Weird, Jerky, Hesitating Throttle - Gen 2 Coyote

[juddster]

I'm in the go kart stage and there is a hesitation, almost jerky response in the throttle. If I give it a lot of throttle there isn't an issue, or if I keep the RPMs low and ease into the next gear it is OK, but during what I would consider normal acceleration it hesitates and starts to jerk. As soon as I let off or give it a lot then it stops. I have a Gen 2 Coyote and the motor is running great, but this hesitation is strange.

Anybody else seen this?

Thanks!!

[JohnK]

Yes, mine was the same (also gen2 coyote). I reached out to Lund Tuning and they were able to provide me with a baseline tune based on similar configurations that they've done for other customers and that helped tremendously. I still plan to do a custom tune when I get the car titled and am able to do some proper data logging, but the "ballpark" tune was a huge improvement.

Edit: You can hear how much I'm having to work the throttle due to the jerkiness in my first go kart video. It's night-and-day different after the tune.


https://youtu.be/i8xHmlo0kFU

[Railroad]

Lethal Performance was running a sale on tuner and Lund tune, $75 off. Might google and see if still in effect.
I have bought parts from Lethal and tunes from Lund. Pleased with both.
good luck,

[Al_C]

Please keep in mind that the crate engine thinks it's going to be installed in a mustang with a huge air box. Mine came with this massive thing that would have taken up as much room as the motor itself in the engine bay. Consequently, when it doesn't get what it's expecting, it doesn't like it. (Yes, I guess I am editorializing) A tune, whether Lund or otherwise, will fix most or all of it. My only other suggestion is to ensure your fuel pressure is where it should be, that the MAF is on the "radiator" side of the intake, that you have the O2 sensors in place and everything else is "kosher". Mine was intractable at low rpm pre-tune, but ran great at speed. I'm confident you'll figure this all out!

[edwardb]

I drove my 20th Anniversary Roadster with a Gen 2 Coyote about 1,000 miles on the base tune. It ran "OK" but wasn't perfect. A Lund tune made a huge difference. Especially noticeable in the lower RPM's where it launched easier and was much happier. Sounds similar to what you're experiencing. I've used Lund several times and they've always done a good job. But (unfortunately...) have really raised their prices. Still recommend though if you don't have any other option. They confirm what Al_C said. A huge fix is the MAF calibration since we're not using the stock airbox the base tune is calibrated for. Off topic, but an even bigger issue with the Gen 3.

[juddster]

Thanks all for the input. Sounds like a tune would be a great thing.

I'll double check my fuel pressure, 02 sensors and MAF.

[Misterfubar]

I've put about 1500 miles on my Gen II now in the 6 weeks I've been driving it and have experienced the same.

I've got a tune appointment with a local shop tomorrow.