Accel Enrichment and tpsDOT

[portmod7]

Hi guys,

MS-II v3.0 with v2.905 code. I have a FAST throttle body with a variable TPS.

I'm attaching my datalog and MSQ. They aren't going to be that great for really nailing down tuning issues because throughout this datalog I was adjusting the settings on the Accel Wizzard in TS (both the graph values and tpsDOT threshold). But the reason for this post is that after looking at the datalog, the tpsDOT and accel enrichment graphs seem to be erratic to me. I don't really see an issue with the TPS signal itself, but it seems like something in the calculation of tpsDOT is wrong or something. The TP graph will show an aggressive spike which seems right, but the tpsDOT graph will show 0 or close to it during that time, which doesn't seem right to me.

Also, this is the first run where I've had tpsDOT threshold set lower than 200%/sec. Again, I failed myself in that I was changing too much in a short period of time hastily trying to get the acceleration tuned better, but it has started stumbling at slight throttle tip-in. For an example, look at time 2456.103 on my datalog. TP goes up, PW goes up, but tpsDOT and AccelEnrich both go down and AFR goes lean. I don't understand that at all. And tpsDOT shows a net value much higher than I would get with much more aggressive throttle application at other times.

The engine really seems to run fairly well most of the time, but throttle application is erratic. Some drives it's pretty good but some drives it's horrible. And taking off from a dead stop is always a crap-shoot. The TP signal doesn't seem to be erratic, but tpsDOT and AccelEnrich seem to be.

Any ideas? My next plan of attack is to get much more methodical with my tuning. I thought I could hastily get it running quite a bit better with some quick adjustments and fine tune from there, but it's just not working. Also, approximately the last 5 minutes of the datalog actually correspond the the MSQ I've uploaded. The only difference earlier in the datalog are the acceleration wizard settings.

Thanks for your help!

[Matt Cramer]

The trace looks fairly normal to me, keeping in mind that the slow rate of the serial data logging means you won't always capture all the spikes since it is possible for a rapid opening to happen completely in between frames.

[portmod7]

Thank you for the quick reply Matt. At least I know that I don't have something to fix, other than tuning.

Is there a way to increase the rate to get a better picture of what's happening to help me tune, or is this just the way it is?


Thank You!

[portmod7]

Found it, it was under the communications tab. I bet a rate of more than 1/sec will help the situation a lot.