Help tuning my EMS please

[astondg]

I have posted on here a few times about the standalone ECU I got fitted to my E30 323i (standard M20 2.3L with exhaust and 6 branch), it is an EMS Stinger. Since I got it fitted the car hasn't been running too well, especially when it's cold, and it seems to be using a lot more petrol than it used to. It used to use about 9L/100km (31mpg) when I first got it, now it uses about 23L/100 (12.5mpg) which is more than a lot of big old style pushrod V8's use (like the ones in the Holdens and Fords out here) and I'm actually not sure how it is getting that much petrol through the injectors and using it in the engine, it's only a 2.3L and with small injectors. I also noticed that on my last tank of petrol which was used for around town driving I got worse petrol consumption than the tank before which had around town driving and autocross racing, I'm not sure how that happened.

The ECU uses a MAP sensor so the AFM has been removed. It doesn't have a lamda sensor because the mechanic said they would be about AUD $400, I presume he had one fitted to the exhaust when it was tuned on the dyno. He did mention something about me being able to see the A/F ratios though so I thought maybe the ECU tries to work it out or something but as the datalog below shows it doesn't seem to.

I'm not sure how I can show you all the tuning but here are some tables for the ignition and fuel maps. I only just got a laptop so I haven't really done any dataloging yet. Also without the A/F I couldn't really tell much in a datalog anyway. I can export the whole ECU file and then send that and the ECU software to you if you want, it only seems to work on a laptop though and not my desktop.

Anyway could someone who knows about ECU tuning have a look and see what they think? I don't have a dyno sheet yet but I will try to get one soon. To start with I was hoping that someone could just have a general look and see if anything majorly wrong with it. If you want to to get a datalog I can, not sure how to get it to you though because there is no option to save or export it and it won't let me select the table of values that it collects so I can't copy them to Excel or something.

Finally, does anyone know where I can get a cheap lamda sensor (wideband is better right?)?

Fuel Map: http://www.members.westnet.com.au/astondg/FuelMap.txt
Ignition Map: http://www.members.westnet.com.au/aston ... ionMap.txt

From the setup screen:
Static Timing: 10.00 Deg BTDC
Percentage for cold crank: 43.20%
Dwell mS: 3.50 mS
Injector Ohms: 10 - 16 ohms
Injector Time Scale: 40
Acceleration Enrichment: 25.60%
Enrichment Duration: 20
Soft Rev Limiter: 6650 RPM
Hard Rev Limiter: 6700 RPM
Deceleration fuel cut: Not used
Use Throttle Sensor option is unticked so does that mean it isn't using a TPS?

Thanks very much,

Aston

[Ant]

For the wideband try innovate in the US, they do the LSU4 and controller package for $200 iirc

the top value on your files, I assume this is RPM ? kpa vs rpm/advance ?

it would help if you labelled the scales dude what do the values in the table mean ? fuel expressed as PWM, or %

questions questions

[astondg]

For the wideband try innovate in the US, they do the LSU4 and controller package for $200 iirc

Ok, thanks.

the top value on your files, I assume this is RPM ? kpa vs rpm/advance ?

it would help if you labelled the scales dude what do the values in the table mean ? fuel expressed as PWM, or %

I have no idea otherwise I would have labelled them . The manual says "There are 11 load points every 500rpm. 9 points from -80kpa to 0kpa and 2 points in Boost. First at +75kpa and second at +150kpa." So I guess that is the kpa bit? Then it says "Throttle Position Load Point. Starting at 0 through to 12,500rpm. There are 11 settings per 500rpm at 10% increments. These settings represent a percentage of throttle opening from 0% to 100%" but then it talks about the TPS which I'm not sure we have? Does it need a TPS? Just that when I tried a datalog the throttle position stayed at 100% the whole time, even when it was idling by itself. Also all those are 11 points, the numbers on the table go up to 12 in 0.5 increments. Th only thing on the screen labelled 0 to 12 like the table is the RPM guage (tachometer or whatever) so maybe it is RPM (divided by 1000)?

I think the values in the fuel table seem to be the same as those labelled as injector mS when I datalog so are they the opening times of the injectors in mS? The values in the ignition table seem to be the same as those labelled as ignition advance when I datalog so are they the ignition advancement in degrees? Although are those numbers a bit high for that?

questions questions

That's how I feel but I'll do my best to answer yours so you can answer mine .

Maybe I should go and see the mechanic and get hime to explain it to me and then come back here and try again? I'll see if I can do that, except he never has time to talk to me so it might be 3 or 4 weeks before I get to see him.

Thanks,

Aston

[Jos]

Might understanding of wideband lambda is that it can monitor and adjust at WoT (Wide open Throttle) whereas normal lambda sensors can only measure up to WoT. So yeah wideband is better overall, it increases the scope that the air/fuel mix can be monitored/adjusted.

Large possiblity I am wrong on this

[astondg]

Thanks Jos! I thought it gave more tuning ability but I didn't know why. Now I do .

