'm afraid my anolog to digital converter might be dead or it might be something I need to change.I know that the TPS and MAP share a common 5v reference signal. When I power up the board on megatune the TPS and the MAP range are both at 100% and they slowly drop down consistently together until they get to about here???????
(http://myweb.cableone.net/mjbless/vems/mt.jpg)
First of all, check that you have alphaN turned off. (This effectively makes MAP into a scaled version of TPS) The settings are lurking somewhere at the bottom of the settings menu - something like "AlphaN blending". They should be set to high numbers.
Then check the grounding, suppy and resistance of the TPS. I've not seen A to D failures in VEMS where the signal drifts around. It normally gets stuck somewhere and just stays there. It's usually something on the analog side playing up - perhaps the 5v regulator if the above don't work.
My settings
(http://myweb.cableone.net/mjbless/vems/alpha.jpg)
The 3rd pin from the right on the MAP shows a solid 4.94 and doesn't change
**edit**
AH HA!
I'm getting no voltage at all on pin 29 which is supposed to be the 5v out for the tps.
So this basically means that i'm now stumped :-\
Is this a system you've built yourself? If so check that the resistor between pin 28 and pin 29 is in place. The TPS feed has a resistor to make it a 'weak' signal.
I've been known to use Pin28 to feed all the required +5V signals.
Yes this is a V3.2 board that i assembled.
It looks like theres nothing there. Since i've already got it pinned in on the connector i'm assuming i can just bridge the two terminals to give my TPS the 5V signal it needs?
Oh, I tried re-uploading the firmware and now get this.
(http://myweb.cableone.net/mjbless/vems/mega.jpg)
I redid the process step by step with the 12x12 version and i still get the exact same thing. Man i'm on a roll tonight.
Don't bridge it with anything other than a resistor of the right size. The one on a board I have here says "271" on it.
Stick with the 12x12 for your initial tests mate, start simple and add complexity.
You'll find that the 12x12 is pretty much all you need except on a small cammy engine where you might need some additional interpolation at the low end.
Ummm same exact deal with the 12x12. You know....Maybe this has something to do with the map sensor itself. It does say that theres a difference in kPa values. Hrmmmm
(http://myweb.cableone.net/mjbless/vems/12.jpg)
And just to verify what we're talking about Is there only 1 resistor used between them or is there two?
(http://myweb.cableone.net/mjbless/vems/pin.jpg)
Depending on the application, there's different MAP sensors and different scaling factors. These do need to be matched in the INI file and the VEMS itself. You need to look in the ProfileActivation folder and make sure the correct boost profile is selected.
It is quite likely that the version of Megatune and the Firmware in your VEMS are not compatible - especially if you have recently downloaded a new MT and the ECU is a 3.2. This means you should reflash the firmware in the VEMS. Rob has written some good instructions for doing this (available in the "software" forum) , so I'll not go into it here. This should clear up the MT error message.
I'll let Rob deal with the soldering issue since I don't have schematics to hand.
Quote from: bcool on October 23, 2007, 12:18:43 PM
And just to verify what we're talking about Is there only 1 resistor used between them or is there two?
(http://myweb.cableone.net/mjbless/vems/pin.jpg)
One resistor on the bottom pads, this pulls the pin up to 5v through the resistor. The top pads would pull the pin down to ground.
Ignore the 2,4 error, go into the basic settings and correct the boost option to suit what you're running.
I think 4 is insane boost. You want high boost which will report 2,2
Rob
Weird i dont know how that got changed to the insane setting. I switched it back to default and all is well now.
So i'm assuming just soldier it up in this configuration?
(http://myweb.cableone.net/mjbless/vems/tps.jpg)
K got that on now i'm getting a clean 4.93V
Alright down to the original question....what the hell is up with the TPS and MAP on my megatune.
When I see that sort of behaviour its as if the sensors are not connected. Follow the voltages into the A2D converter and try pulling up or down the lines and monitor the voltage and behaviour of the MegaTune dials.
OK now this is weird. I have it connected on the car now. I dont see the TPS or MAP dropping down from the 255kPa value and the 100% tps value, so they stay stable there, but what is weird is when i i apply throttle about half way through my throttle position range the TPS AND the MAP both start dropping their values at a consistent rate together until my foot is to the floor
Here's the video of said action:
http://myweb.cableone.net/mjbless/vems/tps.mpg
Okay so possibly a great breakthrough. I dug up one of jason's more recent config files and input it into the ECU just to test it for cranking. In doing so I now have a working TPS. I can make full sweeps from 0 to 100 now that it's calibrated. I still dont have a working RPM trigger though. well not that i can see anyways. The only thing that seems weird to me is that the MAP is locked at an even 100 kPa. What should i look into for this?
