Fuel Injection/electrical issue

[abo1010]

Hello

I have Fiat 1981. The problem is car start and dies after 2 sec. I did a lot of trouble shooting tests already. Also tried another ECU. But I found a lot of people dealing with same problem. Car starts on cold valve and Fuel don't pass 4 injectors. They are not firing.

One more thing if I hold key in "cranking" position it works.

The "cranking" position picks up the relay fuel pump relay via a different path than the "on" position of the ignition switch. The car will start on the cold start relay and run as long as i keep cranking but die shortly after i release the key.

Seems like I have bad ground somewhere. If anybody knows something that can help, and where to look. Please advice. Thank you!

[spider2081]

One more thing if I hold key in "cranking" position it works.

If you have a fuel pressure gauge I would check it. The fuel pump switch in the air flow meter is bypassed when the ignition key is in the "start" position. If the AFM fuel pump switch is defective the fuel pump will only run when the ignition key is in the 'start" position. when the Key returns to the "run" position the engine will continue to run until the fuel pressure drops below around 20 lbs. This can take a few seconds and can easily be confused with the engine running off the cold start valve only. The fact the engine runs as long as the key is in the "start" position makes me wonder if the fuel pump switch in the AFM is not working properly.
On my 81 Spider I can remove the hose from the plenum to the AFM, turn the key to the "run" position and then move the flap in the airflow meter. The fuel pump relay "click" can be heard while doing this from the engine compartment. If you have a fuel pressure gauge connected at the cold start valve it will indicate about 30 psi.
Hope this is some help

[abo1010]

I have fuel pressure 36 psi if I move AFM flap. And 30psi when car starts and it's not dropping less. Also fuel pump works as I move flap in AFM. I don't know where to look else...

[spider2081]

That all sounds good.
I would next check the connections on the coil. The + side of the coil should have a "pink" wire connected to it. This wire is switched power from the ignition switch. The negative side of the coil should have 2 wires on it. One brown/white wire for the tachometer and one more wire could brown/white for the fuel injection. The second wire could also be a shielded wire sometimes yellow covered with a black sleeve.