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 8604 Posts Member #: 573 Formerly Axel Podland |
14th Mar, 2009 at 01:49:30pm
Not completely ran out of ideas. I'll try the following.
Edited by Paul S on 14th Mar, 2009. Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
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 (2)[/url] by [url=https://www.flickr.com/photos/150672766@N03/]Rod Sugden[/url], on Fli) 5988 Posts Member #: 2024 Formally Retired Rural Suffolk |
14th Mar, 2009 at 01:57:03pm
Email me the msq (before you make the changes above, ie, today's msq), I'd like to see how it looks on the JimStim and scope.
Schrödinger's cat - so which one am I ??? |
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8604 Posts Member #: 573 Formerly Axel Podland |
14th Mar, 2009 at 02:10:21pm
Email on it's way to your gmail address.
Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
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1267 Posts Member #: 831 Post Whore Montreal, Canada |
14th Mar, 2009 at 02:14:29pm
Paul,
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5988 Posts Member #: 2024 Formally Retired Rural Suffolk |
14th Mar, 2009 at 04:21:30pm
OK, not too scientific yet...
Schrödinger's cat - so which one am I ??? |
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5988 Posts Member #: 2024 Formally Retired Rural Suffolk |
14th Mar, 2009 at 04:27:13pm
I've noticed you have your pulses set to timing tables (which I expected) but trigger point, mid pulse...... What was your logic as you are spreading the timing both forwards and backwards.
Schrödinger's cat - so which one am I ??? |
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8604 Posts Member #: 573 Formerly Axel Podland |
14th Mar, 2009 at 04:29:56pm
On 14th Mar, 2009 jbelanger said:
Paul, Maybe one thing to check is if there is an air leak in one of the exhaust branch. If air can get in it will throw the readings off. Have you tried the single pulse like you wanted? I don't see that it would really correct this but you seemed to think it would help. Jean Jean, There are no air leaks as far as I'm aware although I'll check. I have not tried the single pulse. I don't really think it will make much difference. As Rod's scope has shown, the pulses are quite close. Rod, I'm not surprised at the high pulse width. Req-Fuel is 4.8 with the smaller injectors. VE in the table is close to 100%. Maybe the little extra is due to low voltage correction. Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
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8604 Posts Member #: 573 Formerly Axel Podland |
14th Mar, 2009 at 04:35:52pm
On 14th Mar, 2009 Rod S said:
I've noticed you have your pulses set to timing tables (which I expected) but trigger point, mid pulse...... What was your logic as you are spreading the timing both forwards and backwards. Not important at the moment, just makes it harder to figure out where the cam pulse is !!! I chose mid-pulse timing so that when injectors were changed for larger or smaller, it should not be necessary to adjust the timing table. That assumes that you can configure the timing to an optimum setting, which I have not been able to do so far. It is not that important to understand where the cam pulse is. My understanding is that the cam pulse just resets a flag in the code to tell the procesor which injector to fire. I was swinging my cam sensor around this afternoon to check that it was well away from the spark/injection timing. I now have it set so that it is mid way between the points at which the engine starts to run rough. Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
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5988 Posts Member #: 2024 Formally Retired Rural Suffolk |
14th Mar, 2009 at 04:43:26pm
The reason for my wanting to know where the cam pulse is (from the JimStim in this case) is because I want to be able to redraw the injector pulses on a graph of valve openning.
Schrödinger's cat - so which one am I ??? |
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8604 Posts Member #: 573 Formerly Axel Podland |
14th Mar, 2009 at 04:45:52pm
On 14th Mar, 2009 Rod S said:
Now 6000 RPM but remember my MAP sensor is at 1 bar (abs) rather than slightly below 
First thing I noticed, both injectors are above 5 mSecs And on the scope 
Now I always though that the pulse width given in MT was the effective pulse width plus the opening time. Clearly from the above, the pulse width shown in MT is the effective pulse width alone. So as with your own test Rod, the pulse widths are much higher. Can you check the voltage correction? Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
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1267 Posts Member #: 831 Post Whore Montreal, Canada |
14th Mar, 2009 at 04:54:00pm
What is reported in MT is the commanded pulse width, i.e., the duration of the electrical signal to the injector. So this includes the open time. If the scope is set at 2ms per division, it matches the MT displayed values.
