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Nissan ECU Tuning
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Vetal
Joined: 08 Feb 2006
Posts: 120
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 Posted: Wed Mar 12, 2008 8:06 am Post subject: |
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| raddy wrote: | that sound strange, as with flap more closed (less airflow) AFM senses it correctly, but with more airflow it doesnt detect it correctly? Also, Im able to rev engine at neutral without any problem that can by caused by this type of AFM malfunction,even in very rapid full throttle....
I have idea that it can be caused as ECU try to maintain idle rpm at given value, but becouse throttle adjusting it cannot regulate idle with AAC valve (even with fully closed AAC are idle still high), so it try to lean out mixture to decrease rpm? I can see connection between this theory and fact, that AFR was oscillating up and down, it wasnt just lean. that just my idea though... |
yes, my theory was that AFM doesn't sense small changes in airflow caused by changing throttle angle. I'm not saying it's malfunctioning, more probably dirty AFM.
But actually if AFR jumps, then I don't know... |
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Vetal
Joined: 08 Feb 2006
Posts: 120
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| Posted: Wed Mar 12, 2008 8:07 am Post subject: |
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| Actually my friend with Z32 also has issues with idle when it's warm - it changed between 13 and 19. Don't know why really |
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cb_drift
Joined: 04 May 2004
Posts: 468
Location: New Zealand
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| Posted: Wed Mar 12, 2008 10:36 am Post subject: |
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weird - ive seen z32afm with 800cc injectors and a t88 turbo on a ca18det idling perfectly at 14.7 stable and making - errr - lots of power (crap drivers car or drift car - GREAT dyno queen or drag car tho)
I think liveedit had a "rb20det for ca18" afm in it that worked well...
if it doesnt have the vq map - sing out and i'll upload it (the vq map) |
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raddy
Joined: 29 Nov 2005
Posts: 95
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| Posted: Wed Mar 12, 2008 2:11 pm Post subject: |
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| Im used liveedit, RB20DET AFM for CA18DET, doesnt touch TTPMIN, as this is little bit complicated at CA18det case, inj. latency is 55h, injectors size is 444ccm. I will test it again now with adjusted throttle to get more results, but for now it idles at about 15:1, without changing it like before. Also, I think if AFM will be dirty (which doesnt look like, but I will check it again) it should produce some shattering while revving engine at neutral (if AFM doesnt sense increased airflow after opening throttle), but it is smooth both with small and slow throttle opening and fast and full throttle... |
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cb_drift
Joined: 04 May 2004
Posts: 468
Location: New Zealand
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| Posted: Wed Mar 12, 2008 7:20 pm Post subject: |
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Im used liveedit, RB20DET AFM for CA18DET, doesnt touch TTPMIN, as this is little bit complicated at CA18det case, inj. latency is 55h, injectors size is 444ccm. I will test it again now with adjusted throttle to get more results, but for now it idles at about 15:1, without changing it like before. Also, I think if AFM will be dirty (which doesnt look like, but I will check it again) it should produce some shattering while revving engine at neutral (if AFM doesnt sense increased airflow after opening throttle), but it is smooth both with small and slow throttle opening and fast and full throttle...
Ahhh - increase latency to make idle richer 
dont trust live edit's recommendation on the null value to put in ...
very very very very basicly - use the null value to tweak the afr at idle (when map is set to 0 and o2 is off) and use the k to set the full load fueling
give that a go and see what happens...
15:1 isnt a bad idle tho...
*shrug* whatever "works" and gives the best results |
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raddy
Joined: 29 Nov 2005
Posts: 95
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| Posted: Thu Mar 13, 2008 7:57 am Post subject: |
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I see what you mean, but Im still under impression that my original problem (jumping AFR at idle from 14.7 to 19 and back) is reason of something more mechanical (boost leak, throttle setting etc) more than inejctor latency.
Originally I used latency 37, than 47, now 55, but nothing of this changes doesnt change AFR problem....
Anyway, what null value you recommed to use, should I really go higher? (there are GTIR 444cc injectors).
Thanks for opinions gentlemans, will test it further in few days.... |
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