Something else I also read last night was in the Ranger and Taurus forums that some guys where having problems like this running hot coils. I believe hot coils refers to high output. Just thought that was interesting.

Another side note: Accel has the worst reliability record for COP coils, -single coils. Fluctuations then go dead.

But many have bypassed that all together using the standard Visteon brand which is Motocraft. That was from the crown vic and lincoln mercury forums.

That was just a few things to keep in mind that I noticed.

 

What makes sense to me is with COP system coils, now and in the past, the HO coils, such as Granitelli, Accel, Weapon X, Moto Blues for these engines have all been problematic. Some more than others, but that could be because of popularity amongst users.

All we actually need is a low volt signal that the coils can convert to pulse. It's really nothing special, with the exception that the coil needs to have that ability and remain consistent. That said, factory coils win out over anything else on the market. The HO's burn and short they're windings, shorted turns add up to , -at first - low grade misfire, then dead if you can put up with it that long.

 

Sam's gas is pretty nasty - and there is no reason whatsoever to use 93 octane unless you have a 93 octane tune or it pings on anything less.

I'd bet the extra additives in 93 may have something to do with the red stuff.

Best gas you can buy for cleanliness is Chevron or Texaco. They have Techron in it.

 

I do have a performance tune on it form superchips it says to use 91 or higher, I tired it on lower oct and it does ping/knock, even before it was tuned it. Bone stock, I got better mpg form using 93.

Yes I do agree, I also have heard walmart gas is just as bad. I used to just get it wherever I was at, but here lately been getting it form sams. I asked my mom if she had any problem, she and my dad also get gas form sams. Never had no problems, I did some thinking and all the gas I got in the last week or so was form sams, my parents got gas the week before that. Im thinking sams got a really bad load and lucky me I won, didnt even sign up.

Tonight with all this on my mind, I went and got the best stuff that I know that actually works, lucas deep clean fuel treatment. And you want never believe what happened: The problem is almost gone, I have the most power I have yet to have in a while. Im happy, when I went form flooring it and sitting there for a second or two, to flooring it sliding sideways. Id say thats an improvement.

I still have a little shake, and that small bump at 45mph I have noticed it doesnt do it with overdrive off, the bump has almost turned into a vibration, cant be u-joints. I been reading about the f250-up owners having the same issue. They have found there problem to be the slip joint not greased enough or wore off. Which it sounds like my issue, we will see.

However I think that I had two problems rolled into one. The rear shudder issue, and also a low grade misfire of somekind. What I think has happened was the shudder problem was there the whole time its just been so lite I never felt it, until the bad gas that caused a type of misfire, therefore it felt worse than ever. Not sure if the problem is the slip joint, but we will see.

Follow up on things done: Changed over coils to M/C, Cleaned plugs, Cleaned fuel system(lucas), Changed tranny fluid(pan), Added extra gear oil to diff, Checked: U-joints, Rear Suspension, Every nut and bolt i could find. Rotated rear tires.

Things left that will be done by the weekend: grease slip joint, replace fuel filter, swap out the one last coil, double check everything. Then enjoy whats left of my weekend.

 

^^ Ok, but I wouldn't just clean the plugs - I'd replace them. Unlike a 3V, they are not that expensive, nor onerous to change.

And - you'd do well to use Techron as a fuel system cleaner.

MGD

 

Yes, Techron is the best additive, not Lucas.

For whatever reason, I get terrible gas mileage on Sam's and Walmart gas compared to the other gas available here (mostly Conoco/Phillips).

If you have a 91 tune, yes, you have to use at least 91.

Your pinging before the tune was probably due to combustion chamber deposits, from using gas deficient in additives. If you want to clean it RIGHT, go spend the $$$ for a BG or Motorvac intake cleaning job. I have this done with every spark plug change, and to ME it's worth the $140 the dealer charges.

 

think i might go ahead and replace them, as of a few mins ago i found them for $2.49 ea and if i get my friends discount they go to $1.99 and yes that is sp-493. ford wants $4.50 ea. think i might load up on a second set there very cheap right now.

as far as fuel treatment i have tired everything on the shelf. And the only thing that i have actually felt work and done little test nothing major to hold up to. I have only found slick50 and lucas to work, after doing some of my own research i found that both are very close to each other. Not saying techron is not a good cleaner, just stating my own opinion. I would say a good 80% or more of the so called treatment are mostly kerosene. I have opened them and you can smell it, so i did that the all of them over the years and the two that i couldnt smell it was lucas and slick50 which is why i tired them and i still believe them to be the best of what i have tired. I will say i have used more of the two more the anything, and i have not used techron that much. Next time it goes on sale i will get some. I stock up on stuff when its cheap such as this.

I was wondering if i should go ahead and change the plugs out, even thru everyone fired correct, but when you mention to and now found out there $2 a plug. Heres my sgin.

Thanks for all the great info and time, I might not be back on this one till sat when i get everything left done.

