I have 95 Topkick 366 I use as a water truck and to haul sand from my neighbors for my MX track. Last year it was missing under load and I noticed some of the plug wires were burnt and missing half the boot on the plug. I'm getting ready to haul some more sand so I replaced the plugs and put all new GM plug wires on. I had it running decent with the new wires and old plugs but today when I put the new plugs in, it didn't want to start and when it finally did it was barely running and pumping way too much fuel (it is fuel injected). It had the check engine light come on. I took the air filter out which was pretty dirty and then it started and cleared up and was running really good. I put the air filter back on and now it seems to be good again. I didn't drive it anywhere but it seemed really odd. Could the new plugs have affected the computer and it just needed to reset itself? I don't know much about how fuel injection systems work but apparently this is an earlier version and not as complicated as ones today. I'm hoping I just have to get a new air filter and use it and see what happens carrying a load. Any input is appreciated.
It will be very complicated if it stops runing. I think the plugs could have made the computer act up.I have worked on some of these and they did unexplaned things from time to time. I hate computers on engines.
I was working on a porch pick up change the plugs I had the battery disconnected and when I went to started it ran extremely rough talk to the Ford dealer they said that's common as it has to relearn after disconnecting the battery. I agree somethings just don't need a computer on them