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Recent posts
#41
Fuel Injection / Strange stuttering while drivi...
Last post by pikard - August 14, 2023, 05:05:09 PMHello guys,
I have a strange problem with my car. It happens almost at about 1600 rpm. While I am just trying to hold the speed the car starts to stutter.
You can download the log file here:
https://drive.google.com/file/d/1mHYLDcOw64xJjy0TpWk3nRLlYwGn2b58/view?usp=drive_link
And here a screenshot:
https://drive.google.com/file/d/1gw9qg_QE2SZAefa6RoIqwCa2v-ELJoLI/view?usp=drive_link
The vems data:
Creator=VemsTune 1.5.57 (2018-01-04)
Version=1.2.38
SerialNumber=v3.3_u022515
First I disabled the EGO correction but it does not solve it.
Next try was to disable the fuel cut and resume but nothing.
After that I played with the MAP filter in the ECU calibration but I had no improvement.
It happens in the 1600 rpm area only. Everything above is fine.
Sometimes it helps to turn the ignition off and on and the car runs fine.
Any ideas?
Thanks in advance
Marcus
I have a strange problem with my car. It happens almost at about 1600 rpm. While I am just trying to hold the speed the car starts to stutter.
You can download the log file here:
https://drive.google.com/file/d/1mHYLDcOw64xJjy0TpWk3nRLlYwGn2b58/view?usp=drive_link
And here a screenshot:
https://drive.google.com/file/d/1gw9qg_QE2SZAefa6RoIqwCa2v-ELJoLI/view?usp=drive_link
The vems data:
Creator=VemsTune 1.5.57 (2018-01-04)
Version=1.2.38
SerialNumber=v3.3_u022515
First I disabled the EGO correction but it does not solve it.
Next try was to disable the fuel cut and resume but nothing.
After that I played with the MAP filter in the ECU calibration but I had no improvement.
It happens in the 1600 rpm area only. Everything above is fine.
Sometimes it helps to turn the ignition off and on and the car runs fine.
Any ideas?
Thanks in advance
Marcus
#42
Modifications and Repairs / Flex Fuel
Last post by Pork Chops - August 03, 2023, 08:49:44 AMHi Guys, I've got an VEMS ECU running a home turbo charged Porsche 3.2 Carrera. It's been built and tuned and runs well. I'm preparing the car for a flex fuel (E85) set up and have modified the fuel system exhaust and intercooler and can't wait to get back to the dyno.
I'm hoping someone can assist with the physical side of getting the flex fuel set up. The ethanol sensor is plumbed into the fuel system, the plug is pinned at the sensor and I've got signal, power and gound wires to the EC18 plug and have the correct female pins and seals. I've been told the sensor ground goes to pin 17, but I need to establish where power is coming from, and lastly I need to get a wire from Wheel speed sensor 2 (which is on the board) to a free pin. Can anyone assist in identifying where this is on the board?
I realise some of these questions may relate to the pinout used in this application but perhaps there is another Porsche PNP user out there that's done this before?
Many thanks.
I'm hoping someone can assist with the physical side of getting the flex fuel set up. The ethanol sensor is plumbed into the fuel system, the plug is pinned at the sensor and I've got signal, power and gound wires to the EC18 plug and have the correct female pins and seals. I've been told the sensor ground goes to pin 17, but I need to establish where power is coming from, and lastly I need to get a wire from Wheel speed sensor 2 (which is on the board) to a free pin. Can anyone assist in identifying where this is on the board?
I realise some of these questions may relate to the pinout used in this application but perhaps there is another Porsche PNP user out there that's done this before?
Many thanks.
#43
Ignition / Re: enabling camsync makes ign...
Last post by Machismo - June 22, 2023, 10:55:49 AMHere is the firing order, I mean it sure is strange, why on earth would Vems with cam-sync want to stop in the middle of the firing order list and have a break? It makes me think this is some software bug.
Here are the secondary trigger settings, let me know if something is not right
Here are the secondary trigger settings, let me know if something is not right
#44
Ignition / enabling camsync makes ignitio...
Last post by Machismo - June 22, 2023, 12:48:01 AMI had a single coil with a distributor which worked perfect and now I converted it to sequential ignition.
Meaning I have 8 coils which are controlled by eight +5V logic outputs. But to do that, the camsync needs to be enabled, for which I added a secondary hall trigger that is in a dummy distributor.
The engine is a even fire V8 so there is a steady flow of sparks to each cylinder. My primary trigger is 60-2 on the crankshaft which has worked very well. And when I take a trigger log when using a starter to rotate the engine it looks like this.
but with the camsync enabled, vems decides to first give spark to first four cylinders like it should, then it pauses for some unknown reason, and then (too late) it activates the ignition to the rest of the four cylinders. and then after that another pause. So basically the engine runs only 1/4 of the time. Why is this happening? As you see there are no green lines at all for a period of one crank rotation, so every second rotation there is no spark at all.
