Ive been having problems with my S1 to the point i stopped using it and bought a Datsun S13 instead. Ive still got the S1 though and fully intend to get it back on the road.

There was a severe running problem where it would just splutter and die when under load but as soon as you take it out of gear it runs and revs fine.

Ive changed the fuel pump, the coil, the dizzy cap and rotor and the plugs so far. I know the leads are good and the injectors are fairly recent. The metering unit seems to be doing the job aswell.

Now all i can think of are the AMAL valve or the ECU. Im leaving the ECU as a last resort as the car currently has a good chip and i dont want to be disturbing it.

I recently looked at the AMAL valve only to find theres a pipe missing. There is the outlets, one going to the Wastegate, one going to the turbo somewhere but the other, the middle i think, is bare. Im not sure if it should go to the Air filter or ECU or something else? I currently have a cone filter on the car.

I can take pictures if needs be.

Your help is greatly appreciated and will get my interest right back up with this car instead of my wanting to sell it!