Anybody have any ideas on the tuning? Do the tables look ok? What about the settings?

I was wondering about this one "Deceleration fuel cut: Not used" what does that do? The mechanic told me he was going to leave the injectors running slightly on no throttle to help cool the engine, is that what that option is about? If it is I might try turning it on to see how it affects the petrol consumption.

I have heard that the Zone chips raise the RPM limit to around 7000rpm, is this right? Is it worth reving that high? After the tuning of mine the mechanic said that the power was about 5800rpm and it does feel like that so I am changing gears before 6500 (usually around 6000rpm). Where do the Zone chips make their power?

Aston

[Boots_Walker]

hey aston have you gotten anywhere with it?

thats some pretty shitty fuel consumption, sounds like its probably running really rich during cruising. if your mech installed a narrowband O2 sensor you should be able to tell if its running rich/lean during light load

the main difference between wide and narrowband O2 sensors is that the narrowband can only tell you if you are richer or leaner than stoichiometric (14.7:1) but not by how much. a wideband can tell you the exact A/F ratio at any given time. is there a reading for o2 or lambda voltage anywhere in the software?

we dont have a proper throttle position sensor unless your mechanic installed one - sounds like he didnt. if its reading 100% all the time maybe the engine is thinking its under full load all the time which would explain the fuel consumption... but i would expect it to run like total shit if that was happening so maybe thats not the case

regarding revs, our motors have single valve springs which are supposed to be good for about 6400rpm, i dont know high high you can rev on them but i wouldnt be wanting to go much past 6500 just to be safe. shouldnt be a whole lot to be gained by going past 6000 anyway

[astondg]

Thanks.

I haven't got any further yet but I have found another couple of places that said they could check it out and possibly retune it for me so I think I will take it to one of them. The only problem with that is it will cost AUD $100 an hour on the dyno and they want it for a day or two so I can't imagine how much it will cost and I don't have a lot of money right now.

I don't think the mechanic installed a TPS so the reading is probably just defaulting to 100% and not being used. I don't think he installed a lamda sensor either, he said they cost too much. I guess he used one of the sensors that the dyno places have and put in the exhuast while he was tuning it. When I datalog the A/F stays at 16 the whole time which is probably a default like the TPS. So unless I buy a wideband lamda sensor I can't really tell much anyway .

Thanks for the info about the rpm.

I just went back to the track recently and I noticed that it felt like it pulled ok out of the corners but then when I got onto the straight it felt a bit flat over about 4500 or 5000rpm. Also I went to about 6500rpm a few of times and it was ok but then a couple of times when I got to about 6000rpm it seemed to fall off, a little bit like it hit a soft rpm cutout. Not sure what that was.

EDIT: Also I think the idle is wrong, when it is cold it idles about 400rpm (and would stall if I didn't hold the throttle on), then when it is warm it idles about 800 to 900rpm, but when it has been driven for a while it idles about 1200rpm. I can't see any option for the idle in the software so how is it controlled? Is it part of the map, like a combination of ignition and timing?

Aston

[ian332isport]

Hi Aston,

I'm not sure if your EMS can operate a Wide band lambda sensor, but you can get them reasonably cheaply from Tech Edge in Oz. Lots of good info here:

http://wbo2.com/lsu/sensors.htm#lsu

Deceleration fuel cut is very common these days in factory management systems. It basically means that the injectors stop firing when the throttle is fully closed, but you are still travelling above a certain speed. Once the speed drops below this setpoint, the injectors will start firing again to keep the engine running. It's purely used to improve fuel consumption (and reduce emissions). There's basically no point injecting fuel if you are coasting down a hill for example.

I'm not sure what different maps and correction curves you have in the Stinger. I know from previous work with Weber Alpha management system that as well as the main fuel and ignition maps, there are a load of correction maps available. There was one for cold start, that monitored the coolant temp, and changed the fuel and ignition accordingly to give good cold start/run characteristics. There was also one that added extra fuel if you snapped the throttle open (worked a bit like the accelerator pump in a carb). You often find that people don't setup these correction maps, and the engine runs horribly when you deviate from the main map.

Ian.

[astondg]

My EMS is supposed to handle wide band lamda, obviously I haven't tested that yet though. Thanks for that link! I didn't know about that place and I live here . That is the sort of pricing I could afford but I have no idea what type of sensor I need, there are a few there. I guess I'll have to do a bit of research.

I am thinking about trying that deceleration fuel cut to see if it helps the fuel consumption. The reason the mechanic gave for not using it was to help cool the engine when we go racing but it never gets over 1/2 on the temp guage anyway, even before the new ECU, so I don't think it needs it.

There are corrective maps for it. One for different coolant temps where ignition and fuel can be changed although only the fuel map has different values, the ignition is empty. There is also an option for the throttle snapped open but that is just 2 settings, one for how much extra fuel to add and another for how long to add it. There is definately a problem with cold start/run so the corrective maps probably haven't been done right. I did take it back to him a couple of times to get that fixed but it still isn't right.

Thanks very much for the response Ian.

Aston