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Old 12-16-2005, 02:26 PM   #26
bboy
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I just happened across some stuff on the Hydra Forum on Throttle Pump and dEnrich that indicated their may be a "decay" associated with both--which does not make sense.

Do you see any difference in AFR depending on when you jump on the gas and does it correlated with misfire?
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Old 12-16-2005, 03:18 PM   #27
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Throttle pump definitely decays over time. It has to otherwise every time there was a sudden change in TPS it would run rich all the way to redline. The only reason for throttle pump is to prevent leaning out due to sudden changes in MAP that are not quickly picked up by the ecu. Once the ecu catches up there is no need for the extra enrichment.

The strategy used for tuning "throttle pump" varies with tuners. Some use it to just maintain the same AFR during these sudden changes while others use it to actually richen the AFR to prevent shift knock so they can get away with a little more ignition timing. The “TPS Sensitivity” effects when “Throttle Pump” is activated so the way I set it light throttle application do not set off “Throttle Pump.”

"Dynamic Enrichment and Enleanment" dictate how fast the ecu reacts to positive or negative changes to fuel based on RPM but its complex. I have tuned this through trial and error and best overall drivability. Changing this moderately has immediate and noticeable effects.

I don’t think any of this has to do with his misfires based on the post’s initial description of the problem. It’s a known problem that I have addressed with new dwell settings.

Thanks,
Phil
www.elementtuning.com

Last edited by Element Tuning; 12-17-2005 at 06:18 AM.
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Old 12-16-2005, 03:41 PM   #28
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OK, I'll shut up.
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Old 12-16-2005, 04:16 PM   #29
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Old 12-16-2005, 04:25 PM   #30
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Quote:
Originally Posted by bboy
OK, I'll shut up.
My post was to get ideas. You gave yours based on success you had, and I appreciate it. I don't rule anything out until the problem is solved.
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Old 12-16-2005, 11:53 PM   #31
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I am 90% sure the problem is gone.
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Old 12-17-2005, 06:57 AM   #32
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... and you did what?

changed the dwell?
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Old 01-11-2006, 05:25 PM   #33
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Changed the dwell.

Phil: It's not gone
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Old 01-11-2006, 06:55 PM   #34
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You had mentioned new plugs cure the problem temporarily so it's possible you have a coil pack(s) starting to go bad. This is pretty common on these cars and if you haven't had to replace them yet consider yourself lucky. The newer coil packs appear to be holding up very well on our Time Attack WRX.

Also I had mentioned that running leaner and adding timing were strategies for reducing misfires. I would try to get away with a couple more degrees of timing in the misfire area in particular and note the change. Hopefully you can get away with this using those colder plugs otherwise try the hotter plugs again.

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Old 01-11-2006, 07:28 PM   #35
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I will have to examine the coil packs then, as 20deg @ 5700RPM does not make it stop, nor does my current 15deg @ 5700RPM per our previous email conversation about my timing where it was recommended I pull 2 degrees from 15psi upward throughout my midrange to redline. AFRs are 11 - 11.4 to 1.
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Old 01-12-2006, 08:28 AM   #36
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i think it's that leftover bolt from the shortblock swap.

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Old 01-12-2006, 10:02 AM   #37
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Quote:
Originally Posted by jblaine
I will have to examine the coil packs then, as 20deg @ 5700RPM does not make it stop, nor does my current 15deg @ 5700RPM per our previous email conversation about my timing where it was recommended I pull 2 degrees from 15psi upward throughout my midrange to redline. AFRs are 11 - 11.4 to 1.
If adding timing in the surrounding RPM and load sites didn't help and you are not getting any knock retard then this is a mechanical issue.

Thanks,
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Old 01-12-2006, 10:16 AM   #38
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Check your calibration on your wideband too... make sure you're really running 11:1 and not 10:1
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Old 01-12-2006, 11:09 AM   #39
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Do this one thing, if you haven't already:

Run a GND, preferably a large copper-stranded cable, to each valve cover bolt.

I'm curious.

If you end up needing to "borrow" a set of coil packs (or one for testing), let me know.

