[Diy_efi] Bosch DME trouble...

[Richard Wakeling]

Hi Mike,

Mike Sharp wrote:

> Hi,
>
> In case you missed my last email...
>
> Porsche 924S, Bosch L-Jetronic w/Lamba control, Motronic
> The car starts and runs reliably (its drivable) for the 15-20 seconds it
> takes to switch from
> cold-start to warm-up mode.
>
> Per the Porsche shop manual:
>   . grounding all around the system has been verified
>   . Power to the DME control unit is correct
>   . Fuel pump runs
>   . The speed and reference mark transmitters have been verified via
> 'scope and have sufficient signal strength
>   . Temperature sensors I & II have been verified via resistance checks
>   . The throttle switches (both throttle closed & wide open switches) are OK
>
> What does look out of spec are the voltage readings on the air flow
> sensor.  The shop manual says >8V across pins 9 & 6 (with the flow
> sensor & motronic connected) on the Motronic.  I've got 5.5V.  I swapped
> out both the flow sensor and the computer for other good units and the
> resutls are the same.  I verified that the harness between the Motronic
> and the air flow sensor aren't shorted or corroded.  With the hardness
> disconnected at both the airflow sensor and the Motronic the resistance
> plug-to-plug is minimal (a couple of ohms) and resistance between pins
> is infinite so I can't account for the voltage difference relative to
> what the shop manual says.
>
> So what am I missing?

A Delco ECM

Sorry

Cheers Richard
Dicks Electronics
http://www.dickselectronics.cjb.net

>
>
>     --Mike
>


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