Engine Sputters when throttle is hit and let off then hit agian quickly

  • Hey @Lorge it definitely helps to increase the amount of fuel available. I would also recommend the larger fuel rail.


    The issues that these guys are having is pretty much in all the turbo charged slingshots. Someone above said it was in all boosted Slingshot's but I personally couldn't say that to be true because I have never driven a supercharged SS far enough to find out.


    It looks like you are supercharged. So it may not be as noticeable.

  • Hey @Lorge it definitely helps to increase the amount of fuel available. I would also recommend the larger fuel rail.


    The issues that these guys are having is pretty much in all the turbo charged slingshots. Someone above said it was in all boosted Slingshot's but I personally couldn't say that to be true because I have never driven a supercharged SS far enough to find out.


    It looks like you are supercharged. So it may not be as noticeable.

    I think all the supercharger units will do the same thing when you push them hard repeatedly. I also believe it is in the programming. The ecm learns the throttle body position every time you start your SlingShot. Try this and see if it isn't true; start, warm up and go do a hard run. The first time there is no fluttering when shifting, repeat with several runs and the flutter get worse and worse. Now shut down, restart, the first run will be perfect again. Has to be in the program.

  • Thank you guys! At least It feels good we share a problem. Its not life changing and we all seem to be able to deal with it in our own ways, dang are we a stubborn bunch! :) Thank you all for the input!


    Hello everyone, sorry for my delay in responding to this .
    I'm well aware of this problem and one thing we found out just recently as we converted our 12th slingshot to haltech .
    On the alpha we noticed a rich afr until it hit 4500 rpm and then the afr went way lean on a heavy pull .
    We checked a variety of things such as ignition and fuel system in haltech diagnostics mode .
    660 injectors looked good but at 4500 rpm the injector flow rate was 100% which helped us figure out that the fuel pump was not able to keep up.
    We discovered it was still the stick fuel pump . Bingo !
    We tore it out , install a inline with pressure regulator and added a return !
    Boom ! No more popping and alpha system is better but still needs a little more tlc but the haltech system is so flexible and allows us to dive deep and diagnose all aspects of our engines!
    We also went with a cold plug .



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  • Hmmmmm, can you please tell me/us what pump system you changed out to and what pressure do you run or is regulator set already? How does return work(plumbed back to tank)?
    Thank you for input! Joe

    Why buy one when you can have two at twice the price..... :evil:

  • I think @oneshot was correcting for a bad or weak stock fuel pump. The stock fuel pump is good for up to 500hp with the correct injectors. And I don't run a return fuel line. That is usually best on e85.

    I thought I had read that somewhere!!
    I'm not even close to that( I don't think many are)
    Thank you for clarifying sir! Joe

    Why buy one when you can have two at twice the price..... :evil:

  • main thing is getting the Haltech and having the ability for a person to make changes to each aspect of the tune. When you can make the adjustments you need to it's so much better.


    I mean it just makes sense... you can see that when you have the ability to fine tune the ECU it's like having a suit custom made to fit you.

  • Hmmmmm, can you please tell me/us what pump system you changed out to and what pressure do you run or is regulator set already? How does return work(plumbed back to tank)?
    Thank you for input! Joe


    Joe ,
    I wanted to also add that some people that converted to haltech and larger injectors and properly tuned are having no issues with the stock pump and we probably would have been fine replacing the pump with a new stock one but we had plans to run flex fuel so we needed a return system and opted for external pump.



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  • I'm getting sold on that.... like I said, mine has done it since stock right out of the box(lol) so I am pretty sure it's in ECM programming.... I just need to find somebody local to help that knows the SS and has experience, DDMWORKS is far away.... ;(

    Why buy one when you can have two at twice the price..... :evil:

  • Joe ,
    I wanted to also add that some people that converted to haltech and larger injectors and properly tuned are having no issues with the stock pump and we probably would have been fine replacing the pump with a new stock one but we had plans to run flex fuel so we needed a return system and opted for external pump.



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    We are running at 50psi and a aem pump and regulator .



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  • See I told you @oneshot would clarify. I believe he will post some pricing shortly. The actual install is pretty easy. Jamie worked with Haltech to develop a wiring harness to convert it over.

    I sure I could instal it, now getting it to run right is another thing!
    Don't trust to many to work on my baby nor do I want them to experiment to get it right.

    Why buy one when you can have two at twice the price..... :evil:

  • I'm getting sold on that.... like I said, mine has done it since stock right out of the box(lol) so I am pretty sure it's in ECM programming.... I just need to find somebody local to help that knows the SS and has experience, DDMWORKS is far away.... ;(


    Joe ,
    What state do you live in ? I can send you a kit with a base tune for a local haltech tuner to work from or we can arrange to come get your bike and do a complete install for you .
    Ecu , harness , wideband , racepak gauges will run about $3200.00 in parts that I can ship to you and email a base tune .



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