strange ve fuel table
#1
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strange ve fuel table
I'm doing my best at making my car run better with megasquirt and i'm noticing my ve fuel table looks reversed from any other one i've seen. Higher values in low kpa/rpm and lower values in high kpa/rpm. Seems to be the reverse of what i'd expect. These values are what autotune is deciding and car run reasonably well. Any idea of what would cause this?
Only real issue is my car will stall if I let the rpms fall to fast. I believe it is an over run fuel cut issue, so i'm playing with that a little.
Only real issue is my car will stall if I let the rpms fall to fast. I believe it is an over run fuel cut issue, so i'm playing with that a little.
#2
The low RPM high kpa cells (900 rpm 85 kpa in your picture for example) are most likely due to a poorly setup accel enrichment. For example, when you stamp on the throttle AFR's go lean for a moment then recover. During that lean event, the auto tune thinks you need alot more fuel in those cells when you only need proper acceleration enrichment to help compensate for that amount of TPSdot/MAPdot.
#3
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I'm doing my best at making my car run better with megasquirt and i'm noticing my ve fuel table looks reversed from any other one i've seen. Higher values in low kpa/rpm and lower values in high kpa/rpm. Seems to be the reverse of what i'd expect. These values are what autotune is deciding and car run reasonably well. Any idea of what would cause this?
Only real issue is my car will stall if I let the rpms fall to fast. I believe it is an over run fuel cut issue, so i'm playing with that a little.
Only real issue is my car will stall if I let the rpms fall to fast. I believe it is an over run fuel cut issue, so i'm playing with that a little.
my idle cells are in the 60's and boost in the 120-150's. and climbing with more boost/load. not flat or dropping like you have.
hows the AFR on the gauge? 11-12 in boost? 14.7 at cruise?
#4
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So you recommend having accel enrichment turned on when using autotune? How would this fix the idle cells which are also just as high
afr gauge reads exactly how you'd want it to. It follows my afr table perfectly.
afr gauge reads exactly how you'd want it to. It follows my afr table perfectly.
#6
I understand AE is not the only thing at play here. I've read through the similar recent threads and it surpasses what little knowledge I have with MS. I'm paying attention though so that I can maybe offer help to the next guy when no one else bites.
I was only commenting on one specific area of his map. low rpm high load. That area looks just like how mine did before I dialed in my enrichments. Hence my suggestion.
I was only commenting on one specific area of his map. low rpm high load. That area looks just like how mine did before I dialed in my enrichments. Hence my suggestion.
#9
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They were not crazy off, but getting them correct is pretty important. I learned that lesson years ago when my alternator went out and I drove briefly on ~12 volts. Hooooly **** did it run bad.
#11
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Is this MS2 or MS3? The DT and voltage slope posted above do not match IDs published data at 3 bar. Where did these numbers come from?
ID1000
ID1000
my mistake, didn't catch the 60psi point. Sorry!
#12
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I'm using a DIYPNP. I update the dead times and it changed a little. Car seems to run better. But req fuel still kinda funky looking. Any chance all this is caused my timing map? Does it look reasonable?
#13
I see this is a 2000 miata, so it might not be the same, but does it feel super sluggish? I had an issue like this on my 2003 NB2 due to my VTCS valve not opening, (even though the base map was set to have it open) so the car was running essentially with 10% of the expected air so autotune dialed back a TON of fuel to compensate when it was higher up the rev range/ kpa. Your issue looks similar to what I was battling. IIRC 99-2000 NB's have a VICS plenum and not VTCS so it wouldn't be as severe (or maybe not cause this kind of issue at all) I'm leaning toward this not being your issue, but it's worth looking into.
#14
What does it involve then? I'm having a similar issue but just not as severe where the fuel map is generally all in the 80s-100's. The car does not like lower numbers in the cruise cells and leans out. I've tried starting with different ve in cruise thinking it could be a rich misfire but I always end up having to put larger numbers. What I took out of this thread I'd that it's a deadtime issue? Yes no?
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