Throttle stuttering on acceleration

Discussion in 'Ford Raptor Engine Discussion and Performance Mods' started by caleb, Jan 28, 2018.

  1. Booth9999

    Booth9999 Full Access Member

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    93 a California can dream....
     
  2. 03'Darin

    03'Darin Full Access Member

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    Unfortunately no updates. As far as I know the complaint percentage for this issue is so low that Ford is not addressing a fix. It's ALL in the programming. mezger described very well what is going on. The truck is trying to maximize the power based on fuel quality, octane, IAT temp, load and so on.

    As I mentioned before the new Navigator has the same tuning. Hopefully those buyers complain enough about it and that starts the process of a fix.

    I think I've sold 13 Raptors so far. I have one customer besides myself that has complained about this issue.

    Also just a not it's much more noticeable in cooler weather.

    NOTHING will fix it besides a PCM update for the problem.

    Grade or brand of fuel won't change it and the other spark plugs won't change it. So don't waste your money trying that stuff. Our lead tech and I have data logged the issue for a lot of miles and sent several files to Ford. They are not working on a fix as of my last contact with them about 3 months ago.
     
  3. 91Eunos

    91Eunos Member

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    New Raptor owner and just found this thread.

    My ‘18 is doing the same thing. In fact, it was so bad when we test drove it, I thought the tires were out of balance or flat spotted. Clearly it got better but what I thought was them fixing a tire balance issue (they said tires were good...and they were/are) was likely just that the truck’s engine had warmed up. It only seems to happen at part throttle, but I do notice it more when the engine is cold. What I’ve recently noticed is that my instant mpg meter is spiking up and down about 1/3 to 1/2 of the total range...very rapidly when I feel it...with constant throttle or even with the cruise control on.

    It sort of feels like I’m going over rumble strips...like the kind they put across the road to warn you when you’re approaching a stop sign at some intersections. Just a bit of a rough/jerky/bucking feel...not egregious, but definitely noticable.

    I only run 93 octane or better; typically Shell VPower, but sometimes Chevron (with Techron!) or occasionally whatever name-brand gas Costco is selling this week.

    I’ve already cleaned the sensors (nothing of note), and will try the 542 plugs this weekend after I do the brakes on my wife’s Jeep...will also go ahead and dump in a bottle of Techron or Seafoam into the tank to ensure the injectors aren’t partially plugged. Since I’ll be in there, I’ll check the sensors again and take the intake system off to see if I can see any oil film...will check the throttle body too. Hell, since I’ll be in that far, will go ahead and run a can or two of CRC cleaner through there to at least partially clear any carbon deposits that may have already formed on the intake valves. Yes, I know the only way to truly and completely clean them is to disassemble the heads...or maybe media blasting, though the risks/downside of that make even me leery.

    Regardless, will also schedule an appointment with my local dealer to have them test and data log... Worst case scenario is another data point for Ford. Best case is that maybe it’s just plugs or that my truck may just need an updated ECU flash.

    Will post results.
     
  4. ArmyTanker

    ArmyTanker Member

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    I purchased my 18 Mag Grey Raptor about 2 months ago. I added a Roush CAI and peddle commander. I too had noticed a sluggish throttle tip in point, mid range throttle delay and some surging feeling under full throttle. After joining the site, just been looking around and this is my first post. This thread was of great interest due to it matching many of my concerns, so today I decided to try the SP 542 plugs, left them gapped as they came out of the box. After installation, went for a test drive to the grocery store for the Wife. On the way there, throttle felt way better but noticed I had some pinging at mid to full throttle. After stopping at the grocery, back on the road and the pinging is gone? Any guesses why on both??
    The throttle seems better throughout, used to it would seem you have it throttle and it would take a millisecond and then it would cone in hard. Now, it seems to come in instantly and smoothly as you apply more pressure. But because it doesn’t come in delayed and hard as before, can’t yet tell if it makes the same power overall, but it is way smoother. The pinging happening and going away, does concern me, any wisdom from the group would be much appreciated. Many thanks
     
  5. smurfslayer

    smurfslayer Be vewwy, vewwy quiet. We’re hunting sasquatch77

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    There’s 3 things here.
    1) confirmation bias. You want the new plugs to help, subtly they may, or may not. They could even make it worse in the same way that a car with a peaky power curve “feels” faster when you hit the power curve, but, the car with with the smoother power curve leaves you in the dust.
    2) there could have been a bad or badly gapped plug, maybe you did fix something.
    3) the throttle stutter was debugged by @03Darin, and it’s persistent in the F150 model line. All Raps have it and will do it under some circumstances with the current programming.

    if it’s running well, take yes for an answer.
     
