Skydive@AI

I'm tired... so I may very well be missing some important points, but here we go.

Diego was good enough to copilot again tonight while we experimented some.

Here are tonight's logs:

<A HREF="http://www.pacificnet.net/~mklenner/Stuff/Logs/Typical-11-28-2004_5-49-22_PM.csv">Log 1</A>

<A HREF="http://www.pacificnet.net/~mklenner/Stuff/Logs/Typical-11-28-2004_6-12-58_PM.csv">Log 2</A>

As you can see, one of the longs is small, and truncated. I'm not so sure how much good data can be found in each. We hit traffic in several spots.

Our proving ground was different tonight but we tried for similar grade, so we could compare apples to apples.

Both logs do include OXS Voltages.

According to Diego, everything looks good and within spec, except I'm still pulling timing, and we can find no correlation to explain that.

I did gain about 5 degrees BTDC by running the 93 code on ordinary 91 gas. Interestingly, the knock sensors stayed quiet, and safe. (Ambients were low, though.)

We tried to add a few degrees of timing for purposes of diagnosis, and found that the ECU would simply pull it all back, (so instead of pulling 8 or 9 degrees, I'd pull ten or twelve.)

I'm not entirely sure where A/F ratios typically live in the APR world, but according to Deigo, these ratios are spot on, in a GIAC context.

Ideas?<ul><li><a href="https://forums.audiworld.com/s4/msgs/1828906.phtml">Here's a link to yesterday's conversation and theory.</a></li></ul>

Hal_TT::CBP

Hard to read/trend when the first 4 are in one place and 5/6 are a few columns away.

Couple of questions: at block 106 and 156(06-12-58 log) assuming this is TC and not a lift correct?
Are the injectors oriented correctly? Think the drivers plugs face toward the firewall and the passenger ones face the grill iirc. Need to check I may have it backwards...

890s EGTs look ok but its pulling the crap out of the timing. How does it feel drive-wise? Crisp or sluggish on the pedal? I am thinking fuel as well but defer to Diego on the final assessments on this. Have you checked/read the plugs? Any black smoke in the lower rpms? Do you have cats? What does the exaust smell like? Rich or lean when you rev it at rest?

Sorry for the ramblings. Sounds as if the car thinks the injectors/fuel is maxed and it is protecting itself.

Skydive@AI

I haven't tried to re-order things with ECUx. It may be possible, but you could easily cut and paste columns in the CSV, if it's easier. I can try to do it tomorrow morning, but I am exhausted tonight.

It could easily be a lift. We were floating in and out of traffic. We didn't feel, nor detect any significant throttle cut.


According to what I've read, EGT related timing correction is controlled only by the "true EGT" sensors, not the pre-cat O2 sensor EGT data. The true EGT sensor range starts at 1733ºF, (945ºC) and that's where they are throughout tonight's pulls. Enrichment based on EGTs does not begin unless and until temperatures reach at least 980ºC.

Throttle response is fine, and I'm actually spooling to full boost by 3,250 RPM, which is pretty good, but the car feels slow.

I detect no black smoke at WOT, but it would probably be best to have someone observe from behind me, since I have decent tint, and might be missing it entirely since these logs are night logs.

Occasionally, I detect a slight sulpher smell after extended WOT activity.

I'm at my wits end.

Diego's context is based on what Garret feels is safe, and I'm sure APR has different ideas... but according to Diego, A/F ratios are good. I would love to work this through with some logs from a "known good" APR car...

-Michael.

Hal_TT::CBP

or do some 100% throttle pulls to see if that is not TC(need to make sure the foot is planted for the run)? Dave graphed the previous ones and it looks like TC in those.

Also are you sure you have the latest code? Initially the post-A(M/T code, don't know what tip code corresponds with this box) had TC that was ressolved with the 1.2 release... you may have documented this earlier but want to be sure since this could be the easy fix.

I have logs from a H and M box Stg3, neither local cars though, that the timing is much better on them. One of them had an EGT sensor that was bad but there were CEL codes occasionally with this one.

DAP@EPL

around 1.0 bar instead of the requested 1.2 bar. Lower boost and MAF means lower engine load. That is why timing is up for that run. Your injector duty cycles peaked at around 80% that run due to the lower boost.

In Log 2, looks like you had to lift mid-run and then got back on it. In that run, timing was back down closer to where it was in yesterday's data and the injector duty cycles were back around 90% peak.

I don't really have any suggestions or ideas as to what might be wrong, but I don't thing the 93 octane code helped much. I think the low boost made it look like it was helping since timing was higher.

-Dave Pramanik

Skydive@AI

We didn't log the 93 code. Both runs are 91.

Skydive@AI

FATS is completely different on Tip cars. I don't think it's a good reference.

DAP@EPL

Ah, gotcha. Well then disregard those comments.

Skydive@AI

...perhaps there is a communication between the TCU and ECU and the car cuts timing to restrict torque, under high load conditions. One of the folks at IW did some research that suggests that the system intentionally pulls timing at shift time, to protect the transmission. Perhaps it's a constant condition once you get to these power levels.

I know I'm grasping at straws, at this point, but I'm out of ideas.

Hal_TT::CBP

above on the shift points and such with the ecu. Sorry I don't have any knowledge/experience when it comes to the TCUs...