Some Datalogs of a Stock DSM

Unfortunately, I've lost/deleted any of my older datalogs of the gold Laser, from back when it was still stock.  It'd be nice to have something like that, to keep for future reference and comparison.  I finally got a laptop and datalogger cable (to replace the old ones that got stolen), so here are some logs for the white car.

Here's a basic WOT run on pump gas.  Just like my first datalogs of the gold Laser, the white one, in its current condition, has a lot of knock.  It seems to be occurring just in 1st gear.


Unlike with the gold Laser, when I put in 100 octane unleaded, the knock doesn't go away.  The fuel gauge was just below the "E" tick, and then I put in a quarter tank of 100, so we'll call this 99 octane.  I drove just 1.5 miles between putting in the gas and making this log, so hopefully it got mixed enough.


Those 99 octane runs were done on about a quarter tank of gas.  The knock often doesn't start right at the moment of going WOT, but would instead be about 1/2 second later.  I kept wondering if maybe the knock was from the gas sloshing back away from the pump.  So I tried again with more like 1/2 tank.  No such luck.


There's some phantom knock, too.


Here's a puzzling occurrence.  For some unknown reason, the IPW momentarily dropped to nothing, and seems to have triggered some knock.  This is with the car's original California-emissions ECU.  Did the ECU really stop putting in gas?  Or was it an error getting the data to the logger?

Here's the data where that IPW drop occurred.


FWIW, here's a run with a stock Federal ECU swapped in.


Back to 93 octane and the Calif. ECU.  If I gradually roll onto the throttle, the knock seems to be less.  I suspect the knock is probably due to carbon deposits on top of the valves, which would initially soak up some of the fuel that should really be going into the cylinder.  If so, this could be cleared up by an MCCC cleaning.


One of the other problems the gold Laser originally had, was that the O2 readings had a zigzag pattern imposed on them.  I think this is caused by dirty/imbalanced injectors, and I fixed it on that car by having the injectors cleaned/balanced.  Looks like the white Laser has the same problem.  I may swap in my old 450's that were done by RC.


The current injectors don't seem too bad, though.  By giving it just a little gas to idle at 2000 RPM, the O2 cycling becomes smooth.


Here's a view of it switching from closed-loop to open-loop, with the stock ECU code.