S.
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Old 01-12-2006, 01:00 PM   #40
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Quote:
Originally Posted by DarthChicken
Check your calibration on your wideband too... make sure you're really running 11:1 and not 10:1
Are you seeing fluctuations Adam. Mine's been out of the car so often that I recalibrate and have not really logged if the sensor has changes. Trent
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Old 01-12-2006, 01:35 PM   #41
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ride5000: *kick*

DarthPoultry: WB02 was free-air calibrated 1 month ago. It reports the same AFRs it has for months, so I don't think that's it.

Two months ago I tried tuning this out for the first time. I was running my HR7 NGK iridiums then (mentioned only for completeness). The hesitation was there at 13psi and any timing between 17 and 21 (@5700RPM). I left it alone for the time-being, 90% convinced it wasn't knock so could wait.

Per email conversation with Phil a few weeks ago, I dropped my timing to pretty much 15-17 degrees from 4500-7000RPM (14psi and higher).

For last ditch giggles last night I dropped my timing in the 5600 and 5800 cells from 15 to 14 degrees and then could not reproduce the hesitation during 4 more pulls. Parked the car and grumpily channel surfed from the couch.

I'm still not convinced of anything. I will start another round of flogging the car with the current settings and report back again. If it's still there, I'll pursue grounding and digging up the coil pack testing procedures.

I'll have this engine completely shot by the time I get it tuned completely
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Old 01-12-2006, 03:04 PM   #42
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If lowering ignition timing cures the misfires, all this is means is that your car doesn’t misfire at lower cylinder pressures but it does at higher cylinder pressures. As soon as you increase cylinder pressure with boost or timing the problem will return. If replacing the spark plugs temporarily cures the problem, it’s a spark energy issue. Subarus with healthy OEM ignition systems don't have significant misfire issues until well over 600 whp.

Now improving the grounds can help if you have a grounding issue which I have seen on many Subarus but it will not improve anything if the grounds are healthy. I would say this is worth testing but you can usually see this problem by monitoring the voltage readings in the Hydra.

Try giving your keys to Garry Sheehan for a day and really understand what ragging out your car out is all about

Thanks,
Phil
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Old 01-12-2006, 03:12 PM   #43
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Gotcha.

FWIW, this problem persists no matter the plugs (even hr7 coppers).

I will put the degree of timing back in the respective spots and monitor voltage then as a start (and start digging up the coil pack testing procedures/specs).

In addition to my Sebring day, I have to be well over 100 additional WOT pulls to redline from tuning alone by now.
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Old 01-12-2006, 03:51 PM   #44
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Anyone looking to buy a WRX?

* Runs like a top below 5700RPM. You shouldn't need to rev higher anyway on public roads.

* External lubrication system - Weeps 1 ounce of oil a month out of the driver side valve cover.

* Environmentally friendly! Breathes so well it requires a catalytic converter to stop boost creep.

* AFRs fluctuate from 14.0:1 to 15.0:1 at cruise around 2800RPM and rock-solid-same vacuum readings @ 410mmHg. Roughness keeps driver alert and annoyed -- no more sleeping at the wheel!

* EGT probe last functioned 1/6/2006. More voltage delivered to ignition system!

* Kenwood MP3-CD player no longer plays any bulky/heavy CDs! Weight reduction for optimal acceleration.
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Old 01-12-2006, 06:04 PM   #45
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Quote:
Originally Posted by Element Tuning
Try giving your keys to Garry Sheehan for a day and really understand what ragging out your car out is all about

Thanks,
Phil
http://www.elementtuning.com
Seriously... look at what he did to my tires at Thunderhill!!



Okay, back on topic people.
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Old 01-12-2006, 06:36 PM   #46
bboy
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It seems to me if you have never done any tuning that increased the misfiring, then tuning it out seems less likely as well.

Both Phil and Steve seem to be pointing toward coil packs/spark energy. Maybe that is it. Can the packs be tested--you have certainly ruled out the plugs.

For what it's worth I did improve my crankng voltage according to the Hydra by moving the ground on the starter from the tranny to the block (by half a volt). I was surprised by that.

Mental note: Gary Sheehan not to drive my car.......


.....but it's Gary Sheehan driving your car!!

Last edited by bboy; 01-13-2006 at 12:10 AM.
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Old 01-12-2006, 07:35 PM   #47
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Any tuning I've done has neither increased nor decreased the hesitation.

It remains present and remains intermittent, but always at ~5700RPM. The car continues from there, at the same timing, AFR, and boost... all the way to redline happily.

New EGT probe installed just now. Yay.
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