..... On drag strip runs , I am experiencing an intermittent AE ( pump shot ) ... some times ( about every third pass ) it goes rich enough to cause a serious stumble when the loud pedal is matted , thus causing a generous increase in reaction times off the line in the .220 range .... generally I can keep RT's in the .030-.050 range ... I'm using Tuner Pro RT and $32B xdf ... AND occasionally , it goes lean first (15.30's) with a weak AE following ... What can be causing this ?? ..........

 

Fuel delivery issues will do it.

The other is the TPS setting. Check a data log and see if it is also dropping out of PE mode. The MAF code is sensitive to a too high of a TPS voltage at WOT. It will do an internal default and also drop out of PE mode. Most likely will also drop out of AE, as it too depends upon the TPS value.

RBob.

 

..... New high flow pump in April new filter , nearly full tank ... TPS goes to 3.70 volts at WOT and stays there ........ .52 at idle ... I'll have to data log for AE drop-out ... $32B doesn't show PE .......

 

Some of the PE/WOT tables are not included in the default $32B XDF. You can try the one I made here if you'd like. Put TunerPro into "Parameter Category" view and I have a PE/WOT category that calls them all out.

https://www.thirdgen.org/forums/diy-...efinition.html

Or do you mean you can't see if it is in PE mode or not with your datalogging?

Also 3.7V at WOT sounds a bit low. Even though you only need ~70% of 5.0V (~3.5v) to go into PE, mine goes to about 4.7v with the TB wide open. Can you put an anallog voltmeter on the TPS and see if the gauge arm goes up smoothly while you manually open the throttle?

 

..... Made some passes last night ... datalogging was a pain , but I did see that my Lv8 is changing ... at pedal stomp its 255 ... next sample its down to 162 ... then gradually increases to 208 at around 2700 rpm ... this is the first indication of road speed ... 1 mph ... then it holds through first gear in the 220 range ... As I would expect , the afgps also goes down at first ... so does the bpw ... and timing goes up ... all following the Lv8 changes and the maps since SA and BPW tables are multi-dimensional ..... AE seems to appear at variable rpm's and intensity ... again following 2D BPW tables ... SO where to go to smooth things out ... its not wheelspin or I'd see mph ... I pulled the trans pan in May and it was beautiful inside so I think not the tranny ... I have a 2500 rpm stall converter that flashes to almost 2800 around where my road speed and Lv8 start to appear ... at the stomp to move range I see AFR spikes that can't be smoothed in the WOT vs RPM tables ... Oh , and no spark retard ... I also tried a different MAF sensor with the same results ...