I don't know whether this is a tuning / configuration issue or a software or firmware issue; but, I am going to start with tuning / configuration.
I was doing a datalog during a start and warm-up as part of tuning my start-up parameters. While scrolling through the datalog, I came across this oddity. The engine is at idle; but, the TPS must have vibrated slightly or picked up an errant signal somehow which registered as a brief drop in throttle position from -0.3 to -0.6 % (green line - top trace). What is confusing is that the drop in throttle position registers as a + TPSdot (yellow line - top trace). I have seen these small TPS transitions before and negative transitions have always registered as a - TPSdot. In this particular case, the TPSdot value was above my threshold value of 20% and triggered accel enrichment (red line - top trace). This appropriately resulted in an increase in PW (red line - bottom trace); but, there does not appear to be any attendant disturbance in the AFR signal (yellow line - bottom trace).
My primary question is, what could cause the positive TPSdot in response to a negative throttle transition? As a secondary issue, any thoughts on why the change in PW did not show up as a disturbance in the AFR? The PW changed from 5.5 to 7.2 for approximately 0.3 seconds which is not insignificant and should have shown up in the AFR.
I have the full log available if someone is bored and wants to peruse.
Unusual TPSdot event
Forum rules
Read the manual to see if your question is answered there before posting. Many users will not reply if the answer is already available in the manual.
If your question is about troubleshooting, configuration, or tuning, you MUST include your processor type (MS-I or MS-II) and code version in your post. If your question is about PCB assembly or modifications, you must also include the main board version number (1.01, 2.2 or 3.0). For tuning/troubleshooting questions, please attached a datalog and your MSQ file to your post.
If you have questions about MS1/Extra or MS2/Extra code configuration or tuning, please post them at www.msextra.com Such questions posted here will be moved to: a temporary MSextra sub-forum, where they will be removed after 7 days
The full forum rules are here: Forum Rules, be sure to read them all regularly.
Read the manual to see if your question is answered there before posting. Many users will not reply if the answer is already available in the manual.
If your question is about troubleshooting, configuration, or tuning, you MUST include your processor type (MS-I or MS-II) and code version in your post. If your question is about PCB assembly or modifications, you must also include the main board version number (1.01, 2.2 or 3.0). For tuning/troubleshooting questions, please attached a datalog and your MSQ file to your post.
If you have questions about MS1/Extra or MS2/Extra code configuration or tuning, please post them at www.msextra.com Such questions posted here will be moved to: a temporary MSextra sub-forum, where they will be removed after 7 days
The full forum rules are here: Forum Rules, be sure to read them all regularly.
Unusual TPSdot event
You do not have the required permissions to view the files attached to this post.
-
kjones6039
- Master Squirter
- Posts: 618
- Joined: Sat Jul 22, 2006 7:02 pm
- Location: Eureka, Nevada USA
- Contact:
Re: Unusual TPSdot event
OK....... You have my attention now! Now I want to see your actual log! 
Ken
Ken
1979 Corvette - 383 CID SBC w/ Holley Pro-Jection 900 CFM TBI, 4-85 lb lo-z injectors & Walbro 255 pump
MS2 v3 w/ms2extra 3.4.0 Release
36-1, Delphi LS2/7 coils in wasted spark, driven by v2.0 logic board from JBPerformance
Spartan Lambda Sensor from 14point7
MS2 v3 w/ms2extra 3.4.0 Release
36-1, Delphi LS2/7 coils in wasted spark, driven by v2.0 logic board from JBPerformance
Spartan Lambda Sensor from 14point7
Re: Unusual TPSdot event
I have attached the log. The event in question occurs right around record 722 (57959 seconds).
You do not have the required permissions to view the files attached to this post.