Strange Idle Issue/Idle hunting with large injectors

Calibrations for S-Manager - Use all calibrations at your own risk (dyno tuning recommended)
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angrybaconman
Posts: 5
Joined: Mon Jul 31, 2023 10:14 am

Strange Idle Issue/Idle hunting with large injectors

Post by angrybaconman »

Yes I've read every single forum and post available online regarding idle hunting. I've smoke tested everything with all 3 sets of injectors I have.

TLDR. I have an idle hunting issue, but only with large injectors, if I throw my stock 240cc injectors back in and change the deadtimes back to stock it runs fine. I first had Hunter Tuned 1000CC injectors, and my tuner told me they were decapped and just hard to get to idle normally. So fine, whatever, I ordered FIC 1000CC injectors. Installed them, changed the deadtimes aaaaand exact same issue.

Car runs great while cold, but as it warms up the idle starts to slowly bounce around and then get worse. The only way to solve the hunting idle was to make the idle section a little richer than id like, and drop it down to like 10 degrees of timing. The rpm is steady now, but the AFRs still bounce from 12-15 at a solid steady rate. What's strange, is if I turn closed loop on it instantly solves everything. So it should just be a fueling issue right???? I have no idea, I've been chasing this issue for a month now.

Fuel pressure is set to 44PSI, with the car off. About 38 with the car running, vacuum line attached. 1997 Integra, entire car swapped to 1995 GSR OBD 1 harness with p75 ECU (don't ask, the guy before be was an idiot), B18b1, 9:23:1, BC springs and retainers, stock cams, stock intake, Go autoworks turbo kit, PTE5831, 3 inch exhaust, 4BAR map, DW200, AEM fuel pressure regulator. Heat range 7 plugs at .022.


Idle issue with rpm and ARFs all over the place. I drove around the block too
Datalog20.s3d
1997Integra1000cc 4bar EVO Basecal v1.8 (1).skl
After changes to idle timing, Rpm steady, but AFRs still consistently bounce up and down.
Datalog21.s3d
1997Integra 1000cc 4bar EVO Basecal v1.8 (2).skl

At this point I'm grasping at straws, I have researched and spent hours trying everything I can find online. Also hot starts in this car are rough for a solid 20-30 seconds. Haven't even tried to fix that yet.
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Spunkster
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Location: Hondata

Re: Strange Idle Issue/Idle hunting with large injectors

Post by Spunkster »

With the idle control valve unplugged, what RPM does it idle at?
angrybaconman
Posts: 5
Joined: Mon Jul 31, 2023 10:14 am

Re: Strange Idle Issue/Idle hunting with large injectors

Post by angrybaconman »

Spunkster wrote: Mon Mar 25, 2024 9:24 am With the idle control valve unplugged, what RPM does it idle at?
Around 600-700, rpm still bounces around and sometimes stalls, unless i make it run super rich. Again I've smoke tested the entire intake system 3 times, no vacuum leaks.
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Spunkster
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Location: Hondata

Re: Strange Idle Issue/Idle hunting with large injectors

Post by Spunkster »

It could be the dead times of the injectors
92EGinTN
Posts: 18
Joined: Thu May 18, 2023 9:03 am

Re: Strange Idle Issue/Idle hunting with large injectors

Post by 92EGinTN »

I had trouble with the huntertuned 1000's myself with getting them to idle anything above a 13.5afr. I played with the deadtimes some and have got them dialed fairly well. Post what dead times you're running with them. for 43.5psi FP I have been running (8v-2.33) (10v-1.86) (12v-1.46) (14v-1.12) (16v-0.85). I've tried many other combo's but these have worked the best for me.
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