lean condition on restart

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Spawne32
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Post by Spawne32 »

ive accepted that, whats bothering me is these weird fuckin afr's that make no sense, if the car got richer as it got hotter, i would understand it, air density lessens the hotter it gets sitting at idle, you need less fuel, i could just program that in the ECT and IAT tables, but the thing is, its getting leaner the more it heatsoaks, i cant figure out if its just the wideband overheating or if its an actual reading.

Almighty-Si
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Post by Almighty-Si »

Do you have any other logs? Preferably something you were driving around on.

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JaredKaragen
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Post by JaredKaragen »

Spawne32 wrote:ive accepted that, whats bothering me is these weird f*** afr's that make no sense, if the car got richer as it got hotter, i would understand it, air density lessens the hotter it gets sitting at idle, you need less fuel, i could just program that in the ECT and IAT tables, but the thing is, its getting leaner the more it heatsoaks, i cant figure out if its just the wideband overheating or if its an actual reading.
boil your ect and record ohms at temps, compare with scale... same with iat... maybe one is putting under-sized high temp values
95 Sol Si : D16z6 : TD04H-13C 74 Civic 1200 : 100% Stock

Spawne32
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Post by Spawne32 »

good news today, replaced the ICM with a wells/airtex icm just now, car fired right up, so im very happy with that now. Didnt realize these ICM's have heatsinks on them, basically like computer parts and such. The old ICM had barely any thermal paste from the heatsink to the backplate, so i whipped out some of my expensive computer building thermal paste, and put a nice thick ass coating of arctic silver ceramique (not electrically conductive) all over the new one.

Spawne32
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Post by Spawne32 »

ill get my datalogs for you guys if i still have them, if not ill record new ones when the problem occurs

elevation
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Post by elevation »

on warm start up the ecu doesnt check the coolant temp info for a bit so it reads the hotter temp for awhile, makes a lean condition. I watched this happen on my engine simulator.
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Spawne32
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Post by Spawne32 »

i dont even know what the fuck is going on anymore, its lean on a hot restart, and its rich in all the other places as it gets hotter, the new ICM made the car feel more consistent with timing, but as far as the AFR, its all over the place. It seems to be getting richer by gear, which ive never noticed before, so im not quite sure if that is normal or what working with an auto.

Natural Aspirations
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Post by Natural Aspirations »

now your crying in your Cheerios? buck up little guy

Spawne32
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Post by Spawne32 »

i dont have any cheerios here, just lucky charms and cinnamon life, side note though, i mayyyy have figured out the issue here with the lean restart. Ive always had my FPR hooked up to the vac side of the blower, not normally an issue, but, at idle the IACV is constantly making adjustments, one thing i noticed is that regardless of what the MAP sensor is reading, my fuel pressure is changing. I set my fuel pressure to 43.5psi at idle on a cold start, 800rpms. When i restart the car hot, im getting about 39psi, and it slowly starts to climb. I think that the vac line being before the blower the FPR is much more susceptible to the conditions of the IACV, throwing the idle fuel pressure out of wack. So what i have to do, i have to find out what size that one plug is on the intake manifold and get a hose barb to fit it, move the FPR to the intake manifold, and see how it reacts. Its gona throw my boost maps all out of wack but it should theoretically be more stable.

Spawne32
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Post by Spawne32 »

well switching the FPR and bypass valve around didnt work at all, went into the parts store to get some more vacuum fittings and such, came out, and car idled at 16.5:1 after starting it back up, i was in the store for a little over 5 minutes.

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TopMountGSR
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Post by TopMountGSR »

Also, we don't have fuel temp corrections, this plays a big part in the hot start lean conditions. You just have to ignore this specific issue. On your heat soak issue, A lot of the cars I tune, in the light load section of the iat comp tables, I add fuel as the temp increases past 100 degrees to aid this leaning out symptom seen during heat soak. This can be seen while idling in traffic so to speak. It seems ass backwards, but it works and keeps the afrs stable while it heat soaks at idle. Hope this helps, Dk
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