944 only runs with ignition is in start position
 

I have an 83 944 NA that has a starting issue.

It's been sitting for several years. Ive done several thing to get it to this point.

Replaced fuel pump / fuel filter
replaced battery
replaced coil
replaced spark plugs
cleaned up, rebuilt and tested injectors
the reference sensors with oscilloscope at the DME connector tested good

now it starts up briefly then cuts out. If I keep the ignition in the start position it will run ok (I assume at risk of damaging the starter, so I dont do it for long, 15-20 secs), but it sounds good for that time. as soon as I release the key, it cuts back out.

I pulled the ignition out and a resistance check seems to be fine.

Also, I dont see any movement at the tack. I get a good signal from the reference sensors, so Im guessing that the tack may just no work.

Any suggestions welcome

Thank you,
Dave