3.6 board
firmware 1.2.44
config 1.2.42
Meaning I have 8 coils which are controlled by eight +5V logic outputs. But to do that, the camsync needs to be enabled, for which I added a secondary hall trigger that is in a dummy distributor.
The engine is a even fire V8 so there is a steady flow of sparks to each cylinder. My primary trigger is 60-2 on the crankshaft which has worked very well. And when I take a trigger log when using a starter to rotate the engine it looks like this.
but with the camsync enabled, vems decides to first give spark to first four cylinders like it should, then it pauses for some unknown reason, and then (too late) it activates the ignition to the rest of the four cylinders. and then after that another pause. So basically the engine runs only 1/4 of the time. Why is this happening? As you see there are no green lines at all for a period of one crank rotation, so every second rotation there is no spark at all.
3.6 board
firmware 1.2.44
config 1.2.42
#45
Projects & Installs / Re: Porsche 928
Last post by Joc - November 03, 2022, 11:13:31 PMwhat is the use of the IF wire on the vems module
#46
Software / Re: WOT - shift cut time set t...
Last post by Morty - October 03, 2022, 05:41:20 PMI have the same issue on firmware 1.2.38. Which firmware version should I go for. A local VEMS dealer updated to this and said it was the one he recommended.
#47
Configuration / Re: Shift cut, fixed ignition ...
Last post by Morty - August 15, 2022, 02:12:49 PMFound the setting in the menu for Ignition setup. There was a setting not allowing the ignition to go lower/later then 0. I adjusted it to -20 and now it works.
#48
Configuration / Shift cut, fixed ignition Fw 1...
Last post by Morty - August 15, 2022, 10:26:57 AMI’m trying to setup my shift cut and when setting the fixed ignition to 20˚ ATDC, the ignition goes to 0,5˚ ATDC when shift cut is active, same if I set it to a higher degree ATDC. If I set it to 0˚, it goes to 0˚.
Is there a setting elsewhere affecting this or there is a bug in the software? Anyone who knows?
Is there a setting elsewhere affecting this or there is a bug in the software? Anyone who knows?
#49
Wiring & Sensors / Re: TPS 5V Dropping after 15-2...
Last post by jrussell - August 12, 2022, 05:59:20 PMHad some good discussion on this in the VEMS Users Group facebook group, but summarizing here for history/search purposes.
Pin 29 is a voltage divider. It shouldn't drop voltage unless there's a significant current draw on it. Is the TPS the only device on pin 29?
Does pin 28 (a 5v voltage regulator, not voltage divider) exhibit the same? Are there devices on pin28 now? If not, you could use that to see if the behavior follows.
I have seen where a bad (non-compliant) USB to serial cable pulled pin9 low on the db9 port... after 5-15 minutes. This is used for 5v power for the bluetooth devices and is standard in the rs232 spec. This is verified to not be the case in this instance, but just pointing out the possibility.
Pin 29 is a voltage divider. It shouldn't drop voltage unless there's a significant current draw on it. Is the TPS the only device on pin 29?
Does pin 28 (a 5v voltage regulator, not voltage divider) exhibit the same? Are there devices on pin28 now? If not, you could use that to see if the behavior follows.
I have seen where a bad (non-compliant) USB to serial cable pulled pin9 low on the db9 port... after 5-15 minutes. This is used for 5v power for the bluetooth devices and is standard in the rs232 spec. This is verified to not be the case in this instance, but just pointing out the possibility.
#50
Wiring & Sensors / TPS 5V Dropping after 15-20min...
Last post by Mikkson99 - August 11, 2022, 07:37:22 PMHi. I've got a m50 turbo, with VEMS v3.
I got a problem; After 15-20 minutes the TPS 5V supply will drop to around 2.6-2.7v and the ECU don't get the rigt readings.
Happens every time. Taught it may be the low voltage, when I didn't hav an alternator yet, but that did not help. Testet latest today, with 14.v on the system.
Measured same voltage both at TPS connector and EC36/29, so I guess the wire is fine. Also measured the wire end to end, 0.7ohm, and to ground - OL...
Also I was suspicious that the TPS itself where bad, as it was a "UAES" china copy thing. Got hold of an OEM BOSCH, but that didn't help neither.
Does anybody have a clue at what is happening/wrong?
Best Regards /Sondre Mikkelsen
I got a problem; After 15-20 minutes the TPS 5V supply will drop to around 2.6-2.7v and the ECU don't get the rigt readings.
Happens every time. Taught it may be the low voltage, when I didn't hav an alternator yet, but that did not help. Testet latest today, with 14.v on the system.
Measured same voltage both at TPS connector and EC36/29, so I guess the wire is fine. Also measured the wire end to end, 0.7ohm, and to ground - OL...
Also I was suspicious that the TPS itself where bad, as it was a "UAES" china copy thing. Got hold of an OEM BOSCH, but that didn't help neither.
Does anybody have a clue at what is happening/wrong?
Best Regards /Sondre Mikkelsen