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  6. 91Eunos

    91Eunos Member

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    Small update from my end. Did the 542 plugs yesterday and confirmation bias or not it “seemed” to run a bit smoother.

    Double checking that the 542s are the same length as the stock plugs before putting them in:

    [​IMG]

    All 6 of the old plugs looked normal to me...no real concerns from what I can discern:

    [​IMG]

    Checked the sensors again since I was in the engine compartment and all were oil-free.

    After a short test drive with the new plugs, I also ran a can of CRC valve/turbo cleaner through the motor via the throttle body...took longer than I thought, but had the kid who’s getting my old truck running the throttle, so he was happy to get some time on a Raptor throttle, even if it was just to hold it between 2,000-2,500 rpm!

    After getting the intake back together, took it for a couple towns over to pick up some VP 100 octane, and not surprisingly it was running a little rough at low rpm/throttle until I got out of my neighborhood as residual cleaner made its way through the intake/exhaust. There was a particularly rough ‘stumble’ when I rolled on the throttle pulling away from the stop sign leaving the neighborhood, then a huge puff of white smoke out both tail pipes. Guess some carbon got blown out!

    Ran smooth as silk after that...

    Have a large bottle of Techron in the tank as well as some VP octane boost and cleaner along with another fill up of Shell VPower 93 octane.

    Gonna run it down to 1/4 tank or so and add this next:

    [​IMG]

    Then I’ll do the CRC valve deposit/turbo cleaner one more time.

    After that will do my test circuit again to see if the part throttle intermittent stumble is any better or worse. Suspect it’ll be unchanged if it is indeed an engine map/ECU programming issue where the throttle body is feathering open and closed very quickly ... and which my untrained/unprofessional observation in an uncontrolled environment of the instant mpg bouncing up and down on a smooth road would point to as well.

    At least I can rule out octane as the cause for the stumble if it does reoccur! ;)

    Edit: Has anyone running an aftermarket tune noticed the stumble? If this is indeed just some poor programing, I’d think a tune developed on a dyno would be able to smooth out the unnecessary throttle oscillations...then again, I’d think the factory developers/program managers, engineers, and programmmers would fix that too, even if they are running a compromised tune to account for crap fuel being put in the truck.
     
    Last edited: Nov 11, 2018 at 2:44 PM
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  7. kid icarus

    kid icarus Member

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    Curious why an owner would want to have to put up with this. Why wouldn't Ford just design it right from the start?
     
  8. NASSTY

    NASSTY FRF Addict

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    Very few owners have this issue.
     
  9. 91Eunos

    91Eunos Member

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    Agree... That said, it’s not very noticible, and only occurs in very specific partial load conditions...at least on my truck. I’d even posit that the vast majority of owners don’t notice it if they do have it.

    I’m still trouble shooting my case, and will get it in for a real diagnostic with Ford soon. Remember, mine is a used truck with a late 2017 build date, and based on little things I’m finding believe the first service since new was from the dealer where I got it...doubt they even checked the ECU flash version.

    I’m glad to have the hotline # and a good relationship with my local dealer. We’ll see what they say when I get it in for the next service.
     
  10. smurfslayer

    smurfslayer Be vewwy, vewwy quiet. We’re hunting sasquatch77

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    check out the posts made by @03Darin. there just hasn’t been enough volume of complaints about this. Once the Navigator crowd gets a taste of it, maybe that will change? All of us have the same programming bug apparently, but it only manifests under very limited conditions with steady throttle.
     

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