Req_fuel & injector settings

[pete95zhn]

We were looking at this and one thing sticks out. You wrote: WUE is flat 140% from -40C to +5C, then linear to 0 at +70C.

We argue about what this means but I get the impression that you have 0 in the 70C cell. That means that you remove all fuel and that the engine only runs on some end of scale rounding error.

You should have 100% in the 70C bin. That means that the warm up enrichment is turned off.

Jörgen

Sorry, misprint, it should have read 100%, that's what's in that cell.

[pete95zhn]

Its clearly chucking more fuel in, else you wouldnt get black smoke out...

Please download your configs and tables and send them to me.  What Firmware are you running?

Rob

Firmware is 1.1.24. Config & tables ( although for batch fire ) can be found at my Wiki memeber's page http://www.vems.hu/wiki/index.php?page=MembersPage%2FPeteKrgr. Latest ones I'll send tomorrow.

[pete95zhn]

Failing the full config and tables can you post a picture of the the warm-up enrichments.

E-mail sent.

[Sprocket]

http://www.vems.hu/wiki/index.php?page=MembersPage%2FPeteKrgr%2FConfig

Areas i would be looking at


tps_low=22

tps_high=FF  Both these need calibrating for the TPS sensor, is your sensor really 255 at 100% WOT??

[Sprocket]

Oh and if you are running batch fire the table generator will be miles out. The numbers it seems to produce are huge in relation to what is actualy required.

Knock back the VE values where you are having the problems.

You could try the VE learn mode and set it agressively so that it pulls the VE values back quickly.

[pete95zhn]

Oh and if you are running batch fire the table generator will be miles out. The numbers it seems to produce are huge in relation to what is actualy required.

Knock back the VE values where you are having the problems.

You could try the VE learn mode and set it agressively so that it pulls the VE values back quickly.

No, I'm not running batch fire anymore. I will correct tables to Wiki later. I had to go and re-calibrate the TPS again, that 255 wasn't right. I remember I had something like 224 and it now gave 215 at WOT and still 34 at closed position, TPS clicks when closing. Should it be 0 when fully closed?

EDIT: There seem to be one real and big mistake, ie. duration of acceleration enrichment. I have set it to 25 ms but now I was told that there's misprint in MegaTune and it's really 25 s, so no wonder why it runs very rich while trying to move the throttle...!!

[Sprocket]

Even if your not running batch fire, the table generator still returns huge numbers

Looking at the VE table on your Wiki page your VE at idle is around 40 and in the part throttle mid RPM range its 128, that is a very large hike, if you are over fueling, this i feel is the area you should be looking at.

Also, low ohm injectors with the resistors require a reasonably lagre ramp up time. I recon this is playing a major part in increasing the flow rate of the injectors with them being sluggish open and close. I suffered similar problems when trying to get my engine running and the VE table was miles out!!! almost double!! The injectors and the resistors work and work well, you just have to tune for it.

[pete95zhn]

This is the current VE table:



I have to correct these too to Wiki too.

EDIT: I have to correct these too to Wiki, but only after they're more correct. This table gives 12:1-14:1 idle

[Sprocket]

Your engine idles at 50 kpa?

[pete95zhn]

Your engine idles at 50 kpa?

Yes, unfortunately...big valved head ( 48mm in /45mm ex ) etc. No found leaks, though. Before modifications idle kPa was around 35-40.

[[email protected]]

Personally I'd have a line below idle at 40kpa.
I've got your setup and will do some tests later.

Rob

[pete95zhn]

I noticed one peculiarity when looking throuhg one datalog with MegaLogViewer. There reads " Fuel Pressure 5 bar". Where does it get that figure? I'm using 3 bar and if the box really thinks that used pressure is 5 bar, it's really significant difference and IMO causes short PW ( thus requirement to use double req_fuel ) with other given numbers being accurate.
I haven't noticed either any field with aquestion of used fuel pressue or requirement to use fuel pessure sender. Is this 5 bar pressure some kind of basic setting in all firmwares or can it be changed? Or just MegaogViewer error?

How about divider then? I have all the time used Divider = 1 with both batch & sequential fire, but here's a 2.3l turbo Saab with almost similar VEtable, injectors and boost but he's running batch with Divider = 2 and req_fuel 4.1 ...

[Sprocket]

With batch fire and a divider of 1, all the injectors fire every engine event, 4 times per cycle. setting the divider to 2 will halve the injection events resulting in the injector firing only 2 times per cycle, but the injector squirts twice as much (required fuel value is doubled).


One thing i am unsure of is what the required fuel calculation is calculating a figure for. I think it is a figure for sequential injection where the injector fires once per cycle, if you then decide to run batch fire with a divider of two, i would think the required fuel value should be halved, or batch fire with a divider of 1 the required fuel value should be halved and then halved again. This however, depending on how you have sized your injectors will determine how big or small the pulse width is. If you sized your injector to be big enough to provide all the fuel in one squirt (sequencial), the same injector will be massively oversize when running batch fire with a divider of 1. If your calculated required fuel pulse width is already small, running batch fire with a divider of 1, the pulse width will be quarter of that, and idling will be problematic????

There is no reason not to run sequential injection, as long as you have wired the injectors to individual output channels on the ECU.

The required fuel value is the figure the algorythms use to determine the injector size, thus it can determine the size of the pulse width to provide the required fuel for the current operating condition.

This theory is a little unclear and i cannot find anything in the Wiki about it. Needles to say, i was untill recently running a divider of 1 on what would be concidered batch fire, i had to halve the calculated required fuel value. after some thought and a little experimentation, I now run a divider of 2 and i now use the calculated required fuel value, with the VE values the same, still achieving the same fueling

I hope i havent confused you too much, LOL :D if i have, just ignore what i said, lol, im just brain dumping :D

[Sprocket]

Ignore the fuel pressure value.

If you have no fuel pressure transducer, then the ECU will not be reading anything.

[Jorgen]

Hi,

It sounds like your setup is messed up. I would normally have sent you a config that would get you started but as you use the auditrigger setup in an unsupported application I don't have a setup for you.

Could you post config.txt, tables.txt and the msq from the megatune you are running?

We all prefer to look at the setup in different ways and if you prepare a fresh package with all of them you will be more likely to get someone to review and find the problem of your setup.

It's not unlikely that your problems are related to the Porsche trigger.

Jörgen