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8604 Posts Member #: 573 Formerly Axel Podland |
14th Mar, 2009 at 04:57:40pm
On 14th Mar, 2009 Rod S said:
The reason for my wanting to know where the cam pulse is (from the JimStim in this case) is because I want to be able to redraw the injector pulses on a graph of valve openning. Where it actually occurs on the engine is irrelevant (as you say) so long as it's within Jean's parameters to make the reset occur correctly. But a good start would be if I could superimposed the inlet valve "pulses" on top of the scope photo. I think this will help us understand the mixture distribution if we can estimate things like transit time down the port. Does that make sense ??? I have calculated the transit time and plotted the injection pulses and valve opening on a piece of graph paper. BUT, if I set the injection timing to the theory then it runs poorly. There is far more to this than pure transit time. There are pulses that screw it all up. Plus when the first injefctor fires, the port is static. But you need to fire the second pulse just as the inlet valve opens on the inner cylinder just to get the fuel into the outer cylinder in time. I believe that this is why changing a setting for one affects the other. Up to 3500 rpm I can get the AFRs equal with an inection timing of 115 degrees before TDC for each pulse. Above 3500 rpm something is preventing me from getting more of the fuel into the outer cylinders and less into the inners. Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
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8604 Posts Member #: 573 Formerly Axel Podland |
14th Mar, 2009 at 04:59:22pm
On 14th Mar, 2009 jbelanger said:
What is reported in MT is the commanded pulse width, i.e., the duration of the electrical signal to the injector. So this includes the open time. If the scope is set at 2ms per division, it matches the MT displayed values. Jean Of course. Sorry, it's been another hard day. Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
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1267 Posts Member #: 831 Post Whore Montreal, Canada |
14th Mar, 2009 at 05:14:33pm
I would really spread the pulses apart. If you have similar pulse widths to what Rod is showing, there isn't enough time to close and reopen the injector and that means you're not in a linear section of the injector behaviour: you don't really know how much fuel you're injecting.
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5988 Posts Member #: 2024 Formally Retired Rural Suffolk |
14th Mar, 2009 at 05:19:07pm
On 14th Mar, 2009 Paul S said:
I have calculated the transit time and plotted the injection pulses and valve opening on a piece of graph paper. BUT, if I set the injection timing to the theory then it runs poorly. There is far more to this than pure transit time. There are pulses that screw it all up. Plus when the first injefctor fires, the port is static. But you need to fire the second pulse just as the inlet valve opens on the inner cylinder just to get the fuel into the outer cylinder in time. I believe that this is why changing a setting for one affects the other. Up to 3500 rpm I can get the AFRs equal with an inection timing of 115 degrees before TDC for each pulse. Above 3500 rpm something is preventing me from getting more of the fuel into the outer cylinders and less into the inners. Fair enough, it obviously isn't going to be straightforward, but I think plotting the actual pulses (at various RPMs) against actual valve timings, and even then hopefully superimposing AFRs from the widebands, will help progress. It should be a lot easier once my digital USB thingy arrives, in the meantime, what's your cam timing ??? I want to try and set some graphing up in excel. BTW, do you know what those two error messages were in your .msq file ??? Schrödinger's cat - so which one am I ??? |
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1267 Posts Member #: 831 Post Whore Montreal, Canada |
14th Mar, 2009 at 05:38:38pm
You should be able to get more details about the MT errors if you go in your project directory and look at audit.log.
