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Discussion Starter #1
I just recently pulled my plugs and gapped them out to .055. I put a new cap and rotor on. And the plugs and wires are only a few months old. I also put a new motorcraft coil on. Earlier on I had advanced the timing to 12.5. This was when it was colder outside. The power and mileage gains from just that were immediate. I guess I gained some power and mileage from the bigger spark gap. But, even before gapping out the plugs, my mileage has been going down steadily as it warms up outside. And it is pinging every so once in awhile, but not very often. So, my question is would this be the timing or the spark plug gap? What kind of problems would a wider spark plug gap cause? Doesn't seem to be misfiring. But, I think there is a very small amount of detonation going on. My other question is the bigger spark gap going to ruin my new coil and cap and rotor by stressing it to much? The other thing is when I did the timing at first and I have never touched the timing before, it was set at 8 degrees BTDC. I don't think the shop touched the timing either. So, 8 degrees might really be 10 degrees, which means it might be at 14.5 degrees right now. Just a thought. So, I might back down to 11.5 to be safe, which if the balancer is off, that would be 13.5.
 

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If you are getting any amount of pinging @ 12.5, put your timing back to an indicated 11* and try it again. If it still pings on a hot day, put it back to the factory setting of 10* and leave it alone.
A .055 plug gap won't hurt a thing but if it worries you, put them on .050 instead. You won't notice any difference in them two settings one way or another anyway.

My truck gets better gas milage in cool weather too. To be specific, about .5 MPG better @ a steady 60 MPH.
Me thinks that is due to simple physics.
We can't change physics.

Without having your particular truck here to look over, I can't give you any more advice on what to do with it. Could be that your balance ring is off a hair and causing your readings to be off. Could be that you're getting excessive oil inside the combustion chamber. Could be that your exhaust is restricted enough to cause excessive heat to get get trapped in the cylinder. Could be that sometyhing aint quite right with your EGR system.
Heck, who knows?....Lots of things will cause an engine to ping.
About all I can say for sure is that if you bumped the timing and it now pings....back it off a hair 'till it don't. That, or try a better grade of gas.

Folks here are trying to help you but I'm beginning to think that we aint making contact...if you get my drift.

DGW
 

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Discussion Starter #3
So, it would be the timing that is the problem not the spark plugs gapped out to .055? I really don't want to have to the pull the plugs again, its a pain on our vehicles. I ll try 11-11.5 degrees timing.
 

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From the factory, Ford often set timing below the specified "10° BTDC". There is also variance that occurs as engines age. Timing chains stretch; parts are within tolerance, but still vary; carbon build up increases compression; etc etc.

The larger plug gap is only to create a larger flame front to more fully combust your mixture. The reason people use a "hotter" coil, is so that it more easily can span the increased gap with a strong charge. Your gap could be the problem if you are not running a hot enough coil, so you are not achieving full burn, and in conjunction with increased timing, you ping.

Advancing the timing will also cause ping. It doesn't matter if you could go all the way to 20BTDC or only 11BTDC, as long as you are as advanced as YOUR engine will go.

Fuel will also cause ping, if you have a low octane and are increasing the compression ... which advancing the timing will do. What I have always done in the past is set the timing until it just starts to ping under wide open throttle operation ... then I back it down one degree at a time until it quits pinging ... of course on a warm summer when engine is at running temperature.

You did pull your "spout" connector when setting the timing, right?
 

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Discussion Starter #5
I am running a brand new Motorcraft coil, which Sig says has plenty of power. The wires should be okay. They are platinum plugs, but are Motorcraft single platinum, which are not ideal, but should be fine. I actually advanced the timing yesterday to 13.5, what the six litre tune-up says. I don't know if its pinging or not. Under heavy acceleration, there will be a clunk here and there from the engine every once and awhile, but nothing consistent. But, even if it is not pinging, it might not be the most efficient setting? Because it seems like I lost power and mileage when the weather warmed up. So, I might be better off backing the timing off for the summer? And yes I pulled the spout con.
Thanks-
 
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