Hesitation in boost and high rpm

I have a hard time with their answer.. I have their most aggressive non-meth tune (4+x Race Tune) and the LOWEST I have ever seen my rail pressure drop was 1950psi...

Even Torrie doesn't like lower than 1500psi and he is a bit more liberal with variances in rail pressure than LMS...

Weird.... I'm glad they troubleshot it without charging you... the resultant answer is a bit baffling....

Are they still looking into it?
 
StealBlueSho said:
I have a hard time with their answer.. I have their most aggressive non-meth tune (4+x Race Tune) and the LOWEST I have ever seen my rail pressure drop was 1950psi...

Even Torrie doesn't like lower than 1500psi and he is a bit more liberal with variances in rail pressure than LMS...

Weird.... I'm glad they troubleshot it without charging you... the resultant answer is a bit baffling....

Are they still looking into it?
Click to expand...

From what I understand they are looking into it as I am not the only one. Unfortunately Andy the shop manager was out last week which is probably the reason for the small amount of info I got. I am still chewing on all of this as I am still not sure what resulted from driving out there.
 
Recap:
  • From time spent with AJP we know the issue is at a deeper level then just LMS tuning.
  • Confirmed that both pumps are new/mechanically working correctly.
  • Confirmed that car is making expected horsepower.
 
polskifacet said:
StealBlueSho said:
I thought you said at lower rpms? I am confused... so I am guessing that a 0-60 pull is when you still have issues? Maybe I am misunderstanding?
Click to expand...

0-60 or pretty much any time it downshifts @ WOT
Click to expand...
Can you post a log of one of those WOT runs done after your last trip to LMS?  I am skimming the thread trying to catch up, but it would be nice to see a WOT run log of the current tune with all the current new parts and any tune changes they might have made.

As for Dyno, how did they dyno it?  Based on the smooth RPM curve it was the classic 3rd gear locked in pull.  They are not seeing WOT shifts (I do not think Dyno's can handle that sort of jerking), so not surprising they did a single gear pull, but it is something to keep in mind on why you are still having an issue.  Because of that sort of dyno tuning they will never see the issue you are having, as it is a nice flat/linear (while heavy) load pull they are doing.  A tuner cannot tune for something they cannot "see".  Dynos are great tuning devices, they just cannot simulate full range driving conditions.  I would have thought based on what you have been saying all along that they would have taken the car out someplace to really simulate your issue with WOT&shift performance.

I will probably deserve a Gibb's slap for this...  You have replaced all the pump side stuff already, but have you changed the fuel filter/blown the fuel lines clear during one of the times you have had to tear things apart?  Have you traced the hardlines and made sure one of the hardlines is not dinged, or kinked someplace?  How about soft lines?  Any sort is small deformation or restriction can cause it to have a hard time recovering from sudden spikes in demand. Might be "ok" on smooth RPM ramp up, just enough headroom to keep up, but not flow enough to recover from demands like can happen with WOT shifts as well as sustained demand staying WOT.

I am new to these cars myself, but think Steel might be on a good track.  You are talking with AJP, have you considered his boost regulator mod?  It takes the stress off the Fuel system post WOT shifts and keeps MAP constant and level the entire time without messing with the throttle blade.  Might be a bandaid to underlying problem, but I would be curious to see how your car did with that mod installed and tuned for it..?
 
Even on the third gear sweep he posted his fuel pressure is lacking.... I doubt the AJP mod will help much..
 
Everything fuel related was checked at least twice and LMS also would have seen LPFP drop when they supposedly had the gauge hooked up under the hood. I think it is narrowed down to fuel leaking which would be weird as its not running rich and I'm getting 28 mpg highway or there is something wrong with how the ecu is controlling the HPFP.
 
Yea, they probably hooked up a gauge to the schrader valve under the hood up top on the passenger side. If that is good then you can say everything from that point to the tank is probably ok. Then a visual on the lines which are very easy to see to the HPFP.. then after the HPFP you can trace to the start of the rails...  to inspect it further would require you to remove the intake manifold... don't think they did that... even if you did, not a WHOLE lot you can tell visually from that point...

I am not sure where the sensor is that picks up the rail pressure...

If it was a leaky injector he would be having other problems too... stuttering while idle among other things...

Honestly Brad has mentioned with mine anyway, that there is logic in the ECU that SCT can't see that maybe at play with fueling as well...

Hope LMS can get to the bottom of it for you.. again... I have a spare LPFP, FPDM, and HPFP... if they come back saying you need one of them, let me know...
 
I highly doubt the FRP was even checked as mentioned above by StealBlueSho.
Its just to many variables to consider in this situation!!. Z
The wiring below is for a 13 SHO and will certainly try to see what i can dig up in the FSM.
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Here is another 89 tune log where it downshifts into first gear at WOT and has the most trouble with 91 or 93 tunes. It never shifts into second normally when I do this. If I wot from a dig, there is no issue. Fuel pressure matches desired.
 
hmmm interesting.. you fuel trims don't look off... but yea.. I can see it...

Your desired tip and desired FRP both drop.. your wastegate duty cycle goes to zero...and your throttle closes up almost all the way.. I bet it feels like the whole car comes to grinding halt!

The weirdness is you usually see this when you are running out of fuel.. BUT I have dropped to 1000psi before the throttle kicked in to save pressure... yours is getting to around 1500 psi.. PLUS your dsd frp is requesting a drop as well.. weird.. Brad might have some better insight..
 
There is obviously something different with certain strategies / pcms. In my case brad also was like WTF so I have a double ended poop stick lol
 
If i put it in sport mode and use the paddle shifters so it holds gear, it pukes on itself pretty much every time, misses the gear, bounces off the rev limiter etc first to second upshift. In D or Auto S mode its fine.
 
I dont think its the strategy....i still think its a hardware issue.

I see that you have a 1000 watt subwoofer...i wonder if there is a grounding problem or a battery draw....maybe we should log battery voltage during the pulls and when the issue presents itslef....injectors do very strange things when they dont get the power they need as well as the intank fuel pump...this just occurred to me

You should get your alternator and battery checked...you might understand why but its important for the fuel delivery
 
ive experienced low voltage on a different vehicle and what it does to power/fuel. Battery was replaced right before they changed the long block. I monitor voltage when I pound the sub and its always 14.x. Trans is also acting up since the beginning.

I have an extra 4 gauge ground going to the shock tower and have cleaned all the stock grounds.
 
I have to agree with AJP assessment above and would try to rule out it being a voltage drop in conjunction with it's battery components causing your issues by checking the ground cables and straps for corrosion by the engine bay and curious if your issues started after installing the high powered system.
Did you install a good quality capacitor?
I wonder if disconnecting the power/ground from the amps for a couple of days has an overall effect on the performance of the vehicle!!.
I found an interesting thread over the Flex forum which might be somewhat beneficial.IDK. Z
https://www.fordflex.net/forums/viewtopic.php?t=9276
 
I feel like ive done my due diligence on the power/ground front. I also don't have the radio on when testing or spirited driving. I would look deeper if I was experiencing any issues on non lms modified "systems". Once I go to 87 octane tune where its completely stock values on the engine side, it works like its supposed to and only the trans is modified which I still have issue with it in (sst?) mode but no such issue in D or S. I can put it back to stock and I am 99% certain that I can't reproduce any of the issues. I have emails that all the issues were brought up to lms fairly soon after I bought the tune. I had zero drivability issues prior to installing the tune.
 
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