Ok I'm trying to get all the maintenance/repairs done on my 92 Ranger 4.0 with 102,000 miles. I posted earlier I had a fuel leak somewhere at the tank. I thought it would be the plastic retainer ring that Ford sold me because the same thing happened on my 98. But we checked it today and installed a new fuel pump but my 92 has a plastic tank but doesn't use the big plastic ring. Also the leak was caused by a cracked rubber fuel filler neck hose which I didn't think it was so I have to order it and redo everything all over again. However, my newest concern is spark plug arcing that you can see in the pitch black dark with the hood up, faintly looking down where the plugs and wires are all three on the driver's side and at least one on the passenger side. I thought yesterday it was only number 5 cylinder so I replaced the plug and wire but neither looked bad but it still does it anyway. I didn't use the cheap stuff either, I used Motorcraft original Copper plugs and Motorcraft wires. One of the plugs was loose but I know I tightened them all when I did the tune up not even 3,000 miles ago. I always recheck myself. What else would cause a visible spark arc that you can see and hear? It ticks so I know it's missing.

 

Usually, the arcing is caused by bad wires but since you've replaced them, I'm puzzled. Where is it arcing to? Did you use all the wire looms? I would try to separate the wire as far away as possible from anything that it can arc to.

Is the plug gap set correctly?

I don't know if I'd attribute the ticking to the missing. The injectors make a pretty good ticking sound and the arcing will make some noise as well. Also, the early 4.0 motors had some issues with soft rocker arms / poor lubrication and would develop some valve train noise due to the pushrod socket wearing.

 

Well I checked under the hood 2 nights ago and I could see a flash coming from the spark plugs on the driver's side and one spark plug on the passenger side. But I couldn't tell if it was coming from the spark plug or wire because it was dark and of course if you shine a light on it you won't be able to see. Anyway I had another problem on the way home yesterday the fuel pressure regulator was shooting out gas and flooding my engine, I almost didn't make it home. Luckily a mechanic I know stopped and helped and he got it replaced. I think it went ahead and fouled out the new plugs anyway. It smoked a few miles on the way home, has quit smoking, but still a slight miss when idling. So I did a fuel pump Wednesday and then Thursday the fuel pressure regulator blew out. It was actually rusted so bad on the outside probably from sitting up so long. So things are starting to show up now that it's being driven regular. The Low Oil Level light also came on when I drove it but the oil is not low and now the low oil level light doesn't even shine when I start up the truck and I just replaced the bulbs on the back of the dash and checked it before putting it all back together. Does it have a fuse? I don't have an owner's manual to check.

 

So I've never seen spark plugs do this or just never noticed it. I changed one side to Champion to see what would happen. It still glows at the plug to head every time it fired. I don't know if this normal or causing a slight miss. It does it on all but two cylinders. It looks like a spark plug tester glow that you can only see in the dark. Do I need to do anything?