Slight light throttle drivability problem after tune?

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Slight light throttle drivability problem after tune?

h10ndr Wed Aug 27, 2008 1:35 pm

Hi

After recently getting my H22A motor tuned on a dyno dynamics with a OBD-1 P72 ecu + Neptune RTP I've had a week or two to drive it around. Although it drives well enough, I've noticed a few small problems which I thought someone on here might be able to help with.

Car starts fine from cold and idles fine, even when warm. However, occasionally after its been driven for 10mins the car decides it doesn't want to idle anymore. It stumbles around the 590-650rpm mark when I let of the throttle or pull up at a junction. It very nearly stalls, but after 2-3 secs of this the idle resumes ok. What can cause this?

Also the othe problem I have noticed is that when I let off the throttle in gear after accelerating, the car pushes on for a fraction, like there is a lag between throttle response? What could cause this? Is it something to do with the fuel cut? or because I have the fuel pump "always on"?

And finally, when running downhill with a light engine brake effect in 4th gear as the revs arrive at about 2000rpm, there is a low resonance popping from the exhaust...
Is this caused by ignition in the low load columns?

Any help appreciated?

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HRTuning Wed Aug 27, 2008 4:28 pm

You can try adjusting the IACV.

Fuel cut delay.

That will depend on your setup, including your exhaust system.

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h10ndr Sun Sep 21, 2008 9:40 am

I have adjusted the fuel cut delay slider from showing just over half way to less than a quarter, and this seems to have helped alot. Very Happy

I have also adjusted the IACV to 60% and changed the LOW LOAD FUEL trims in the IAT Corrections to 0 above 70* Celsius. This is because my poor idle seems to happen when the car is warmed up and in warmer weather.

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HRTuning Sun Sep 21, 2008 3:27 pm

At least it's better. Smile

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APTuning Tue Nov 09, 2010 8:54 am

Increasing the idle speed can help prevent this too.

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98vtec Thu Nov 11, 2010 3:20 pm

h10ndr wrote:I have adjusted the fuel cut delay slider from showing just over half way to less than a quarter, and this seems to have helped alot. Very Happy

I have also adjusted the IACV to 60% and changed the LOW LOAD FUEL trims in the IAT Corrections to 0 above 70* Celsius. This is because my poor idle seems to happen when the car is warmed up and in warmer weather.


make use of the live logging and you can pin point what table is effecting this event the most. May take a few times changing the logging displays but im sure you will find it.

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