Hello

we are converting a 911 from 2.7 to a 3.2
when we try to start the engine turns but we have no gound to the ignition coil only 12v to the black cabel (is it sopposed to be ground on the green cabel)
we have checked the rpm sensor and tdc sensor and the grounds and 12v on the dme connecktor
do someone know what to check more thanks
i try to help my 911 friend to get it started

sorry for bad english too many bears

Fuel pump relay.
Ground within the ignition circuit on the DME is for the coil.
Bad solder joints in that board may make it not work.

Rich

Thanks for your fast answer
The fuelpump is running
the problem is no 12volts on the ignition coil
we have gone through this list but everything is looking ok

http://forums.pelicanparts.com/porsche-911...y-resolved.html

this is the 911 we are working on

Click to view attachment

Fuel pump relay controls ignition also.

The dme may also have a loose connection on the solder of the joints.
That is where you get your ground to the coil from, the dme.

Rich

reference sensors on the flywheel. Check the harness going to them and ohm them out. Specs are somewhere on the interweb

One other issue with them is they actually can be out of adjustment ( depth )

http://www.youtube.com/watch?v=zeFOOcLSk60

The video is great. If it ohms too high get new sensors. You can use bmw sensors instead of porsche sensors. Same thing but the bmw has a bit longer wire attached to them. They are cheaper.
Check distance to tdc "bolt" on flywheel to sensor. Make sure that distance is correct. If the distance is too small you can chop off the bolt head. (ask me how I know.)

I assume you are not getting spark? Do you smell fuel? Usually you try the dme relay first and then you make sure you are getting the fuel pump to run. Last year on my 3.2 914 I couldn't get the car to fire up. The mechanic said the sensors were fine. But then I checked at the wiring harness like the video and the ref sensor ohm reading just kept on going up up up. Replaced both sensors (bought the bmw version sensors from pelican) and started right up until we heard a bad screech. Then it wouldn't fire again. That how I found out about the sensor distance to the flywheel sensor bolt.

I even bought another 3.2 ecu to see if the brain was bad. That was before I went back and checked the sensors at the wiring harness at the ecu.

Buck