Hey up decided to start a new topic.
So I have upped my req fuel to 13 as discussed with new laptop and recomended USB to serial lead ( the flashing light are cool by the way ;D ;D )
Suddenly I am getting lamba readings of 20 + ( thats twenty not 2.0 !! ) in my logs !!! checked in excel and they are definatly there - still got learn mode on.
I am about to email my logs to dnb and rob just wandering if anyone else has experienced this. Will go and collect some more data
Regards
Agriv8
20 normally means air, overrun fuel cut or severe misfire
You'd know about it if it was missing enough for that.
Have you checked for exhaust leaks upstream and around the sensor. Is the sensor actually tight in the boss? And the sensor is definately wired in and set up correct? And reading lambda not AFR
Sorry if these are all a bit simple sounding, but its often the simple things that catch us out :-\
Yup I often overlook the obvious the sensor is in tight.
there are possible slight leaks in the exhaust will try gunking these up.
looking at the map again an visialising the route i took - it may be that i was go down hill engine breaking could that have an affect ( thinking fuel cut ) if you look at just before the vertical line it looks like injectors have a pulse width of close to 0 ?
here is a screen shot of the log
(http://i167.photobucket.com/albums/u157/Agriv8/highlambdascrdump.jpg)
further thoughts welcolm I am going of to find somwhere to host some files so that people can swap log files easilly.
regards
Agriv8
right found somwhere that does free public access file hosting..
can someone see if they can access the following link to my log from earlier this eve.
http://www.box.net/shared/e1ii2oelyx (http://www.box.net/shared/e1ii2oelyx).
if yes and it would be usefull can write some instructions how to set up / use ect might be useful for people to share maps and logs ect
regards
Agriv8
So what have you got in the low load line of you VE table? If its tiny numbers, and that equates to smaller than the injectors minumum pulsewidth, they're probably not opening. You won't notice beacuse you are asking for almost no combustion anyway, and iff all the cylinder stop burning, the engine turns very smoothly. The encouraging thing is that when the load goes back up, lambda (eventually) comes back to something sensible.
At first glance it looks like a sensible log. Ignition may be a bit retarded (won't know without a dyno though)
How does it feel to drive - any problems, glitches, stumbles, coughs etc etc?
Quote from: Agriv8 on April 26, 2007, 10:48:25 PM
right found somwhere that does free public access file hosting..
can someone see if they can access the following link to my log from earlier this eve.
http://www.box.net/shared/e1ii2oelyx (http://www.box.net/shared/e1ii2oelyx).
if yes and it would be usefull can write some instructions how to set up / use ect might be useful for people to share maps and logs ect
regards
Agriv8
Got it :)
Just looked through the log
You are indeed getting 0.0 injector pulsewidth - overrun fuel cut :) so everything is working as it should.
Those huge lambda spikes look like overrun fuel cut, what are your settings for that? (Settings->Constants)
Rob
rob assume you mean basic settings
(http://i167.photobucket.com/albums/u157/Agriv8/scrdumpbasicsettings.jpg).
as there seems to be nothing under settings constants just in case though.
(http://i167.photobucket.com/albums/u157/Agriv8/vemsbasicsettings.jpg)
in answer to Cliff how its running ?
I know I shouldnt have done it as it isnt mapped properly but unhooked the laptop and took it for a 3 mile blat in a few words if its this good on patched together maps - I am going to have to start wearing more underwear when it does get tunned properly .
the only very slight issues are
Jittery under slight fuel load / throtle load ( but 100 times beter that stock ecu !!! )
loosing my licence as it acelerates so efortlessly nearly acelerated into the back of a BMW M5 when we got into the national speed limit ( and he wasnt hanging about ;D ). must remeber to drop the rev limiter until I get her tuned properly.
in a nut shell defiantly a Murry Walker 'Fanatastic absoloutly Fantastic'
I will try and put together a 'How To' for setting up file hosting as it seems to work
regards
Agriv8
In the basics setting page, see the box 'fuel cut under kPa'? You've got it set at 14, and the MAP is dropping to 2 or 3 in places. The lower down 'overrun fuelcut rpm' and resume means it will do fuelcut any speed above 1700 (and the MAP is below 14), and resume at 1500rpm, regardless of the MAP.