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8604 Posts Member #: 573 Formerly Axel Podland |
14th Mar, 2009 at 06:45:35pm
On 14th Mar, 2009 Rod S said:
what's your cam timing ??? Inlet duration is 248 degrees, on a 12/56. On 14th Mar, 2009 Rod S said:
do you know what those two error messages were in your .msq file ??? I've never seen any errors and cannot find anything in audit.log. I think that the problem is your end. Search you computer for audit.log and open in Notepad. Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
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8604 Posts Member #: 573 Formerly Axel Podland |
14th Mar, 2009 at 07:01:16pm
On 14th Mar, 2009 jbelanger said:
If you have to, you can have widely different settings for injection timing at lower and higher RPM. You seem to have a good setup for RPM under 3500. So keep this but try moving the injection pulses apart higher up to see what that looks like. Jean Over the last three weekends I've so far use two full tanks of petrol, driving several hundred miles trying to find the optimum settings. A lot of this was in top gear at 4/4500rpm, the only way to get prolonged periods at WOT. Good job I have high gearing and a small engine. We have tried varying the VE tables and spreading the injection points apart as you suggest. The best settings that we have found so far are as follows: Use table previously generated by Autotune on the earlier code for VE Table 1. Reduce VE Table 1 by 20% for VE Table 2. Increase Req_Fuel by 10% to compensate. For WOT, 115 Degrees injection advance on both Injection Timing tables up to 3000 rpm. Above that reduce Injection Timing Table 1 to 50 Degrees at 6000 rpm. Maintain Injection Timing Table 2 at 115 Degrees. Injection Timing values reduced at lower MAP down to 80 Degrees at Idle. Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
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5988 Posts Member #: 2024 Formally Retired Rural Suffolk |
14th Mar, 2009 at 07:02:20pm
The audit log thing does seem to by my end...
Schrödinger's cat - so which one am I ??? |
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5988 Posts Member #: 2024 Formally Retired Rural Suffolk |
14th Mar, 2009 at 07:09:09pm
On 14th Mar, 2009 jbelanger said:
I would really spread the pulses apart. If you have similar pulse widths to what Rod is showing, there isn't enough time to close and reopen the injector and that means you're not in a linear section of the injector behaviour: you don't really know how much fuel you're injecting. If you have to, you can have widely different settings for injection timing at lower and higher RPM. You seem to have a good setup for RPM under 3500. So keep this but try moving the injection pulses apart higher up to see what that looks like. Jean I think this alludes to my first comment - the two pulses I see on the scope are just too close together. Now I've only looked on the scope at 6k RPM but I've seen your tables (I briefly looked whilst confirming I had the timebase trigger set the way I wanted) and although the two varied, perhaps worth trying some more as Jean suggests - esp. as your injector duty is over 25% at WOT full power. Sorry, I may not be thinking straight, but I want to get this graphed properly and need a clear head (ie, tomorrow). EDIT - I didn't see you had already replied to Jean, must have been while I was typing :) Edited by Rod S on 14th Mar, 2009. Schrödinger's cat - so which one am I ??? |
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8604 Posts Member #: 573 Formerly Axel Podland |
14th Mar, 2009 at 07:16:53pm
Rod, remember that what you scope reads is 1mS longer than the period the injector is open.
Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
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5988 Posts Member #: 2024 Formally Retired Rural Suffolk |
14th Mar, 2009 at 07:29:12pm
Right, not exactly at my best at the moment, but I don't think the pulses are overlapping, I just think they are too long, too close together, and the pair seems much greater than the valve opennings.
Schrödinger's cat - so which one am I ??? |
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1267 Posts Member #: 831 Post Whore Montreal, Canada |
14th Mar, 2009 at 07:31:21pm
Paul,
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1267 Posts Member #: 831 Post Whore Montreal, Canada |
14th Mar, 2009 at 07:33:11pm
On 14th Mar, 2009 Rod S said:
I'm going to try some lower RPMs in a moment as you say your AFRs were better then.... BUT.... were they WOT at lower RPMs as I can't simulate different MAPs at the moment. Can't you suck on the MAP nipple? :) :) |
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 6743 Posts Member #: 828 Post Whore uranus |
14th Mar, 2009 at 07:35:26pm
sounds like the higher fuel pressure may pay off then to shorten the pulse .. how high can it go ,,,70 psi ?what is the inj flow and pressure on the mpi mini? Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM |
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