P0300 random misfire. i installed the lower intake gasket and got a p1345 timing off. I brought it to the shop to set the cam retard with a scanner. Now I'm getting the random misfire p0300. 1,3,4,8, are getting fuel to the injectors. They are firing but when I disconnect it doesn't make a difference to the rough idle. What would cause all four injectors to stop getting fuel. Electrical? How can I find it/fix it? Or maybe something with the spider injector not working. I was going the take the upper I take cover off the inspect the injectors. Any ideas?

 

I was able to diagnose by finding www.easyautodiagnotics.com the spark was at all 8 plugs and distributor cap. The whole spider fuel injector was shot mainly the fuel pressure regulator. I found out the fuel pressure regulator goes out often in these trucks. It was all charred black I replaced the assembly with the mti conversion kit and it fired up without any hesitation.

 

Thanks for reporting back your solution. Makes the forum work as it seems to be a common problem and will help someone else in the future.