like you said earlier the spi ecu cost about £50 to get up and running. I know many tight members of the car community would pay even double that for a working prototype!

[finch661]

Very interesting read. You must have alot of expertise when it comes to the actual coding for the circuit board!
I'm sure the multi point injection and ignition controlled via arduino will work just as well as single point once you've got your head round the numbers!

Would you ever sell them on do you think? I know that programmable systems like megasquirt and nodiz go for pretty big money but then again if yours is a prototype and never in mass production you could collect some fairly good pocket money from people even after explaining the risks. Like you said earlier the spi ecu cost about £50 to get up and running. I know many tight members of the car community would pay even double that for a working prototype!

 

If you get the ignition side working, i would be interested (funds dependent though!)

[miniBrain]

Hi Lawrence, Well, I've been doing this sort of stuff for 30 years - one day I'll get the hang of it though!

 

I could build a couple of units at mate's rates for anyone willing to experiment. But I've still got a lot of work to do before I even get to that stage. If it all works well, then I'll publish the design or maybe sell it as a kit of parts - not thought that far ahead though.

 

In the meantime, here's the PCB version partially built - top side has the Arduino, power transistors, etc.

 

 

And the underside has various signal conditioning circuits:

 

 

The PCB's are superb - made in China for about £22 each in small quantities.

[miniBrain]

@finch661

 

 "If you get the ignition side working, i would be interested (funds dependent though!)" - Watch this space 

[screech]

 
Hi screech
 
The multipoint is going into a TR7 over the winter 
 
Hope this answers your questions:
 
The Air Temp sensor is in the air filter box. I can't say much more about this as I've never used it. I use an LM35 IC for air temp.
 
Underneath the manifold you've got the coolant temp sensor and the heater. I leave the heater on (connected to the ignition on circuit) and haven't attempted anything fancy. It only draws just over 1 amp so its not a great overhead. The coolant temperature sensor is shown on the left. I had to remove the coolant pipe to clear the tubular manifold, so I can't use this sensor at the moment. I use the coolant temp sensor on the head instead.
 

 
 
You've probably sussed this already but at the back there's two vacuum pipes -the one on the right goes through a vapour trap and then to the ECU MAP sensor. The red one goes to the air box and activates the hot air control flap (I believe its called a "Thermatic Valve"). I've blanked this off.
 
You can feed the dizzy vacuum advance by inserting a T piece in the MAP pipe, if required.
 

 
I've also blanked off the three connections at the front of the TBI. I haven't a clue what the two connections are at the base but I've connected them together.
 

 
Hope this helps!

That sir, is a massive help, Thanks!
I also have no idea what the 2 front outlets are for, will look to find out.
I'm not sure if I'm going to have a map sensor, but on the back of yours, it comes out of the manifold into a black box, mine hasn't got that, just the 2 outlets at the back, what's the box?
Did you put it back together with new gaskets? Can't seen to find any!

Thanks again!

[miniBrain]

Hi screech -

 

The box is to trap fuel droplets before they reach the MAP sensor. New ones are about £20 IIRC.

 

The gaskets on mine were in good nick so didn't need new ones. The TBI is a Bosch unit used on older Polo's and other cars. It has the following numbers stamped on the casting 551 46062 - try searching for Bosch parts instead of Mini?

 

Not using MAP? You can use TPS but I understand MAP gives a better estimate of the air mass thus more accurate fuelling. TPS is normally only used for acceleration compensation.

 

Bob

[spiguy]

The two pipe stubs marked unknown, both service breathers. I can't recall which one does which, but basically one goes to the purge valve which opens under certain conditions to allow venting of the charcoal canister under the passenger side wing (which has collected fuel vapours from the petrol tank) and the other one goes to the breather which is mounted on the radiator side of the engine. I have a suspicion that the one on the right is the purge valve one, as it is restricted. Could be the other way round though!

 

The large one marked breather, as you probably already know, goes to the clutch housing breather.