Hi Morris - the injectors from the honda are high impedence, so I hope I don't need to play around with the PWM - I've got enough settings to confuse me already...
I spent more than a few hours today (8C and sunny, what a nice day to be out) and made a fair bit of progress. I never could eliminate the dive into lean territory as I would crack the throttle to move off from a stop. So I switched to alpha-n, which made a night and day difference. I guess it's because my TB is very large, I was getting quite a jump in the MAP from just cracking the throttle. I'm still getting a dip in the O2 meter, but at least I don't need to feather the throttle or bring up the RPMs to move away anymore.
What are downsides to alpha-n? One I could think of is that alpha-n doesn't adjust to a dirty airfilter as easily as speed/density, right?
any tips to tune out an off idle stumble?
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Read the manual to see if your question is answered there before posting. If you have questions about MS1/Extra or MS2/Extra or other non-B&G code configuration or tuning, please post them at http://www.msextra.com The full forum rules are here: Forum Rules, be sure to read them all regularly.
Forum rules
Read the manual to see if your question is answered there before posting. If you have questions about MS1/Extra or MS2/Extra or other non-B&G code configuration or tuning, please post them at http://www.msextra.com The full forum rules are here: Forum Rules, be sure to read them all regularly.
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efahl
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Mike,mikesb wrote:What are downsides to alpha-n? One I could think of is that alpha-n doesn't adjust to a dirty airfilter as easily as speed/density, right?
A-N can't compensate for barometric changes on the intake side like SD and MAF do naturally, so you need to re-tune for weather conditions just like you'd re-jet a carb for baro changes.
Eric
Thanks Eric, good points. I found the writeup for megasquirt on alpha-N, and it convinced me to try to go back to speed density.
But I just can't seem to get it sorted. If I set my VE values to avoid the hesitation on opening the throttle, I can't drive away from a stop - the engine jumps right into that same bin - very rich - and can't make any power. But if I put the bins to what I need for power there, I get a spit back through the intake when the throttle first opens.
Here's a log showing the problem. As you can see, it jumps to lean even in the middle of the accelerator pump. It's fine when the RPMs are higher, I can blip the throttle fine. But off idle, it struggles.
Any ideas?
When I use alpha-n I can just about eliminate the hesitation.
But I just can't seem to get it sorted. If I set my VE values to avoid the hesitation on opening the throttle, I can't drive away from a stop - the engine jumps right into that same bin - very rich - and can't make any power. But if I put the bins to what I need for power there, I get a spit back through the intake when the throttle first opens.
Here's a log showing the problem. As you can see, it jumps to lean even in the middle of the accelerator pump. It's fine when the RPMs are higher, I can blip the throttle fine. But off idle, it struggles.
Any ideas?
When I use alpha-n I can just about eliminate the hesitation.
No takers then 
. I'm at a loss to sort this, played with it quite a bit over the weekend (and I'm hoping to again this weekend). The obvious solution would be to increase the accelerator injection, but it's already too rich and stumbles on acceleration from high gear.
I've noticed that it's worst when I blip the throttle, say for a heel and toe coming to a corner. The accelerator pump is cut off as soon as decelleration is detected and I can get a pretty good (sounding) pop out of the intake and a stumble when I get into gear and try to accelerate out of the corner.
My next plan is to try the alternatives of less accelerator enrichment for a longer duration, or more for a shorter duration. I think the latter is the right way to go, but I'm already down to 0.5s - what's a reasonable number?
. I'm at a loss to sort this, played with it quite a bit over the weekend (and I'm hoping to again this weekend). The obvious solution would be to increase the accelerator injection, but it's already too rich and stumbles on acceleration from high gear.I've noticed that it's worst when I blip the throttle, say for a heel and toe coming to a corner. The accelerator pump is cut off as soon as decelleration is detected and I can get a pretty good (sounding) pop out of the intake and a stumble when I get into gear and try to accelerate out of the corner.
My next plan is to try the alternatives of less accelerator enrichment for a longer duration, or more for a shorter duration. I think the latter is the right way to go, but I'm already down to 0.5s - what's a reasonable number?
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mops
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hm.... cant help you much, as i dont see afr feedback on the log. I presume you dont have oxygen sensor.
accel enrich should be more like 0.2 to 0.3. On large TB it's normally large by short. I had problems tuning my accelenrich, and thats how i done it.
I zeroed all the pulse boxes (effectively no enrichment) (on the map side)
start with small throttle openings. put 1 in all 4 pulse boxes on the map side). rev it out few times. try reving from idle aswell from higher rpm's.
notice chahge (if any).
I have large TB and in my accel enrichment I have values like 1.5 and 1.8 ms, not like suggested default 5 and 9....
secondly... accel enrich will not make it up for bad ve table. if you gont have that right then that what you need to work on first. if you are controlling timing, that might be an issue aswell - I suggest set it to something like 10* everywhere for a start....
I have LC-1 wideband so I have feedback what happening, but I would have no clue how would i go about tuning without any oxy sensor.
i suppose with narrowband you can set your afr targets to 14.7 and tunr some part that way...
accel enrich should be more like 0.2 to 0.3. On large TB it's normally large by short. I had problems tuning my accelenrich, and thats how i done it.