Have a play with these values. My first instinct would be to set the fuelcut rpm up from 1700 to about 2500 so that you don't get fuelcut around town, but depending on the injectors that can make things worse, so you just have to play and see. 1500rpm for resume is about right. 14kPa may or may not be right, depending on the MAP you see on overrun. In your case it gets pretty low, so you could consider lowering this value - maybe try about 8kPa? This might give you better decel control (less of a step change). You can't damage the engine by changing these numbers, so have a play with them and feel the effect on driveability. These are the bits that take time to perfect, but make the difference bewteen a cal that feels like a race car (i.e. full load power only cal) and a road car (proper driveability at low speeds and loads)
But, be a bit careful with your vacuum on overrun. 2 kPa (if thats accurate) is pretty low, and could be enough to start pulling over oil if you are using a returned breather system still. Keep an eye out for blue smoke as you tip back in after an overrun, or pull of some breather hoses and check for excessive oil film. Pulling oil over is bad because it then has to be burned, which lowers the octane rating of the fuel and increases the chance of knock until its cleared. It also puts extra strain on seals (too much pressure difference across them), and finally it also makes you pride and joy look like a smokey old bus ;D
Glad it drives well - well done. Pat on the back i think :)
Thanks cliff,
I can have play later.
rob has sent through the 'thigy whot sit' to go in the injector flyback lead. so a bit of playing tomorow so need to do a few lambda check runs arround the block to get the fueling ok again.
then over to my mates who has a MOT gas analiser just to have a looksie on HC ( and check on lambda readings because I can ) on each bank and do a compresion test on no 8 as gut feeling its not 100% ( hope I am wrong ) . taking it easy and checking logs as I go.
2% kpa could be right'ish I have no bypass valve fitted
just the throtle valve so a v8 under engine breaking has to pull that air through the small gap left for tickover of 1000 rpm ish So adding the momentum of 750 k I assume it could get that low ( trust me under stock ecu it would lock the rears on down shifts Thats caused me a few underpant changes )
RE oil - all the engine breathers vented to a catch tank and then atmosphere. Mainly to stop knock though my compresion is lowish - plenum and intake get hot ( heat soak ) due to the inake nature of the V8 cant do a lot on the last bits but I can remove the oil vapour.
Intake does pull external air
will keep you informed and thanks for your tunning guides - good read.
regards
Agriv8
Make sure that you check the UserGuide for the injector settings.
thanks rob modified the settings as your guide and fitted the diode.
done a few runs arround the block and got Lamba to somthing like.
here a log if i could have your thoughts.
http://www.box.net/shared/itt8c81btx (http://www.box.net/shared/itt8c81btx)
I am off to see if I can sus why I suddenly getting a trigger error ( but I did notice that voltage dropped to 0 - so off to check connections. )
all the best agriv8.
trigger error sorted ( I think ) the trigger feed was laid across the top of a coil pach ( sorted with a couple of cable ties hopefully ).
regards
Agriv8
I can see the error there, at 2842.280s into the log.
Lets start from the top... What are you trying to do its an idea to quantify your goals.
Rob
Made a few more logs will check them errors.
Goal's not sure what you mean.
regards
agriv8
rob been thinking about this question most of the weekend.
and all I could come up with ( feel like its an exam )
Goals, get the car to :-
1) ticking over beter than stock ECU
2) accelerating better than stock ECU
3) get the best out of an engine designed before I was born.
4) to run without the dizzie
So I answers to 1 and 2 already sorted assisted by 4
3) I know 3 is going to take a rolling road session ( somthing that I am going to have to save up for) but as I can know see what the engine is doing ( lambda ) and adjust the fueling to get it as good as I can until I can afford the rolling road and enjoy some of the good weather we are having.
4) even if my spark table spark table is not the best it is likley to be better than the dizzie , bob weights and vacumes ( so the 80's )
So possibly answering the question.
With what I have available aiming to get the lambda as close to 1 across all driving and idle
so in reality wihout the rolling road suspect the clossest I am going to get between .95 and 1.05.
reasoble goal do you think ?
regards agriv8
1) Well thats often taken for granted and the effort involved is underestimated. Gary@APT got a lovely smooth idle on Kev's engine using two cells 200rpm either side of the target idle speed. It worth looking at doing something like that yourself.
