91 e.g. 1500 dual carb civic will stall on idle most times and idles like its on 3 cylinders will run fine till get up to 5000 rpm then will lurch and cough

It happened after I jump started a friends car while jumpstarting it died will start fine just won't hold low revs

I would remove, clean (Stoddard fluid) and rebuild the carburetor. Not a bad job on Japanese carburetors, since they love to use O-rings rather than gaskets.

Also its getting error code 5 from the ecu I don't think it is the carbys because was fine until an arc from the jumper cable to the air filter cover cut it out whilst I was jump starting ever since then runs rough

Code 5 = Manifold Absolute Pressure (MAP) Sensor

MAP Sensors can be very expensive. As you found out, it's not safe to jump start modern-day cars, since voltage spikes can destroy ECMs, alternators, and sensors. It's safest to remove and fully charge batteries.

Okay we found the problem would never have guessed it for myself after the mechanic took a day to diagnose the problem it ended up being an earth cable from the carburettors they need to be earthed hope this helps someone else

Nice job. I'll have to remember that. Is that because of the Throttle Position Sensor?