1999 s80 2.9 won’t start, has fuel has spark and it will crank but won’t start, the rpm will spike high when trying to start and before when it would start when I tried to start it and wouldn’t turn over so the engine would be off but the starter would click like it does when you try and start it when it’s running but it’d do this with engine not running but then it’d start next try. The injectors pulse was not the same across all 6 when I pulled them out. Any ideas thanks!

 

I'd advise looking into the fuel system, like the fuel pump, filter, and pressure regulator. There might be a blockage or pressure problem causing the uneven fuel supply.
Also, check the timing parts, such as the belt or chain, for wear or alignment issues.
And I’d check for anything that maybe blocking the air intake system.
Have you checked for error codes or run a diagnostic scan yet?