This is frustrating I've been just throwing parts at this thing the past year . I guess I can take the plugs out and recheck the gaps . What else could cause this ? I'm truly at a loss . Is there a plug part # you guys would recommend ? The ones in there now are from Ford ?

 

When all else fails (tho better to do this first) with electrical issues, try cleaning up the electrical connections and ground points. It doesn't cost a dime and won't hurt a thing. You mentioned the exhaust manifold leaking. Are the boots getting roasted?

 

I will check the connections and grounds tonight . Is there any particular grounds I should focus on ? The boots look fine no burns or scorching , Though one did have a bit of soot ? Thanks guys I'll keep trying .

 

I mean are the boots getting melty from the manifold leak?

 

No not that I can tell . They look pretty good . The ceramic part of the plug that's not covered by the boots are a bit tanned . I took the ignition system apart and cleaned all the connections , rechecked the gaps and firing order , re routed the wires to lessen the chance of cross fire and checked and cleaned up the ground wires . Fired it up and nothing's changed . From searching I keep hearing that running lean can cause this though I don't know how ?

 

Lean mixtures are tougher to ignite. How do the plugs look, running lean?

 

Some good points here.

Check your spark plug gaps to make sure they're not too wide.

After installing the plugs, spray them down with some brake cleaner to strip off any dirt or oil.

Wipe the plug wire rubber boots clean and then use a light smear of silicone grease inside each boot. They sell little packs of the grease for $1 at the auto parts store, or maybe you have some for plumbing already.

I don't think carbon deposits from the leaking exhaust are likely to be the cause. The boots should cover enough of the insulator to keep it clean and prevent arcing.

Good luck!

 

I'm wondering if perhaps he has too MUCH dielectric grease- and it is contacting the center contact, & providing a path... Dielectric properties allow it to conduct electricity: IF it is overloaded, maybe that is allowing the spark to travel- if it not a wire issue...

Wipe them dry, and apply IAW the instructions in this link: 1983 Ford Bronco TSBs & FSAs (Recalls) for '83-96 Broncos & F150s picture | SuperMotors.net

It does state NOT to get any on the center conductor...

Scott

 

They also sell really big tubes for about $2.50 (or maybe it's $4.99, I'm just guessing). Regardless, it's a WAY better deal then the "single-use" packets.

 

Ahhh ok I just put a small dab in the boot hole and used a pencil to smear it around .. I will take them out again and clean them up and see if that helps . Is there a chemical I can use to get any excess silicone off from inside the boot

 

Silicone is a b1tc4 to clean off (as in getting completely free of it). There are very few chemicals that will get rid of it - that's why it's such a stable material chemically; acetone, gas, ammonia, almost nothing dissolves or reacts with it. I think you can use sodium hydroxide (lye) mixed with hydrogen peroxide, but that would eat the rubber boots!

You should be fine just wiping with some paper towels. What you don't want is any going up into the metal clip area, but even that would not be a disaster - just use a Q-tip to wipe it out.

Just use your pinky finger to smear a thin film around the end where the rubber seals to the body of the plug.



For what it's worth, LOTS of old engines used spark plugs where the high tension wires attached with screws and metal was completely exposed - no rubber boots covering them.

 

I'm guilty of getting off into the brush trying to troubleshoot remotely too - but let's back up a bit.

Three different sets of wires - same problem, something else is the culprit. A dab of dielectric about the size of a pea is about right, but it's not going to be an issue?

The high tension voltage will always find the path of least resistance. The idea of course is to make the spark plug gap that path. Too wide a spark plug gap would do it, or the wrong plugs, fouled out, worn out. Or too lean of a mixture.

 

I will clean the boots and stuff . But I'm betting it's a lean condition or something . It's hard to diagnose without any codes appearing . And if my exhaust manifold leak is the culprit you'd think the computer would fatten the mixture due to the O2 sensor reading lean ? I just replaced my fpr to see if that would help . Maybe I have a vacuum leak ? I'll check it out and see what I can find . I know my egr has been on my mind this whole time but not sure why lol

 

I checked the gaps btw and they were all at .44 , the plugs are new from Ford . The plugs I had in there before were only a few months old and they were autolite 26's

 

Kind of with Tedster here. Need to back up.

NGK wires are top flight in my book. Have used them on many motorcycle and car engines with never a peep. Can't believe there's any problem with the new MSD wires either. Even the old ones were probably ok, but maybe too high a resistance to provide a hot spark.

The new Motorcraft plugs were probably gapped acceptably from the factory. That's modern manufacturing for you.

Here's an idea: Wait till dark, start that engine, then film it with your cell phone and post it for us to see.