MoTeC Global Forum

Hi guys,

I have a M880 which has been running on a Opel/Vauxhall C20XE. It has formerly been running with crank and camshaft sensors, but now a cheaper engine solutions has been made. It is only running with a crank sensor, and it is now going to be running wasted spark instead of 4 COP. When i look at the MoTec drawing called M37 which is a 4 channel Bosch module, I get a bit confused because the drawing wants me to connect cylinder 1 and 3, and 2 and 4 together. Other aplications i used to work with has always been 1-4 and 2-3.

How about in the ECU setup, how do i tell the ecu that it should not be looking for the sync signal anymore?

Thanks in advance,

Best regards

Mads

Hi Mads,
I would not use the four channel module in waste spark, I have had experienced where the modules do not like this. I would use 2x two channel modules and make sure you wire it so the two channels on one module are not being fired at the same time.

You can tell the ECU that it just has two coils now and you will have two outputs each wired to two module channels.

To use just a crank signal you will have to run the engine as group fire. For a four cylinder you need to tell the ECU that the number of cylinders is "24" this is a special mode which will use four injector outputs but fire them in a group fire arrangment.

As for ref/sync mode you will have to use a synced once per rev mode like 36-2 on the crank. What crank trigger do you have?

Not sure why you would ever go from sequential back to group fire...?

Hi Mark,

Thank you for your reply.

The reason why it is going back to a non sequintial mode is because the engine which used to be in the car is a highly reconstructed engnine build for WTCC, and know a much cheaoer solution is going to be made for endurance racing. The normal Opel engine does not have a camshaft sensor.

It is running 60-2, which as i understand isnt a problem.

I will take your point regarding modules seriously and rewire it.

Best regards

Hi

The C20XE engine in Opel Vectra A and Astra F has a cam position sensor on the exhaust cam.
If you use that you can run the engine sequential.

Arve Flaat

Hi Arve,

Thanks for your information, I will look into adapting one in the future, for now it must be done with the crank alone:)

Do you happens to know the CRIP for the c20xe engine, I have measured it like this:

Cyl 1 at TDC, turn the engine in it running direction, until the index tooth(First tooth after tooth gap) is aligned with the sensor. I got 245 degreees, so that minus 720 is 475. I just dont think it is right, the engine startet, but not very good. If I alter the overall ignition trim it doesnt make things better. Unfortunately I didnt had more time last night to try other settings, but if you could tell me that I am way off, no reason to spend time:)

Thanks in advance

From a Webinar I think:

Hi

Normally the CRIP on a C20XE is 60.
Disconnect all the injectors.
Set the ign table on low RMP to 0
Attach a ignition lamp in ign 1.
Crank the engine.
If it is right you hit 0 on the engine marks.
If it not is on 0, adjust the CRIP so you hit exact at 0.


AF

Thank you very much for your response, I will try it out when I get back in the workshop.

Mads

Also remeber that going from a 720 degree cycle to a 360 degree cycle will mean that the original fuel map is probably way too big. The injecotrs are now firing twice as often.

Thanks for your comment, It turned out that the fuel map had to be massively reduced. But it went well ,and engine is now running smoothly.

Thank you all for your help and advice.