Carrera 4 need wiring info

[Fredh]

Hi,
Last December the car cut out and failed to restart. investigation isolated the problem to either an intermittent connection between the main relay board and the DME computer or a possible problem with the computer. No fault was found, but after "playing"with the relay board and disconnecting/ reconnecting the computer the car started and until today has perfomed perfectly.
It's done it again! This time in my garage not on the open road. I know that pin 85b at the DME relay goes to pin 3 on the computer, it chects out ok. Can anyone tell me to which pin on the computer pin 87 goes?

I changed the DME relay last December. I have power to the computer, the engine turns over easily and I can smell fuel.

Assuming the wiring checks out ok is it possible to get the computer checked?

Thanks in anticipation

Fred

 

[Dave Wilkinson]

Fred,

It looks like pin 87 on the relay goes to pin 37 on the DME. It looks like that could be a main power supply because it splits after the relay and goes all over the place, including to pin 37 on the DME.

A common problem which gives your symptom is the failure of the engine speed sensor on the flywheel. If it doesn't see the engine turning at >30rpm it won't let the DME fire the ignition.

Hope that helps.

Regards


Dave

 

[Fredh]

Dave,

Thanks for the info, I will check to see if I have continuity. Is there an easy way to check the speed sensor is functional?

Thanks again for your help.

Fred