Try a other cable see what happens,

Sounds like a noise problem, check ground and ground5 are connected right.

Happy new year and success


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

Add a capacitor to ign. Coil. No luck

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 its disconnecting and they have to remove rs232 plug. Most times problem starts at 4000 rpm.

We will be happy if ANYONE has a solution for solving this problem.

Thank you


Ignition problems:

  • Status.

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.

Any clue?

Vt is stable at ca. 20 degrees and no trigger errors.

I did make a bench test and get the same results

Any idea how this can happen?

Log and config

short quicklist

please review these and reflect. We can review and benchtest the following working day.