2) This will come through getting the right fuel and ignition maps along with the right acceleration enrichments (Tip-ins), you'll find that this improves as the mapping improves.
3) Thats your perogative, personally Id go for a japanese multi-valve engine over an old Buick truck engine :P
4) Have you looked at any of the spark advance curves that the old bob weights used to give, are there any around? If so you'll at worst be able to mimic them with a higher level of accuracy and steadyness than the sloppy dizzy could ever give. Either way you should be able to start with a "known good" ignition map.
Driving around on your own using datalogs to record the lambda against MAP (or TPS if your on AlphaN) and RPM will allow you to get close to 1.0, but slowly. Quicker still would be to have someone drive, holding the engine at a steady state slowly building RPM so that you can map live.
The key bit is to experiment, log everything and keep saving your tables - dont be afraid to put your maps to one side and try something radically different.
Now you have the transient voltage diode in your flyback you'll find that your VE table (if you're using Speed Density) will become really quite flat.
Try a bit of AlphaN tuning see how you get on with that.
Read Jorgen's Tuning sessions:
http://www.vems.hu/wiki/index.php?page=TuningSession%2FClosedloopTuning
http://www.vems.hu/wiki/index.php?page=TuningSession%2FOpenloopTuning
1) Certainly possible. I found the Rover stepper could be set up well with the PID controller, and along with ignition advance idle control and careful mapping - I had a map row at 500 RPM (that occasionally gets used when Nic drives the car!!) and at 1000. This was good enough with a sensible ignition map to get a very stable idle. The transient diode helps with this too!
2) Couldn't agree more with Rob. It seems the Rv8 responds well to accurate fuelling and quite a bit of timing advance. You can also get good economy!
3) Some of us like the old Buick truck engine. ;) I remember when Rob first drove the Griff... He wasn't quite expecting it to be like it was.
4) I have the timing profile for the TVR bob weights. They're far from ideal as the dizzy was very compromised to stop det at higher RPM. You can do much better even if you are conservative. Rovers seem to like lots of timing at part throttle. (I think I sent you my timing map in my MSQ file. It was based on the dizzy weights - it's the conservative version but it should give you some clues)
I favour a lambda of 1 for idle (emissions) but lean it off to around 1.05 for low MAP value cruising. I aim for 0.86 on acceleration (ie high MAP values in the map) and use the tip in (acceleration enrich) to remove the lag inherent from the way speed-density works. I found that I had to add quite a lot of fuel for acceleration, but then 5 litres isn't exactly a small engine. You can get lambda VERY accurate without a rolling road. It's only timing you can't do easily on the road. (I was lucky enough to be working north of London at the end of last year - I got LOTS of tuning done :) )
Thanks Chaps, Just what I wanted to hear.
dnb running your spark map and its lot happier on that - than the 'evil Dizzie'.
Still not running a Stepper as have a feeling it would only add another ? into the equation ( I can get confused easy enough ). My feeling is Ill add one if needed to assist with tickover.
Rob
mapping on the fly didnt think of that
Wanted V8 test pilot ( must have a steady right foot ) size 13 feet and 38 inside leg :D
Seriously I have a couple of mates ( who I trust ) who could be the wheel man.
Regarding the V8 yup it does not make sense especially in a 750 kilo car but it floats my boat ;D
Many thanks for all the help you have given me a few 'areas to look at'
Agriv8
I'm pleased my spark map is OK for you :)
On the fly mapping is great. Nic got very good at holding the car in a load cell in the end.
Quote from: [email protected] on April 30, 2007, 08:43:51 AM
The key bit is to experiment, log everything and keep saving your tables - dont be afraid to put your maps to one side and try something radically different.
That is one of the best bits of advice that anyone can give. Record keeping is absolutely critical. But if you are meticulous about it you can try radical changes, safe in the knowledge you can always step back to a known 'good' state.
