On 05/08/2011 12:23 PM, Steven W. Boese wrote:

Maybe the MS isn’t doing you have told it to do, or there is another parameter that is changing.  One possibility that comes to mind might be the fuel pressure not remaining constant during the test.  Constant fuel pressure might be something worth verifying since if it is not, the fuel pressure regulator, fuel filter, fuel pump, or other component of the fuel system may be at fault.

 

I'm not going to do to much with it for the rest of this week, 'cause I've got a few other things on my plate, but, as I partially stated, the test were limited by two factors.

First, the software was flaky, forcing me to have re-burn the firmware.  It was so bad that for the test of the secondaries, I just ran a test with the default settings.  I wasn't able to produce a range of repeatable results, so the tests are suspect.  I'm trying to get in touch with the developer to get better documentation, and possibly help him improve the workflow of the process.  The whole injector test should be a self contained wizard that feeds tuning parameters back into the rest of the program.  The guy has already done all the hard work, so I think I'll be successful.

Second, the resolution of my measuring device was crap.  What do you expect from Wal-Mart?  I bought them before I had done any tests, and was unsure of just how much fuel they would have to hold, or how accurate they would need to be.  Before testing again, I'll buy a couple REAL graduated cylinders.  I also had a digital scale with a 10g resolution.  That was pointless 8*)  Maybe this is my excuse to buy a digital scale?

I did run the numbers on the two test runs that were repeated several times.  The 400-20msec, and the 1600-5msec samples.  The injector turn-on time came out to be 1.152msec.  "turn-on time" being defined as a derived number that represents no flow out of any given cycle time due to the cumulative effects of opening and closing the plunger.  The number is suspect, but very reasonable.  The default tune setting for this parameter in the software is 1msec.

The other useful indication from this test was that the paired injectors are flowing equally.  Regardless whether I was spraying the counts or cycles I thought I was spraying, the fact is that the driver circuit handles both injectors in the bank equally, and they are supplied from the same rail.  Even if I misread the volume, the fact that they're at the same line says the flow rate is equal.

If ya'll ain't noticed, I'm having way to much fun here.