HE351 code for me78569

[me78569]

I will look.  This is a whole new world for me so I think I do about 1 line of code for 5 hours reading haha. 

[hakcenter]

The response back from the eml37 for rpm, could range from 0 to greater than 255, so you would want to catch both.

You might get 0x03, then sometime later get 0x01 0xff or something. I put that crude reply so it would make more sense written out, you totally don't have to do it that way, just put it in a for loop.

And 00 00, is 2 bytes. But if the ECU does not give you 00 0F, but 0F instead, you would want to catch the 1 byte reply.

[me78569]

Thanks!

So I have been struggling to figure out why my shaft speed stopped working all the sudden.  Finally found that the 5v on my shield was no longer producing 5v, after I replaced the 9924 with a spare I had, redid all the wires and ohm'd out all the wires. 

Well now I can't read shaft speeds under 40,000, just reads 1000, or 2000, then you hit 40,000-50,000 and it reads great.  Very stable and more jumping etc lol.    seems that I changed from having bad reads above 80,000 to having no reads below.

So who know, gonna have to go back and review all the stuff I have,.

[hakcenter]

Weird

[me78569]

REdid all the grounds / 5v resistors on the 9924. 

It is almost like when a hall sensor goes back and it won't read unless there is a lot of movement.  I am almost wondering if the turbo speed sensor is bad. 

I need to verify one other thing tomorrow before I go looking for a new shaft speed sensor. 

[65fpvmustang]

my turbo speed sensor slowly stop working switched to spare same thing. worked ok at high shaft speed but dead blow 40k. seamed to get better when engine was warm. changed motor oil and it came back. haven't had a problem in 6 months or more i think it was a build up of zddp additive. i run a lm1815 circuit feeding to mega squirt.
it was driving me nuts a changed the lm1815 circuit.  I could take the sensor out and hold it next to alt fan and it would read great. put it back in turbo crappy signal again. good luck i know how frustrating it can be.

[me78569]

I am overdue for an oil change.  I had that thought too.

I'll do that tomorrow I guess...

[me78569]

oil change done, same issue.  ( oh well needed to be done anyways)

Anyways issue was that the butt connector I used to connect the VSS harness ( soldiered first, but wires busted) were not working.  I resoldiered the wires in the harness and bam issue fixed.   Not sure why that matters, but oh well.

[me78569]

finally got my shaft speed issue fixed.  Ordered a new sensor, same issue.....ugh

I found that the solder joint was causing too much resistance in the wires causing it not to read.  I cut out the wire and recrimped the ends in the plug end and blam issue fixed.

[hakcenter]

Noice

[me78569]

Also my top end jump issues are fixed.  I am now seeing stable shaft speeds above 80,000.  I am also struggling to push speeds above 120,000 in my current code.  Very excited to tune some more now.

[me78569]

Made a holiday trip to my moms house up in north minnesota, AKA sea level.  I cannot say how much I hate living at 7000' in altitude. 

with my 100 injectors and my quadzilla turned up my truck is all but smoke free at 450 hp worth of fuel at sea level, at home my truck smokes like a train.

I could EASILY pass emissions with the fuel turned up if I didn't live at 7000'


I did notice that my boost and drive sensors were reading high at idle, due to more atmospheric pressure.  I have added some to my code to adjust the boost and drive values by comparing idle state boost to recorded boost, IE: at idle boost should read 0 so if it is reading more or less I can adjust.

Here is the timer trigger

Code Select Expand

if (timer % 800){ //checks for idle state to run the barcalc section, which corrects the boost and drive sensor for altitude changes.
    if (ThrottlePosition = 0){
      barcount ++;
      if (barcount = 10){
        baroffset();
      }
    }
    else { barcount = 0;}
  }

Pretty much if TPS is 0 for 10 times through the timer section it will run baroffset();

Code Select Expand

void baroffset (){                                         // compares idle state boost to 0 psi so altitude isn't causing miss readings.
  barcount = 0;
  barcalcb = 0 - BoostPressure;
  barcalcd = 0 - ExhaustPressure;

}

Then  I adjust my boost and drive reads.

Code Select Expand


  if (adc_roll_over == 1) { BoostPressure = ReadBoostPressure() + barcalcb; }
  if (adc_roll_over == 2) { ExhaustPressure = ReadExhaustPressure() + barcalcd; } 

[Rx7man]

Altitude compensation is tricky... Depending on the sensor (absolute, sealed gauge, or vented gauge) will change how you go about it...

Honestly, I think you should be keeping the boost control logic using an absolute pressure reference (uncompensated for altitude), but compensate it for 'display' purposes...
At the end of the day, you want a certain *absolute* manifold pressure to burn a certain amount of fuel, and that doesn't change with altitude, but your boost gauge will read differently... At sea level, you probably need to run 30 PSI boost (44.7psi absolute ... 30PSI +14.7).. while at 7000 feet you would need the same absolute pressure (44.7), but your boost to get it would change because of lower atmospheric pressure.. Lets say there's a 4 PSI change from 0 to 7000 ft (wild guess).. Now you'd need 34 PSI of gauge boost to get the same 44.7 PSI absolute pressure (34+ 10.7).  Since your sensor is changing it's reading depending on your elevation, I'd go out on a limb and say it's either a "sealed gauge" or "absolute" style, either are fine... the "vented gauge" types will read the same as your in-cab gauge, the other two will change with elevation.

I'd consider not changing the boost level for elevation!

[me78569]

Thanks for the insight,

My boost readings don't really do much in the tune.  It will adjust the vanes somewhat at lower boost and high tps input to help spool but other than that it isn't really considered significantly. 

I was thinking of just editing the display, but I am a little bored and I figured I might as well try and adjust it fully haha.

[Rx7man]

Have fun with it.. I am having lots of fun, trying to find things that work, learning from what doesn't.. sometimes things defy what you think is logical, and then you gotta figure out why.

Without a dedicated atmospheric pressure sensor, it'll be really hard to accurately do any compensation.. My truck typically makes about 1-2PSI boost at idle, so I pretty much can't use that sensor for squat.. I'd have to have a MAP sensor before the turbo, and with that I could calibrate the other one when the engine is idling, and display air filter restriction any other time... I do have a spare MAP sensor.. perhaps I'll do that for shits and giggles.