Quote from: dnb
I favour a lambda of 1 for idle (emissions) but lean it off to around 1.05 for low MAP value cruising. I aim for 0.86 on acceleration (ie high MAP values in the map) and use the tip in (acceleration enrich) to remove the lag inherent from the way speed-density works. I found that I had to add quite a lot of fuel for acceleration, but then 5 litres isn't exactly a small engine. You can get lambda VERY accurate without a rolling road. It's only timing you can't do easily on the road.
That's about right. For catalyst cars that only need to pass MOT or SVA emissions I'd consider setting the idle and low load line up to 3000rpm at a target lambda 1.02 (reduces HC and CO emissions, which is what they test for). You can get fuelling right through just driving about, but ONLY if you take logs of all your drives. This applies for start and warmup compensations too. You will find however that you change you driving style to hold the car in different load 'steps' (i.e. engine accelerates along a constant load line in the table).
Quote from: Agriv8 on April 30, 2007, 11:36:13 AM
mapping on the fly didnt think of that
Wanted V8 test pilot ( must have a steady right foot ) size 13 feet and 38 inside leg :D
Seriously I have a couple of mates ( who I trust ) who could be the wheel man.
Regarding the V8 yup it does not make sense especially in a 750 kilo car but it floats my boat ;D
Many thanks for all the help you have given me a few 'areas to look at'
Yep, you need a man (or woman) who is not a fool when in the car, who'll be more interested in helping than acting the prat. Once you have that you're part of the way there... Long slow sweeps up the rev range with varying levels of urgency!
But you wont need a wheel man to get your idle creamy smooth, just some time. And some experiments - for example make a map up thats almost completely concentrated in the idle area RPM: 500, 600, 700, 800, 900, 1000, 1100, 1500, 2000, 4000, 5000, 6000. Kpa 25, 30, 35, 40, 45, 50, 55, 60, 70, 80, 90, 100. Flatten the advance out to your idle value right across the table, and do the same with the VE that gives you close to lambda1 at tick over. You'll have so much resolution to play with that you'll get a feel for whats needed.
When you reload your original map you'll be able to work out what range you're idle settings will be and will be able to configure the cells accordingly.
Nothing against V8s every boat should have one! ;D Just not enough valves to excite me! I'm hoping that we'll be seeing a 'proper' V8 appearing in the Projects section soon :P
And yeah idle control, its exactly that - another ? in the equation that makes for misery and upset 'till you need it dont use it!
Start with it shut off and get the car to idle nicely when its up at its operating temperature, and accept that you're going to have to blip the throttle when cold to stop the thing from dieing.
Then once you have a nice stable idle then add complication.
Quote from: [email protected] on April 30, 2007, 02:12:25 PM
Nothing against V8s every boat should have one! ;D Just not enough valves to excite me!
We've got as many valves as your Datsun has... ;)
What new v8? One of those nice little ones with 5 valves per cylinder?
Quote from: [email protected] on April 30, 2007, 02:12:25 PM
But you wont need a wheel man to get your idle creamy smooth, just some time. And some experiments - for example make a map up thats almost completely concentrated in the idle area RPM: 500, 600, 700, 800, 900, 1000, 1100, 1500, 2000, 4000, 5000, 6000. Kpa 25, 30, 35, 40, 45, 50, 55, 60, 70, 80, 90, 100. Flatten the advance out to your idle value right across the table, and do the same with the VE that gives you close to lambda1 at tick over. You'll have so much resolution to play with that you'll get a feel for whats needed.
Rob reading between the lines her ( or making it up as I go along ) are you saying that I can configure VEMS to create a table with the reference points we think are important ( or to put it another way
More detail )
So a table that look like
RPM -->500, 600, 700, 800, 900, 1000, 1100, 1500, 2000, 4000, 5000, 6000
MAP
|
v
25,
30,
35,
40,
45,
50,
55,
60,
70,
80,
90,
100 |
are there Instuctions anywhere to create and upload the table ?
--- > Mental note to switch learn off
I can create this New 'Start point' from my existing table
RE the V8 Must be one of those VAG ones
Just had a look at one of the ve tables I had saved.
will have a play and possibly another How to coming up.
regards
Agriv8
Its more of a case of giving yourself more detail for the area of the map that you're interested in configuring.
Then you will find that theres theres redundancy of information in some of the mapping points, so you can remove them and still have the smooth idle you like.