lean tip-in

FlashPro questions & answers specific to the 2006-2009 (US, UK, Asia) S2000
shind3
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lean tip-in

Post by shind3 » Tue Aug 26, 2014 6:54 pm

I'm getting a sharp lean spike just after tip-in. It is very noticeable. I couldn't find a tip-in enrichment to adjust. How do I fix this?

Thanks.
Attachments
Shek 70mm TP, 08.fpcal
(8.4 KiB) Downloaded 138 times
tip in lean 4.fpdl
(10.03 KiB) Downloaded 149 times
tip in lean 3.fpdl
(12.15 KiB) Downloaded 135 times
tip in lean 2.fpdl
(10.78 KiB) Downloaded 131 times
tip in lean.fpdl
(11.92 KiB) Downloaded 142 times

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Hondata
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Re: lean tip-in

Post by Hondata » Tue Aug 26, 2014 7:01 pm

I think you're chasing symptoms here, and changing the tip in fuel will not help, as the lean spot duration looks a lot longer than what tip in covers.
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shind3
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Location: Pittsburgh, PA

Re: lean tip-in

Post by shind3 » Tue Aug 26, 2014 8:51 pm

I see. What do you recommend? Only modification is a 70mm TP. I've attached my calibration.

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Hondata
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Re: lean tip-in

Post by Hondata » Wed Aug 27, 2014 8:37 am

Work through and eliminate all the causes of the problems you're seeing until the stock operation of the engine is good. eg fuel pump, pressure regulator, injectors, cam timing, sensors, throttle body, exhaust restriction, spark plugs, leak down etc
Hondata

shind3
Posts: 109
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Location: Pittsburgh, PA

Re: lean tip-in

Post by shind3 » Wed Aug 27, 2014 9:17 am

Oh, so you're saying this is not a software issue.

I was hoping analysis of datalogs would help steer me towards what to check. But you basically just threw the book at me and said it could be any one of those things. Cam timing? Really?

Can any of those causes be eliminated by examination of the datalogs? Or other datalogs I can gather in different scenarios?

pepperdanky
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Re: lean tip-in

Post by pepperdanky » Wed Aug 27, 2014 1:37 pm

Your ignition is dropping down to 0* when you increase throttle for some reason. Is the ECU throwing any codes?

shind3
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Location: Pittsburgh, PA

Re: lean tip-in

Post by shind3 » Wed Aug 27, 2014 6:57 pm

No codes.

shind3
Posts: 109
Joined: Mon Jun 30, 2014 8:02 am
Location: Pittsburgh, PA

Re: lean tip-in

Post by shind3 » Wed Aug 27, 2014 10:00 pm

Looking at the timestamps, the lean dip lasts for about 300 to 400ms. Isn't that well within reason of tip-in enrichment or X Tau (wall wetting) settings?

So Hondata, how does Honda do tip-in enrichment? Most ECUs add extra fuel based on rate of TPS change or MAP change.
Attachments
datalog0012.fpdl
(7.63 KiB) Downloaded 131 times
datalog0011.fpdl
(7.14 KiB) Downloaded 124 times

pepperdanky
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Re: lean tip-in

Post by pepperdanky » Thu Aug 28, 2014 5:00 am

From what the ignition is doing, that lean spike is likely unburnt fuel in your exhaust.

You checked the DTCs in FlashPro? It might show something without triggering the MIL.

shind3
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Location: Pittsburgh, PA

Re: lean tip-in

Post by shind3 » Thu Aug 28, 2014 7:28 am

Yeah, the oxygen sensor would show a misfire as a lean spike but check the last 2 datalogs I posted at further up in the RPM range around 2500-3000RPM. There the ignition timing doesn't drop to 0 but gets close to 10 or so. Still the same thing with the AFR. I guess it's still a lot lower than commanded.

I'll check for pending DTCs as requested.

shind3
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Location: Pittsburgh, PA

Re: lean tip-in

Post by shind3 » Wed Sep 03, 2014 8:33 pm

I don't see any pending DTCs.

The problem only shows up when MAP increases quickly, like 10kPa in 100ms. Otherwise the car runs well everywhere else. Long term fuel trims are less than 2-3%, powerband is smooth with no knock counts etc.

And the lean spike only lasts about 300ms at 3000RPM. This again points to a tip-in enrichment issue.
Image

Hondata, how does Honda calculate tip-in (accel enrichment)? I know the engine must inject extra fuel during a high rate of manifold pressure increase as the fuel vapors condense on the walls. I just want a way to tune it.

Thanks.

shind3
Posts: 109
Joined: Mon Jun 30, 2014 8:02 am
Location: Pittsburgh, PA

Re: lean tip-in

Post by shind3 » Fri Sep 19, 2014 6:28 pm

Ran two bottles of Chevron Techron thru 24 gallons of fuel. No change.

Installed a new Fuel Pulsation Damper even though the old one seemed to move the set screw up and down. Thought maybe the spring got weak over the course of 90K miles and maybe wasn't reacting as intended. No change in datalogs.

I also checked cam timing. Looks spot on. Again, no change.
Image
Image

shind3
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Re: lean tip-in

Post by shind3 » Thu Jun 11, 2015 8:48 pm

Bump. Lots of people reporting the same issue on S2ki.com. Can we PLEASE have the ability to tune Accel Enrichment?

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Re: lean tip-in

Post by Hondata » Sun Jun 14, 2015 4:17 pm

Then they need to post calibrations and datalogs here.
If you are using a large throttle body, have you adjusted the flow vs angle table?
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shind3
Posts: 109
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Location: Pittsburgh, PA

Re: lean tip-in

Post by shind3 » Wed Jun 17, 2015 6:33 am

Stock throttle body.

Also, I have access to HDS and ran the ETCS tests where it runs the throttle body through some correlation tests. Passed.

Can I datalog an ECU that is not 'married' to the FlashPro? If so, I can try to find some 2006+ S2000s locally and datalog them using mine.

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