Cam angle "Jitter"

K-Series Programmable ECU installation questions / support issues
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Slip_Angle
Posts: 78
Joined: Wed Apr 11, 2007 8:26 pm

Cam angle "Jitter"

Post by Slip_Angle »

02 Civic Si - PNF ECU
Kmanager 1.3.7.0
K24a2 swap, headers, exhaust, secondary o2 disabled, functioning cat...
K24a2 is stock (no vtc changes, no cams etc..)

Is it normal to have this sort of cam angle jitter as seen in my datalog? Cam is close to camcmd but it looks very wavy.
Attachments
TSX-Race-Header-Intake-2009-09-16.1.kal
(47.03 KiB) Downloaded 43 times
cam-jitter.kdl
(620.63 KiB) Downloaded 61 times

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Hondata
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Post by Hondata »

No, that is not normal. Try cleaning the VTC solenoid and VTC filter (near #1 intake runner) to see if it helps.
Hondata

Slip_Angle
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Joined: Wed Apr 11, 2007 8:26 pm

Post by Slip_Angle »

Hondata wrote:No, that is not normal. Try cleaning the VTC solenoid and VTC filter (near #1 intake runner) to see if it helps.
I'll check these on the weekend.

I posted this on another forum and someone pointed out that ignition was doing the same thing in my datalog. If you put ignition together with the cam angle in a graph template, it seems they follow a similar pattern.

Slip_Angle
Posts: 78
Joined: Wed Apr 11, 2007 8:26 pm

Post by Slip_Angle »

The VTC screen was dirty so I swapped it out. No change in the jitter. I then swapped out the VTC solenoid and the jitter was reduced by about 90-95%. I would have expected the problem to either go away completely or not at all..

One other thing I noticed is that camcmd doesn't follow what's in the table all the time. For example, I'll be in a 20 degree cam area for a few seconds and camcmd says 19. I think this is unrelated to the problem above but odd as well.

Any more suggestions?
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VTC-Swapped.kdl
(500.54 KiB) Downloaded 36 times

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Spunkster
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Post by Spunkster »

Cam position is interpolated from the different maps, so 19 when reading between the 10 and 20 table is normal.

Slip_Angle
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Post by Slip_Angle »

Hondata, does the datalog look OK/normal now? Still seems abit abnormal to me.. Please review and let me know. I also checked and cleaned the two ground connections.
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swapped-VTC-Solenoid.kdl
(1.65 MiB) Downloaded 40 times

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Hondata
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Post by Hondata »

Much better, but there are spikes every time you change gears. Run the car a little longer without uploading any calibrations, so that the ECU performs a longer learn cycle, and see if that helps.
Hondata

6spd_ek
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Post by 6spd_ek »

EDIT - I am going to try an rsx-s/ep3 si vtc solenoid as I am running an EP3 harness on a TSX motor with a TSX solenoid. the TSX solenoid is the same part # as the '06+ si but NOT the k20a2 & k20a3 vtc solenoids

(before edit) well I am still having major issues with vtc jitter even after cleaning the solenoid & screen.
Last edited by 6spd_ek on Thu Oct 29, 2009 8:45 pm, edited 1 time in total.

6spd_ek
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Post by 6spd_ek »

ok - problem solved! I decided to swap a used type R k20a "PNC" vtc solenoid into my k24a2 (w/ep3 harness) & the "jitter" is gone.

I am happy.

I have attached the datalogs (vtc set at 15 on full load). please forgive me for the partial tune you see. Should be street & dyno tuned week - I wanted to get this figured out 1st
Attachments
10.28kal.kal
calibration
(50.29 KiB) Downloaded 30 times
10.27.01 at 15.kdl
BEFORE - RBB vtc solenoid in a TSX motor with EP3 harness
(370.28 KiB) Downloaded 33 times
10.29.01.kdl
AFTER - PNC vtc solenoid in a TSX motor with EP3 harness
(1.52 MiB) Downloaded 32 times

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