Changed plugs...interesting

[SHOdded]

Are you running 93 fuel on the 91 tune?  Just to see if that helps.

[ivofe]

Got the 91 v7 tune in it now didn't help.

[ivofe]

Sorry didn't really answer the question! Yes I'm running 93 Octane with the 91 tune , It did not help. Weird only does it when cruising not from a dead stop.

[FoMoCoSHO]

Regarding MAC98SHO

Just FYI,

For some reason the stock tune seems to run rough until warmup.  The 93 tune I have does not..  Even after running a tune for over a year I went back to stock for some service.  I've been running the stock for 2 weeks and noticed again it runs pretty rough at first.

They both (stock and 93 tunes) ran rough for me.  But, .032-.038 mix and match factory gapping probably did not help the start up idle on either tune.  LOL

I did some logging on the LMS new tune .  I'm still experiencing shudder above 4500 rpm.  Logging shows boost max at 15.7 psi and is showing knock sensor retard during this.  It also shows throttle actual drop from 100% down to around 60% during the retard.

Note:  this is usually only when in already driving 30mph plus the WOT.  For sone reason I don't notice it from a dead stop 0-80 mph.

Does the car downshift to 1st? Mine does that when I punch it at 25 sometimes.

Sometimes all 4 break loose and TC blinks and sometimes not.

I think the car doesn't always like 350lb/ft of torque being applied instantly...

[JMR76]

Regarding MAC98SHO

Just FYI,

For some reason the stock tune seems to run rough until warmup.  The 93 tune I have does not..  Even after running a tune for over a year I went back to stock for some service.  I've been running the stock for 2 weeks and noticed again it runs pretty rough at first.

They both (stock and 93 tunes) ran rough for me.  But, .032-.038 mix and match factory gapping probably did not help the start up idle on either tune.  LOL

I did some logging on the LMS new tune .  I'm still experiencing shudder above 4500 rpm.  Logging shows boost max at 15.7 psi and is showing knock sensor retard during this.  It also shows throttle actual drop from 100% down to around 60% during the retard.

Note:  this is usually only when in already driving 30mph plus the WOT.  For sone reason I don't notice it from a dead stop 0-80 mph.

Does the car downshift to 1st? Mine does that when I punch it at 25 sometimes.

Sometimes all 4 break loose and TC blinks and sometimes not.

I think the car doesn't always like 350lb/ft of torque being applied instantly...

It will break loose sometimes, but that wasn't the issue.  I usually have TC off completely.  I posted in another thread, which others were having issues with the tune in could weather.  It was running rich and the fuel rail pressure would drop around 4300k or so temporary.

[TouchOfEvil]

Winter fuel is the go to answer for this problem, it however is not the fix. The fuel rail pressure drops off sharp at 4k-4500 rpms then it gains back pressure and the stutter goes away.
I called today to get an update and was told they were on the dyno testing out a boost a pump to try and cure the pressure drop.
Guess it's a wait and see thing for now.

[DJE624]

You guys are talking about the tunes for the 13 SHO and Explorer, right?  I haven't heard of these problems with the 2010-2012 SHO.  Even with the new 4+ coming into winter.  You are almost making me think about going back to Stage 4 for the winter.  Maybe even Stage 4/91.  There are only 2 stations nearby that have 93 so it would be easier.

[JMR76]

Yes mine is 13 SHO and only started with the 93v6 tune.  v7 is working a little better for me right now.  I didn't have any problems last winter with the 93v4 tune.

Sorry I had to cut my post short.  I was going to explain it, but got called away.

[DJE624]

NP  I was just wondering about our 4+ with the extended boost curve. Luckily, I haven't heard of any problems with it.  Hopefully, you guys will get a v8 or xv1 pretty soon!

[Needmoreboost]

First time Ive driven the SHO in colder air.  Ran her out a few times in 36-38 degree air.  Wow!  Runs great with Unleashed Tune.  Car feels like its making more ponies versus 80 degree air.  Lol. 

[jimmyducati]

I have a '10 SHO and replaced the plugs last month... Gapps were crazy from .025 to .045, leading me to think they don't do anything with gaps when the engine is built.. a tad disappointing when buying a $45k car if you ask me

I replaced them with the recommended NGK plugs, properly gaped and it runs smoothly now. Also wrapped and shielded that knock sensor wire that runs along the drivers side front head. It gets chaffed and can cause the timing to retard randomly.

A suggestion, on cars with some mileage on them (35k+) I would have some of the rubber boots that hold the spring that makes contact between the spark plug and coil on hand. 2 of mine were "fused" to the spark plug and had to be fished out with needle nose pliers, ruining them. They are only a few bucks a piece.

[n8rfastback]

Ive got 71k on stock plugs, i need to change mine out asap

[ivofe]

LMS just sent me an updated tune, I'll post the results.

[black99lightning]

70,600.  Changed the stock plugs with some new SP534s.  $3.99 each at Oreillys.  The gaps were 38 all around, and black.  Been running LMS 4+ forever.  I'll post pics soon.  Regapped he new plugs to .30 as they were all .32.  Started and idled very smoothly.  Took it up the road and it pulled nicely, not sure if any faster, but definitely smoother.  Question is why are the plugs black?

[Needmoreboost]

70,600.  Changed the stock plugs with some new SP534s.  $3.99 each at Oreillys.  The gaps were 38 all around, and black.  Been running LMS 4+ forever.  I'll post pics soon.  Regapped he new plugs to .30 as they were all .32.  Started and idled very smoothly.  Took it up the road and it pulled nicely, not sure if any faster, but definitely smoother.  Question is why are the plugs black?

SSSHHH...don't tell everyone about the Motorcraft (NGK) plugs that are 8 dollars per plug cheaper than the standard iridium NGK's.  LOL

Strange, mine where all pregapped at .030 out of the box.  Black is probably due to the direct injection and age of the plugs.