I zeroed all the pulse boxes (effectively no enrichment) (on the map side)
start with small throttle openings. put 1 in all 4 pulse boxes on the map side). rev it out few times. try reving from idle aswell from higher rpm's.
notice chahge (if any).
I have large TB and in my accel enrichment I have values like 1.5 and 1.8 ms, not like suggested default 5 and 9....
secondly... accel enrich will not make it up for bad ve table. if you gont have that right then that what you need to work on first. if you are controlling timing, that might be an issue aswell - I suggest set it to something like 10* everywhere for a start....
I have LC-1 wideband so I have feedback what happening, but I would have no clue how would i go about tuning without any oxy sensor.
i suppose with narrowband you can set your afr targets to 14.7 and tunr some part that way...
BMW, 1985, E30, 325i, 2-door, 5spd , 127k miles, short shift, MSII, V3/code 2.684/60-2 wheel/MT 2.25, LC-1 wbO2, ignitor module mod driving msd coil/, 3 pin Bosch PWC IAC mod
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Keithg
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well, I fought this for a while, then enrichened the high map, low rpm bins (<1200 rpm, 50-80 kpa) to be a bit richer and was able to tune a decent AE. I then went to a RPM based AE and it got even better (msns-e). My idle VE is 48-50 at 900 rpm and 38 kpa. My AE is (was) 0.2 or 0.3s. I am now at 0.8s, but RPM based AE tapers this to 0, so that is not a comparison.
How is your TPS signal? Have you tried map based AE? A dirty signal from TPS could cause erroneous accel. Map based is what I use and it is set at 60 kpa/sec.
HTH
KeithG
How is your TPS signal? Have you tried map based AE? A dirty signal from TPS could cause erroneous accel. Map based is what I use and it is set at 60 kpa/sec.
HTH
KeithG
Thanks guys, good tips here. Shorter and richer for the AE is my next attempt then.
There should be , but I really should have mentioned I'm using the TE wblin, so AFR = O2*2 + 9.
Interesting point Arnold - I'm not using the vacuum advance right now because it was designed to be taken from the venturi, pure manifold vacuum is a bit much. But I can hook it up to check whether what I'm seeing is a misfire that looks way too lean to the O2 sensor, right?
TPS is really clean, it's from a bike and is rock steady.
Failing progress there, I'll switch to the msns-e. RPM dependent AE sounds just the ticket (ignoring that it's more things for me to fiddle with and get wrong...).
Next time I'll post a picture of the log viewer, that's gotta be easier than downloading the log itself.
There should be , but I really should have mentioned I'm using the TE wblin, so AFR = O2*2 + 9.
Interesting point Arnold - I'm not using the vacuum advance right now because it was designed to be taken from the venturi, pure manifold vacuum is a bit much. But I can hook it up to check whether what I'm seeing is a misfire that looks way too lean to the O2 sensor, right?
TPS is really clean, it's from a bike and is rock steady.
Failing progress there, I'll switch to the msns-e. RPM dependent AE sounds just the ticket (ignoring that it's more things for me to fiddle with and get wrong...).
Next time I'll post a picture of the log viewer, that's gotta be easier than downloading the log itself.
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mops
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ok, ok, i think I get it now....
looks like you accel enrich is ok, but your VE at certain points is stuffed.
AFAIK accelenrich should cover areas where your map/throttle is incerasing (which are really short periods of time). Good indication of bad AE is to examine the logs in the points you are incerasing throttle. with bad AE (too much or not enough), as map inserases rpm's are dropping... then as map stabilizes rpm start to incerase.
on your log, I see that as your map incerases quickly (for about 0.2-0.3 seconds), rpm stay the same (indicating AE is not bad, but not perfect), then map stabilizes and rpm incerase (thats where you are lean). I'd incerase appropriate rpm/map bins but, say 10% and run another datalog and see "huh" is goinng on. I can't see exacly from this graph, but 1500rpm/90 kpa should be alot richer up to 1800rpm/70 kpa richer too, and generally enrich and smooth out that area and make another datalog, see what happens....
as you release throttle afr's lean out, which is good.
I'm not an expert, I'd get a second opinion if I was you.
looks like you accel enrich is ok, but your VE at certain points is stuffed.
AFAIK accelenrich should cover areas where your map/throttle is incerasing (which are really short periods of time). Good indication of bad AE is to examine the logs in the points you are incerasing throttle. with bad AE (too much or not enough), as map inserases rpm's are dropping... then as map stabilizes rpm start to incerase.
on your log, I see that as your map incerases quickly (for about 0.2-0.3 seconds), rpm stay the same (indicating AE is not bad, but not perfect), then map stabilizes and rpm incerase (thats where you are lean). I'd incerase appropriate rpm/map bins but, say 10% and run another datalog and see "huh" is goinng on. I can't see exacly from this graph, but 1500rpm/90 kpa should be alot richer up to 1800rpm/70 kpa richer too, and generally enrich and smooth out that area and make another datalog, see what happens....
as you release throttle afr's lean out, which is good.
I'm not an expert, I'd get a second opinion if I was you.
BMW, 1985, E30, 325i, 2-door, 5spd , 127k miles, short shift, MSII, V3/code 2.684/60-2 wheel/MT 2.25, LC-1 wbO2, ignitor module mod driving msd coil/, 3 pin Bosch PWC IAC mod