So yesterday went to work no problems. Had an appointment after work, drove there with no problems go to leave and truck starts fine but missing. Got it home on 3 cylinders. checked the spark plug wires and found the fourth all corroded at the plug and when I went to pull #1 the tip of the cable broke right off. So I went and got some new wires and it was running fine. Drove to work this morning no problems, came home no problems, go to the store no problems, go to come home and it starts misfiring again. I check for a spark from each wire and each wire is good so the distributor cap and rotor must be fine. I'm just about to ride my bike down to the store and I'm hoping that maybe it's just a failing spark plug and not something worse but does anyone have any idea what could cause this? There are a lot of miles on the engine and it hasn't ever been rebuilt or had a new head gasket put on. Could bad compression be intermittent? Or could it be a clogged or bad injector? I can't figure out what would cause it to be intermittent other than a short or a bad plug wire but it shows fine up to the plug.

 

replaced the plugs, started it, no miss. took it to the store, drove fine. left the store back to misfiring again. A not so trustworthy guy I talked to while I was out said it could be the timing. I did have some issues with timing a while ago and I set it by ear so could that be it? anyone?

 

 

I just decided to go out and see if it was still misfiring now that the trucks cooled down and it started up with no misfire. I guess it could be running to rich. I have noticed that there seems to be a lot more heat than usual coming from the exhaust manifold. I don't have a timing gun but I'll probably take it in. The valves could use adjusting too so I might as well get that done at the same time. The issue I had with timing earlier was from replacing the seals on the timing cover.