914 2.0 refuses to start Options

[Frank Lolkema]

I have a problem with my ´73 2.0 with the original fuel injection that drives me crazy!
I have completely overhauled the engine. After putting it back in I can not get it to start with the starter motor. The motor crancks but it will not start. When I pull it with another car it will start instantly. Using jumper cables from a car that is running at 3500 rpm does not help. Here is what I have done so far:

Replaced the battery with a new one;
Checked all the wires and connections, everything is set up correctly and the connectors are all oke, I´ve used contactspray on all contacts;
Replaced the spark plugs with new ones, left the new ones in, put the old ones in the caps and crancked the engine, all spark plugs give a good fat spark;
Set the timing;
Replaced the starter motor with a different one;
Checked the ground strap from the gearbox the the chassis;
Attached a starter cable from the gearbox directly onto the negative lead off the battery to elimanate ground strap problems;
Checked the fuel injectors, they all inject fuel when the enige is crancked;
Put in fresh new fuel;
Airfilter is new;

I really don´t know what else to try. When the engine runs, it runs perfectly, very strong, no smoke, no misfires, no strange noises. When I switch it of warm it also refuses to be started in the conventional way. I really don´t know what else to look for, it drives me crazy! (IMG:style_emoticons/default/headbang.gif)

Anybody have an idea of what I can/should look for?

Frank