Hey, for those that run Dan's suggested ZFR 5N plugs (I am trying them for the 1st time) does the longer extension of the firing tip promote pinging? I know that I have to chk out my distributor advance anyways, because my truck pings at odd times; empty, overnite cold, 2 blocks from home, did not allow it to sit/warm up, outside temp high 30's and it was pinging. seems like same conditions warmed up it (usually) don't. but it does under other unlikely conditions. I'm wondering about weak or busted/missing advance springs letting the adv weights do as they wish w/o any "control"; it does spin over REAL easy/fast with what looks like couldbe the starter it left the assembly like with 25 yers ago; its the longer housing'd one (rebuilders call it a 3258) as opposed to the whiney old 3257 standby); it spins over so easy it's like someone yanked a plug or 2! Yet it runs decent with OK power (considering it is a 3/4 ton P/U) going down the road; only other mod is an MSD-5-C ign control box; I put the ZFR plugs in it before I even drove it the very 1st time; so I don't know what it did (ping wise) with the Champion RN 12YCs it had in it. It did ping a bit, towing my Cherokee uphill in Wisconsin, on the maiden voyage home. And upon getting it home I R&R'd the carb and cut off the seal plugs blocking access to the mixture screws and wound richening the mixture ~3/4-1 turn on both screws, for optimum vacuum and RPM. (holley BBD wannabe, no feedback)

no, they help with pinging/detonation by bringing the spark kernel further out into the chamber, this reduces the amount the flame front has to travel. read the plugs to determine whether this is a mixture problem or a timing problem and go from there.

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I've been calling it as i see it for my entire life and that's not about to change. Take it or leave it.

Step's got good info. Also keep in mind the ZFR5Ns are of the ordinary slant-6 heat range; if you're going from a significantly colder plug and your overall setup was configured for that colder plug, then the standard heat range of the ZFR5N might bring about some ping.

You did remove the metal ring washers from the plugs, right?

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

If you tailored your spark advance based on the original type of plug and set an aggressive advance, changing the start of the flame front is a bit like putting a few more degrees of advance in... which in some cases (more compression, aggressive advance curve) can cause pinging... for a 'stock' or close to stock setup they are great... if you have done a fair bit of modification... well... time to re-dail the curve in...

So does it ping when you are under load and you have fuel spread all over the mix and low vaccuum? (highway/half throttle/hauling a heavy rig)

-D.idiot

that's fair.

as to context of the OP, the answers are already there...

i really dont think the plugs caused this condition. random pinging suggests dodgy fuel quality... an advance can diaphragm starting to tear... a jamming advance plate... something physically wrong, not a fixed value like the plug design.

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I've been calling it as i see it for my entire life and that's not about to change. Take it or leave it.

I did not think so either and as I "thought" that I had mentioned that immediately as I obtained the truck, I replaced the cap rotor wires and plugs and have NO history of how it ran with the Champion RN 12YCs in it (they probably were not original by the amount of wear they had on them but as hard as they came out they definitely had been in there for a WHILE. but being that I had also never used the ZFR plugs, I had to ask; I filled it up with Amoco reg grade (which is supposed to be a top brand of fuel) prior to heading home and topped it off with their "Ultimate" about 2/3 of the way home, which did seem to help; though the road was flatter the rest of the trip than it was up to that point. In what I think is a short time of ownership I have already put ~1350 miles on it and have tried 89 octane in it and it ran no different than it did with the 87 I originally put in it (I got the truck on "fumes") I am wondering about the distributor's condition as the symptoms do seem erratic. I may have to go pull one (or a few) at the local yard to build myself a known good one. I'm gonna have to check with my auto shop teacher buddy to see if he still has his ol' Distributor Machine or not. I do have a dialback timing lite (so I could use the engine as a "dist. machine"), but it's just easier to work with, out of the truck. Another reason that I am looking for an '83 factory serv. manual, so I can compare to stock specs what this thing's doing as a baseline before I try and change anything.

OK...
It's a 1983 truck?
If the ESC computer is gone, what distributor is in the truck? 1983 would be a locked out dizzy with the computer doing the time... In which case if someone just 'set' a locked out dizzy to some random spot, I'd be worried.
If the dizzy is EI with vacc. advance, then what is the tag number on it?

Another problem that can exist... if the engine is the real 1983 cast crank hydro motor... it would have a BL head stock...which means no ZFRN plug (the plug can be inserted,it may not seal properly without spotfacing the plug seat faces...also the plug thread depth is different and will change the spark kernel "WELL" into the chamber...which will promote pinging)...
Did someone pull the late mill and put a pre-75 drool tube mill in?


???

-D.idiot

No, its not an original LB truck; I thought this would simply be a quick yes/no type question about the "extra" extended reach plugs, since I had not used them before (had always used Champions with good results) but tried the ZFRs on Dan's recommendation; my truck has 2 "extra" cyls (318)

While I do not currently own a /6( but have 2, Jeep 4.0s) I have owned several /6s over the years (+ keeping Dad's /6s that he's owned, running over the years) ; and unlike some guys out there, I don't "dis" the /6, just because I don't currently have one. I try to help other guys that still have /6s from my experiences with them, and also with tech that has nothing to do with what is under the hood. This is beginning to sound like an overdue "new member welcome" type deal, but I originally came here, looking for a better home for a /6 than most people give them (and Slantzilla provided that, thanks) because I knew that I had one at the time that deserved to live on in someone else's vehicle. And learned alot, met alot of cool people so I hung around. So I stay.

That's cool, we wouldn't toss you out; I've chit-chatted about the 318 in my '89 D100 on here before. I have to imagine an '83 318 would've had lean burn, with a non-advancing distributor, yes? My '89 has in past (closer to stock) configurations been very sensitive to initial timing; spec is 10° ±2°, and if I dared go a single degree earlier than 12°, it became the Ping-o-tron deluxe...

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Nope; no LB; 4 pin (connector has space for 5th pin as older Mopars had) blue EI box, vac adv can on the distributor; underhood stickers (specs or vac diagram one) don't say a word about LB, so I'm thinking it's as O.E. my brother's old '85 D 150 was set up the same way; but I believe his was some kind of "fleet" truck, prior to his ownership. i've seen that make a difference in whether a given vehicle got which ignition system before. I see several '85-down "twins" in the JY and as long as they don't have a /6 they are regular Mopar EI as well. there are at least 5-6 good distributor donor candidates out there. (I'd like to verify a good one and just swap them so as not to have any down time)