Good morning sir.
I'm watching your videos for a longer time, now I decide to subscribe. I have a 31,000 miles Grand Prix from 1991. I spent over $2,000 because sometime seems like it's running in five cylinders. nothing fixed this car. can you tell me again what kind of cleaner should I purchase for injectors?
Thank you
Scotty has generally recommended the ATS Carbon Clean fuel system cleaner, and PEA-based cleaners such as Techron and Gumout.
However many things can cause engine misfires. You have not detailed what diagnostic steps have been taken so far, but for something that old I'd probably start by checking engine condition with a compression and/or leakdown test, then work outwards from there to check the fuel and ignition systems. You could also check for any OBD1 codes.
