1988 5.8 351 F250

With their truck running, does anyone else see a glowing blue corona effect on both sides of the ignition coil and spark plug wires when viewed in the dark? I looked under the hood last night because my my truck was acting like the wires were bad after only 1000 miles. I just replaced the coil but I was still getting poor acceleration/hesitation. The truck misses and lightly bucks most of the time except when I'm coasting so I think my wires went bad. I have a lifetime warranty on the wires so it's not that big a deal. Has anybody had wires go so fast and/or sees this phenomena.

 

If they r not quality wire even with lifetime they go quick . I run Ford racing now .

I will not name the other High end wires I used to run (lifetime warrenty) But every year they acted up . Take em back get new ones and keep track of how long last. All u r out is your time to put them (make u have) on as they r free. Good luck

 

Yeah. Are they Motorcraft wires with a lifetime warranty? (Never heard of such). If they're MSD wires, they make good tie-downs, otherwise, they're worthless on a Ford. I put MSD's on mine, and in less than 5K, they lit up my engine bay like a Christmas tree. Same goes for SOOPER DOOPER platinum plugs. Wires (MSD) and plugs (Bosch Platinum II's) BOTH went out in less than 5K. Put the Motorcraft stuff back in it, and BINGO, no more ping, miss, or pre-detonation. Besides that, the Motorcraft stuff was cheaper than the MSD. Did you put a Motorcraft coil back on it. I've heard good and bad about MSD coils. I'm still neutral in that department. But, make sure NOTHING is anywhere near that coil, including rubber hoses. My brake booster hose got down on my original coil, and the coil arced out the side to the hose. If I hadn't seen it with my own eyes, I wouldn't have believed it would arc to something rubber. The coil eventually went to that great coil place in the sky, but I put an OE replacement coil on it.

The voltage on the secondary of that coil is EXTREMELY high voltage (something like 50KV comes to mind). Remember, you're trying to get electricity to jump an air gap at the dizzy and at each spark plug. Air is NOT a good conductor. Those circuits MUST have good insulation to make sure the energy for the spark is delivered to where it's supposed to be. If the impedance of your wires/plugs is too high, it could cause elevated voltage at the coil as well, thus, the corona. You WILL eventually kill the coil if it's corona you can see. Corona will cause a degradation of the insulation in the coil. Get some good Motorcraft 8mm or 9mm wires, the plugs recommended on the sticker under the hood, and gapped right (also on the sticker). Your ignition woes will go away.

 

Thanks,

I had the corona effect with the original Motorcraft coil (186,000 miles) before I changed it. Thought it must have been going because of the blue glow I saw. The old wires showed about 2.34 K resistance per 12". The resistance on every wire was about the same per foot. Is this right? Even if the resistance is not out of spec. the blue tracer lights I saw randomly shooting along the wires can't be good!

The metal heat sink of the coil is screwed to a metal bracket which is in turn bolted to the metal valve cover. This has to be the best ground in the world. I can't imagine the high voltage will have any problem arcing if it wants to.

Does anyone have the correct spark plug wire routing for the 5.8 351? I know that #5 & 6 cylinders fire sequentially and I got to keep those two separated but I don't know the recommended routing