High rpm bogging
 

Long history in a short period. NA engine rebuilt after rocker arm/timing chain issue. What would cause the ignition timing advance to drop at wot? Still waiting for my tuner to get back to me.



https://datazap.me/u/blsfrs/log-1644...&data=10-20-21

Funnier behavior. If I push the pedal 3/4 (under load, 2nd and 3rd gear pulls) to the floor, the rpms go from 3000 to 7300, no problem.



If I push the pedal 4/4, at around 5000, the engine bogs like hitting a rev limiter and my ignition advance drops to 3*-5*. The point that the advance drops can vary from 4500 to 7000.


Are there any diagnostics I can do while waiting to hear back from my tuner, Said he's going to look at my logs this weekend.

Did something get changed in the tune recently or is this just since the rebuild?

is it running lean??? or rich??? when you go to full throttle it uses a different part of the map, but something physical or in the tune is off.... not getting enough fuel???

Here's the timeline (and I didn't even mention the broken driveshaft).


March 2021: Ingested something in #3. Ejected intake rocker arms, broke timing chain. Complete rebuild by Cody Dawson. Injectors serviced by Injector Pulse. Engine reinstalled September 2021



PROBLEMS SINCE REINSTALL


Intermittent P0219a and P0119f (AFR codes) and decreased power.



Replaced: MAF, MAP, upstream 02 sensor. No change.


January 2022: PTuning: No problems found. Retuned. NEW PROBLEM: Upon picking car up, found bogging at 5500-6500rpm. On the way to Charlottesville the CEL for secondary 02 came on but hasn't come on again. No improvement with replacement of throttle body.


February-March 2022; Bogging/decreased power worsened to the point where the car wouldn't go over 35-40 mph. Upstream cat removed after temp/back pressure tests. Immediate improvement in power up to 6000rpm then bogs like hitting rev limiter. Sometimes improves with 3-4 3rd gear pulls but bogging returns next drive cycle. Installed Nameless 2.5" catted midpipe: No change in bogging. CEL for P0219a and P0119f came on last week.


A couple of weeks ago went back to PTing. Their guy could not reproduce bogging. He then rode with me and I reproduced it with him in the car. He and their tuner went out to data log but could not reproduce bogging. I finally was able to send them an Ecutek datalog and am waiting to hear back from them.

Tuner at Ptuning says everything looks good.

Can you log what the sensor voltage outputs are in Ecutek? I wonder if you have something going out or range on the higher end. Also hard to tell if it is picking up any knock and that is why it is pulling timing, though I doubt this is the case. I'd imagine the PT gus have looked at that already. It's hard to tell what's the chicken/egg.

Here is the Ecutek log. I mostly don't know what I'm looking for but I can see the ig timing drop. Any Ideas? Thanks



https://datazap.me/u/blsfrs/log-1651...og=0&data=7-12

That is strange. I was hoping to see a hardware issue pop out but maf is stable as is afr so I doubt the O2 is acting up. KC is 0 with a tiny bit of KC learned. We are over my head. Maybe Tomm or Steve will chime in. I wonder if something else is causing the timing compensation table to wig out and drop out the advance. Any missfires? It for sure can't rev out with it pulling timing that far out.

Lately this car has cornered the market on strange. I get no indication of missfires. As I said earlier, if I hold the pedal at 3/4, it will rev to 7300rpm. If I really floor it , it bogs.


I noticed that none of the PTuning drivers seemed to change my seat position. I have long legs. So, I question if those drivers could push the gas pedal as far as I can. Also, the car was tuned with a failing cat.

AFR looks too rich at high RPM. Way beyond needed. Out of the range that the stock O2 sensor can handle.

What is going on with the DI from 4.5 to 5.5 seconds into that log? Fuel rail pressure too. Like an intermittent electrical something cutting out from vibration. Red herring? it doesn't happen in the second pull. I'm always afraid to join in on these discussions.

Something is quite off mechanically/electronically, also we can t see the tune or if he used custom maps too so really can t help, just look to me that something is too off to be tune related

Good observation. I didn't see that before. It looks like the afr goes rich when the timing advance drops. Maybe it unburnt fuel as a result of lack late spark?