Heres my old config file:
http://myweb.cableone.net/mjbless/vems/configbackup.txt
And the new config i put into the ECU:
http://myweb.cableone.net/mbless/vems/config.txt
I changed the Maximum kPa to 250 and the offset to 0 and It hovers somewhere around 23 kpa and when i blow/suck on the vacume tube it does not change. In his notes of him using the config file i have he says that he has been experiencing a similar issue.
QuoteCan someone give me a hint at what to look at to solve these problems bench testing (firmware 1.0.69):
* MAP doesn't move with pressure changes
o Pin 3 has 4.97V, pin 1 is ~1.8V -- seems right, just not represented through the AVR
o Calibration in basic settings (kpafac), depending on map sensor range, fine tune with offset
+ I screwed up the map sensor range and the kpa fuelcut settings somewhere along the line, fixing that solved the MAP problem and the injection problem too.
* Fuel injectors don't fire
o There's +5V at the input of the injector driver, 0V on the output of the injector driver (no pulses from the AVR).
o caused by the bad map sensor calibration in combination with low kpa fuelcut
* Setting up IGN_DUAL_OUT for channel 0+1, and 5+6 only 1 and 6 flash with signalgen trigger applied
o Broken in firmware 1.0.69, run 1.0.71 instead
+ Going to 1.0.71 worked wonders. Thanks! I added a note to the 1.0.69 section of the firmware page too. It was there, but I added it in a more logical place for me at least.
What should my pin 1 (econoseal 18 side) be reading for voltage on the MAP? I have a god solid 4.95V on pin 3 and 0.44V on pin 1, and 1.14 on pin 6 (FET/IGBT side) infact i tested all of them with vaccume and none of them make any noticable voltage change even down to a hundredth of a volt . I mean how wide of a voltage sweep should i be getting here?
Pin6 on the EC18 plug on my test ECU is 4.5mV
The trouble with these self-build ECUs is that the only place where they can be correctly supported is on the Wiki.
True. Well I got another MPX4250AP map today and installed it. I'm still stuck with it hovering around 23 kpa so once again i'm stumped. Jason had me short the 2 pin blobs above the Keyboard pins on the board and still there's no difference. Unless i missed something in the configuration somewhere. ??? ??? ???
As long as you havent got AlphaN blending set you should see a proper kpa value...
AlphaN stuff is set to
0
0
and Disabled hrmmmm
Thats the setup for a MAF sensor (experimental code - dont use it), you need Multiplication set to Enabled.
All the air metering options are near the bottom of the User Guide
http://www.vems.hu/wiki/index.php?page=MembersPage%2FPhatBob%2FUserGuide
Could be well wrong here but may of had similar on my board ( no 5v for tps ).
.... populate R142 (270 ohm) and C69 (220 nF) which makes a current-limited supply
Please await for Rob to confirm.
Regards
Agriv8
regards
Agriv8
My map sensor was flipped upside down. :-\ Easy enough of a fix now It's working
I had strange behavior with TPS too...when i click "Get curent" it gives me always the diffrent value...when i kick full throttle and click get current it gives me 255 but when i set to 255 it doesnt come to 100%...?! I find values where on closed throtle shows 0-1% and on full 100%..any1 have a clue why is this happening?
I experienced this with calibrating the TPS.
I think it has something to do with zeroing the settings in memory. Input and upload the values 0 min and 255 max, then use the TPS calibration tool, it should bring back the correct values this time. Input, upload and check the operating range.
I think this also depends on firmware version as i dont recall it doing this on 1.0.53, though I may be wrong.
I never use the Wizards, just step up 10 at a time, then 5, 3, 2, 1 until you get the closed throttle one value below the point where it shows 1%. Then I do the same for WOT stepping down 10 at a time.
Quote from: [email protected] on October 29, 2007, 06:38:01 PM
I never use the Wizards, just step up 10 at a time, then 5, 3, 2, 1 until you get the closed throttle one value below the point where it shows 1%. Then I do the same for WOT stepping down 10 at a time.
I used that method after i saw that calibration is messy,its works thats importmant,i`m using 1.0.73 firmware