 

So umm I think i might have another problem, or have overlooked it. When im going to around a corner form dead stop both tires spin and it takes off fine. Cant explain that one? Other then it still may not have enough modifier in the diff. Dont know but i wil drain some out and add another bottle is only 7oz In the past diff oil changed i have had a problem with not getting all 7oz in somehow, tired if a few different ways it never worked out, so ill add that to my list of things to do tomorrow. my buddy owns an exhaust shop with two lift/racks, that should be real easy to do everything i have planned tomorrow, fuel filter, grease slip joint, add some modifier. shouldnt take to long.

 

Sounds normal, what's the matter ? When there's a problem with the LS's in these rear ends, the problem manifests in over slippage. The over slippage feels as tho you went into neutral and when turning right or left. It's actually a clutch pack problem that can come an go. Largely, this happens when changing something up, like the rear tires.

All overfilling might do is overflow at the breather. Adding a little to much modifier won't harm anything, -just very little, no more than 2 oz's over imo.

That's basically how it works when over and when you have an actual problem, - unless it's vibrating back and forth. A little hop is normal. They all do that to a certain degree.

Maybe your nit picking, maybe not. From the sounds of it, you might be.

 

The main reason I started this post was because of the simple fact. It just started doing it a month ago, never has done anything like this in the past. I got it new with 67 miles on it. I cant find anything in my past records that say that state any problem. Now if i find out it is a normal thing for it to do thats fine. This issue randomly starts overnight, is whats bothering me.

I will admit i am what everyone would call picky, but it is also a good way to notice things.

My records since jan 2012 starting then i changed the engine oil and filter at 62k 1-14-12. Changed rear end oil 1-31-12 63k. then there nothing till may 2012 and that was installing a gatorback belt, and cleaning the maf was at 67,500. Of course the tranny fluid change right behind it.

I just have an over worry issue that when something happens it gets stuck in my head and i have to do everything i think it might be to try and fix it. Once i get everything done i will then be happy, but as of right now, i still think there is a problem and want to make sure that it either gets fixed or clears my mind. lol.

Hmm interesting just found something that might be of help. Last time i changed the rear end oil, i have it noted that i was unsure of the amount of modifier to add so i added two bottles to be sure. I noticed that when i changed the oil back in jan, but paid it no mind cause there was never any issues. Went with the right amount this time and left it at that. Maybe?

Another thing i just thought of but i doubt it would be the problem, the tires on the rear ARE the same size 235/70 however one is near new and the other is almost gone. Could be?

 

You effectively have slightly different diameter tires on the rear, and this is hard on the LS.

 

Well, I took mine to the dealership, as it was still under the 90-day powertrain warranty they offer for used vehicles. They couldn't get any codes to show. The tech suggested, like I predicted and most everyone also said, that the plugs needed to be replaced.

The service manager fenangled the wording of the problem to get it to fall under warranty. Thank god he did, because 5 of the plugs broke! I have to pick it up this afternoon, so I will see if its still misfiring.

 

Yea, they can get wacky or picky you could say. I put new tires on the truck and right after, I got a little slip on right turns. Bugged the hell out of me. The rear end was accustom to old tires, believe it or not.

Well, I finally fixed that by taking the trans mount bolts loose, then realigning. It WAS a little off according to my chalk marks. Just that little bit fixed it.

Made sure the axle was straight, it wasn't perfect, but straightening that didn't cure. So I made sure everything perpendicular from the engine down was straight or aligned. It wasn't until I nudged the trans/transfer case over a taste to the mark, and with a piece pipe, that it was cured.

 

I do agree with that in the past i have had two different size tires front and back, both back being the same size, and the front being a smaller size to the back. I thought my abs light was broke it kept coming on so much im talking maybe a 1/2" between to tire tires sizes. So yes this rear end is picky.

However i went and got me a new used tire to match the other one, well when the guy went to brake the tire off the rim just barely touched it, and it blew right in the sidewall, that was kinda scary to think it was that close to blowing. But when it was all said and done it still didnt fix the problem. So i went to my friends shop who has lifts, we re-greased the slip joint found it to be a little dry, we thought for sure that was the problem, still nothing. Next thing on my list will be the spark plugs, and i will prolly have them in by tonight. If not morning, And will let yall know then.

 

Well guys the plug change did nothing but make it run better then it did, im sure i would run better to if i had all new parts. But problem is still there. I got my last coil should be here tomorrow, but i highly doubt that will help anything. Fuel filter wasnt changed either again dont think thats it.

Only thing thats on my mind is not having enough modifier. Back in my records i state i added two bottles of it in the past, which then i didnt have no issue, however then only thing is, the oil thats in there now was changed back in jan. So my only question is, if this is the problem why did it take 4 months to so up? Did it take that long for the old modifier to wear out? I went form 75w90 full syn with two bottles of modifier, TO, 75w140 full syn with maybe one bottle???

Other then this. Im about to give up all the whole thing.