rich idle

Discussions concerning the M7790 cpu

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thesandman6
 

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Joined: Wed Jul 22, 2009 2:39 pm

rich idle

Post by thesandman6 »

I'm having trouble leaning out my idle, my set up is ka24det, 750cc rc injectors, and a blowthrough n62. I set both my fuel maps to 0 raw and tuned off o2 feedback, then tuned my k for cruise and its good, 28500k. Now whenever I idle my afrs will drop to around 11. The latency for my injectors is listed at 630us, but the only i can start to lean out my idle is to drop the latency to around 350us which makes it closer to 13.5. When i go below 330us my motor just completely leans out and dies. I've also tried adjusting my ttp mins to .6ms with no changes. when i adjust my ttp max down i can get it to idle leaner but the engine dies. My fuel pressure is correct, my injectors are not leaking and ive tried to reposition the mafs at different angles but it still idles rich.
Matt
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Post by Matt »

can you get a log of the TP and injection time vs AFR with the low ttp min. See what pulsewdith you are getting to your injectors with the current tune (if you can put that up also)
Bernardd
 

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Post by Bernardd »

have you tried adjusting the vq map in the idle region? blowthru causes issue at idle in my experience.
thesandman6
 

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Joined: Wed Jul 22, 2009 2:39 pm

Post by thesandman6 »

ll try to get a log of the afr and injector time tomorrow if i can find some time. i had the idea to try to tweak the vq but haven't had the time to mess with it.
eduardo
 

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Post by eduardo »

thesandman6 wrote:ll try to get a log of the afr and injector time tomorrow if i can find some time. i had the idea to try to tweak the vq but haven't had the time to mess with it.
I have the same problem with this board 3 and nissan 300zx 16bit ecu, no matter what I do, I can't get it to idle leaner, it is always too rich with my bigger 740cc injectors
thesandman6
 

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Joined: Wed Jul 22, 2009 2:39 pm

Post by thesandman6 »

Just got my laptop fixed today and was checking everything out on my car again/. I noticed that my 4 month old tps doesn't change voltage till my rpm are over 1500, loosened it up and tried re adjusting and it has slop. I'm going to try throwing on a friend's oem one tomorrow and see how it goes. Hopefully this will fix my problem
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