Try a other cable see what happens,
Sounds like a noise problem, check ground and ground5 are connected right.
Happy new year and success
- I had similar problems on a BMW M30 turbo car with MSD dual coil ignition. Communication usually breaks when higher RPM and/or engine load occurs. I've used a long RS-232 cable to put the USB/RS232 converter electronics far away from high currents which helped somewhat but didn't cure the problem completely.
- Also check (and disable) the notebook's harddrive shock protection system if it has any. (GergelyLezsak?)
- try to run the notebook from battery (notebook not grounded to car-chassis, only via the RS232 DSUB9/pin5: the USB-RS232 cable and windows driver combination is usually less problematic this way)
- and from cigar-lighter supply (notebook grounded to chassis via supply and RS232: this is usually more problematic, but sometimes better)
- VemsTune supports TCP communication, so dependable parts can be used instead of the problematic direct USB-serial + windows driver.
- we are testing new wifi-serial and bluetooth-serial small modules (for wifi, big routers also work: OverTCPWireless but newer, small lightweight modules seem to work well too - unfortunately the prototype batch we manufactured was small, need to manufacture a bigger batch now).
Need help rs232 problem
A installer have made a BMW 325 turbo but have serious problems connection to vems.
Vems ecu nr. 4234
Web shop Bosch ignition coil 2x3
Web shop V3 harness 6 cyl
Rs232 Prolific rs232 cable also tested FTDI
- We have done:
Connected rs232 gnd to pin 17 ec 18. No luck
Removed ign. Coil from firewall to engine. No luck
Lowered ign. Dwell to 1 Ms. No luck.
Sometimes Vt is lacking but not disconnecting other times it´s disconnecting and they have to remove rs232 plug. Most times problem starts at 4000 rpm.
- I’ve made a Rally BMW using the same composes and funny part is that the car did have accurate same problems. Did not find a solution then but have to find the problems for 2012 rally season.
We will be happy if ANYONE has a solution for solving this problem.
Installers did firmware upload + config and all is fin now so case closed.
Tnx for helping
Making a BMW 325 turbo we did see the ign sliding up to 60 degrees (2000-9000 RPM).
- One test is made by using a "smart" strobelight but they can see exhaust manifold glowing red at 3000 rpm so the ign is moving (Vt is stable at ca 20 degrees)
Another bench test made by me using a scoop. Ch 1 measured the trigger 60-2 and ch 2 measured ign out. I see ign at 24 degrees after the missing tooth at 2000 rpm. At 9000 I see ign 36 degrees before the missing tooth. Vt is stable at ca. 20 degrees all the time.
Think I have seen this years ago but cant remember what cores that.
- measured how ?
- a smart strobelight can show similar symptoms (especially when fooled by wasted spark)
- or measured via scope ?
I did make a bench test and get the same results
Any idea how this can happen?
Log and config
- VemsTune validate
- Sometimes it's sg. very basic setting misconfigured that can cause this
- toothwidth = 6 deg ? reftooth 0,40,20 (from top to bottom) ?
- next trigger tooth = 20 ?
- nr of ign outputs, etc...
- definitely it is a good idea to try upload the correct configlet from bottom of "primary trigger dialog" and see if it helps
- i259 used for idle pwm, at 250hz, dual channel pwm IAC
- it worths a test with lower freq, or even disabled
- knock retard disabled ?
- although that would show up on VT gauge
- per cyl spark delay ?
please review these and reflect. We can review and benchtest the following working day.