Time for an update about 1-2-squirt..

Doing over 1000km on lpg now; injected by 1-2-squirt and fired by 1-2-spark
and still improving..

Yesterday I discovered by accident, why it mis-injects when I hit the blinker or horn. It seems that the cable which feeds the 1-2-squirt with the rpm coming from the 1-2-spark unit attracks a lot of noise.... Infact when I put my finger on the connecter of the 1-2-squirt wire is taking the rpm from the a coil which is running nearby.. So after adding few resistors this is now gone... Only the horn is still a little problem, but now I know where it comes from I can cure it for sure....

So what do I have sofar....

crankingenrichment:


If you start the engine it needs extra fuel you can adjust it here, again by temperature and and treshold... I'm giving crankenrichment up to 400 rpm and it starts like a charm... cold or hot....

coolant-temperature:
A cold engine needs more fuel then a warm engine, you can adjust it here



Inlet air temperature:
Here the airtemperature is measured from the air which is going into the engine]
colder air needs more fuel (thicker) then hot air (thinner)


ofcourse the map-sensor I had already with 1-2-spark connected to the rpm, I have a true 3D 12x12 fuelmap... Lateron I can make 16x16 out of it but for now it works great already..



So insted of tweaking the carburator, changing jets or fiddling the iddlejet, I just need to adjust the numbers of the cells in 1-2-squirt...

Higher numbers means more fuel, lower numbers meaning less fuel...


So now on to the next challenge... acceleration injection....

I have my own thoughts about that...


The chip is steadily measuring and calculating and executing the above in a loop... so once every loop I will also measure the diffrence between the map-numbers. When this is higher then a certain theshold acceleration will come in..

I will make a 6x6 table kpa/sec against coolant or air-temperature and look if it works....



The only issue is I'm rumming out of memory space again... So I need to switch to a bigger and maybee faster chip...

Geo

I see a potential problem in reading "acceleration" conditions from MAP values: MAP readings aren't quite stable, especially at idle (like for a quick takeoff with extra enrichment). Normally I think you got rid of that using "maplagfactor" for a smooth reading for 1-2 spark, now I'm afraid this quick pulsation at idle will be read as big differences, so it might generate "false positives" unless that treshold is really high, and it only squirts extra fuel when you really floor it and MAP readings goes way towards 1.
Other that that, this is awesome work - nicely done! I'm quite happy with my carb + 1-2 spark combination (might tweak it a bit now that the carb is fully renewed), but I'd like to see how it does for fuel efficiency

@Saurus, several people are driving there 2cv's without a throttle-position sensor... Lars, myself and some others, so with megasquirt it is possible to do acceleration enrichment based on map...

So I'm going the same route with 1-2-squirt....... we will see...

Also, much more drive without TPS, only with idle and full-load switch on throttle...

Practically all cars what have Jetronic injection, only exception what I have found is D-Jet with its own special "pulsing TPS" for accelerated enrichment and idle switch, full-load has own sensor by pressure switch...

Time for a little update about 1-2-squirt. I have now driven about 2000km (some 300km+ trips) at 1-2-squirt and it isn't running bad at all (some where happy if their 2cv was running that well on a carb )... Last week I found a little bug in the software so again there is improvement in the overall behaviour...

It starts very well cold or hot and also theres no running lean or rich over a long period, it is always the the same.. Looking at iddle it it also behaves the same (mostly to rich) but it doesn't starve...

So it is time to programm acceleration enrichment..

I will start with mesuring the diffrence of the inletmanifold pressure between 2 revelutions
if the diffrence is bigger then a certain threshold (to eliminate noise) it wil be looked up in a table (rpm vs map-diffrence) which gives an extra opening time to the injector, creating acceleration enrichment.

This value will first go to another table of the coolant temp giving more or less opening time of the injector (cold or hot engine) just like I already do with airtemp compensation or coolanttemp compensation I think I will get a proper acceleration enrichment this way...




I think I will start with an rpm based (time) versus inletmanifold pressure diffrence (map) and see what happens...

I made a little note for my self (as I mostly do) so take a look...

The mad scientist is back at it, working of 1st principles and writing in English for us all!
Nice work Geo!

Did a first run with acceleration enrichment build in... Programmed some numbers into the chip..

So what did I do.. Every revelution the inletpressure is measured and subtracted with the pressure of the last revelution (take a look at my post above)..

Now if the diffrence of pressure is bigger then a certain threshold (in my case 20 millibar to eleminate noise) acceleration enrichment kicks in..

I made a very simple start just to look if it works,,,

if mapdiffrence < 50 millibar the injector will be open longer for a stagering 0.001 seconds
if mapdiffrence < 100 ==> 0.0011 sec
"" <150 ==> 0.0012sec
200 = 0.0015 ms
280 = 1700 us
380 = 1900
530 = 2300
700 = 2700
850 = 3000
1000 = 3000

1000 millibar is outside airpressure


Does it work??? Yes it does, VERY WELL..... When I hit the pedal normally the engine would do nothing for a moment or 2 and then pick up..

Now it acts as a normal 2cv, only giving a short time to responce (1/4 of a second or less), but this is normal for a fuel linjected car.. (My opinion is a carburretor has a faster responce then injection when opening the throttle)

I've build in that the red eror led lights up when acceleration-enrichment kicks in and you can see it really light up when hitting the accelerator.

I will make a video of this one of these days.....

So at the moment I have a injection system which is (almost) as good as a normal 2cv is..


Another problem is, my chip is running out of memory, (I'm now at 98%) so need to find a solution for that...

To be honest, my injection runs better then Megasquirt (never could programm a decent acceleration enrichment with Megasquirt) but hey it will be my poor tuning capability..

Next is to make my software that I can handle acceleration enrichment and finetune it.....

To be continued.....

Processor's
https://www.microduino.cc/module/view?i ... 00003ede53

A little update from 1-2-Squirt.... My car is still running at 1-2-squirt all the time, didn't run at Petrol for over a month now...

I've implemented a simple acceleration enrichment but it is working very good, better then I ever managed on megasquirt.. I tried to immitate a carburator, when you hit the throttle a squirt of petrol is squirted into the carb. As longer as you hit the throttle as longer the squirt lasts and more fuel is going into the carb. Now I'm doing the same (well sort of)..I sticked to the notes at the last page...


At the moment I'm stuck, I want to squirt into the manifold when the inletvalve is closed so about 90 degrees after TDC... You can realy feel power increasing when I do this but the microcontoller gives me a lot of hick ups doing this. I'm now trying for a week to get this done but it doesn;t work......

Hope I can manage it befor going to Poland otherwise I drive on 1-2-squirt as it is now...


p.s. the engine starts better when squirting at 45 degrees befor TDC I would never believe the timing of the squirting would have such an impact...

Hi Geo,

great to hear you managed to get this far! I'm very keen to see your inventions in Poland!

I'm just thinking out loud now, and not really familiar with squirtstuff, but wouldn't it be better to have 2 sensors for determining of the crank speed and angle (similar to visa 652) it's just a thought..

oh, and can I pre-order a 12-squirt already love your 12-spark so much, I NEED 12-squirt as well!

greetzzzzzzz, Rusty