Siamesed Code Trial
Turbo Mini Forums

Do you want the good news or the bad news? Well, the bad news is that I could not get the code to work as intended. The good news is that I go it to work another way.

I initially set it up to fire the injectors twice per cycle into each port as intended by Jean. However, whatever timing I put on the injection, I could not get the cylinders to run anywhere near equal AFRs at idle. My theory is that the second pulse that sits in the port until the inner cylinder valve opens, starts to evaporate, displaces the air and then burns rich.

The best it ran was when the injection point was approx. 80 deg BTDC, but the car was not driveable.

So I then set the car up ala MPi. Firing the injectors once per port per cycle, alternating.

I saw an immediate improvement. I used timing figures similar to those shown in TDs log of the MPi last year.

After a couple of short runs and tweaks to the map it felt good enough to do a logging session. Extract attached.

http://www.jaservices.co.uk/photos/Dual%20...EFI%20Siam1.pdf

There is a long way to go to get the map right so that it gives equal AFRs across the range, but there is nothing that cannot be achieved.

The only down side to setting it up in this fashion is that you cannot stage in additional injectors as originaly intended. The two injector drivers are working at 360 degrees apart. You would need four injector drivers to use alternating and staged injection.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Sorry Paul for being so obviously naive, but when you say "twice per cycle into each port" and later "once per port per cycle alternating", I am confused...
To me a cycle is two engine revolutions but with a normal VR (or similar) sensor on the crank you can only measure one engine revolution, you need a cam pick-up for "per port per cycle" counting ???
I'm sure to be shot down in flames for this post but I can't understand what I've read yet !!!

Sorry,

Rod.

Schrödinger's cat - so which one am I ???

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

I think the plan for tomorrow must be to revert back to the firing of each injector twice a cycle.

I'll see if I can get some datalogs on a variety of fixed injection timing settings to see if there is a way forward.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

one thing paul is that you are efecting a change ,so thats good .

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Dum question but can you use a cam position sensor with MS? it's got to make life easier hasn't it?

EDIT: I meant MS not MJ

Edited by Rob H on 3rd Feb, 2008.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Edited by Rod S on 3rd Feb, 2008.

Schrödinger's cat - so which one am I ???

We have been logging all day!

Started by setting up the injectors to fire twice per cycle, once per rev as intended by Jean.

I also disabled EGO control as it was interfering rather than helping at this stage. It will be useful as a trimming tool once we are sorted.

Instead of the table, we started with fixed injection timing, initially at 30 degrees before TDC.

I checked the injection pulse with my timing light and can confirm that the code is doing exactly what it is designed to do.

At idle the AFRs were far apart, but seemed to close up if I revved her.

We then did a log, lowered the setting by 10 degrees, did another log and so on until we got to 10 degrees after TDC and then realised that we were going in the wrong direction.

After lunch and time for the laptop to charge we did logs at 50, 70, 90, 110, 130, 140 and 150 degrees before TDC.

The last two logs were not really useful because the laptop started playing up due to low battery. By then we had the laptop talking to both the MS and the Innovate stuff to ease changing the settings, but it drained the battery very quick.

I think we may be getting somewhere at the higher values.

The attached log shows full throttle at the 130 degree setting. We are finding it difficult to find a point where the AFRs are equal and maybe due to wall wetting we never will, but we seem to be making some progress.

http://www.jaservices.co.uk/photos/Dual%20...Log%20Siam2.pdf

The biggest problem is that my oil leak from the primary gear has re-appeared big time due to having lost the breather take-off on the carb. Despite hooking up a vacuum to a temporary catch tank, it's peeing out and the clutch is now slipping.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Log at 150 degrees attached.

I've only just seen this as I do the driving, but I'm encouraged by it.

http://www.jaservices.co.uk/photos/Dual%20...Log%20Siam3.pdf

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Good stuff!

it seems like the afrs are staying a similar amount apart through out the rev range.

logging snigger...

Good to see you're making progress. And I'm glad to read that the code seems to be doing what it should. Even though it was working on the bench, there are always things you can't foresee or reproduce on the bench.

It might be that the simple solution is not going to be precise enough because of wall wetting. That would mean having to go to a cam sensor and using different pulse widths for inner and outer cylinders and/or different injection timing.

And I would think that your setup is pretty close to the optimum in terms of minimizing wall wetting issues. So if you can't find a setting where AFR differences are minimal then it's not very likely that others would either.

Keep up the good work. I'll try to see if I could make a few minimal changes to the code to go to sequential or if I need to make major changes to get it to work.

Jean

http://www.jbperf.com/

Thanks Jean,

I think that main limiting factor at the moment may be the maximum advance of 180 degrees.

It may need to go higher than that at high vacuums.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

I'll have to check but I don't think there is a real limit in the code. It's a limit set in Megatune with the ini file. If you change the limit to go up to 360, I think the code will still work.

Like I said, I'll check the code but you can give it a try in the ini file.

Jean

http://www.jbperf.com/

Hi,
Not sure if you know this or if it will be any help, but each MPI injector is connected to the ECU twice????
I could take a look in the ECU to see if there's any clues in there?
Cheers,
Gavin :)

VEMs Authorised Installer / Re-seller. K head kits now available!

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Visit www.doyouneedabrain.co.uk

My Mini build diary

Edited by Paul S on 3rd Feb, 2008.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Hi,
I wondered if they were linked inside the ECU?
Cheers,
Gavin :)

VEMs Authorised Installer / Re-seller. K head kits now available!

WB/EGT gauges. Click here for customers write-up

Visit www.doyouneedabrain.co.uk

My Mini build diary

ref wall wetting ,
a way to reduce this may be to run a higher fuel pressure and a smaller injector ,

or perhaps an injector designed to provide a finer spray eg the 4 hole ones ?

another thought is the scatter am idea ,which might have a big effect in this sit .

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

Edited by jbelanger on 3rd Feb, 2008.

http://www.jbperf.com/

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Edited by Paul S on 4th Feb, 2008.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."