Pete 587 isx15 acceleration issue

[Alexp86]

When I lightly press on the accelerator it doesnt move, but if I hold it there or push it down further it seems like it catches on and accelerates really fast. Any idea what may cause this issue? Im about to buy a throttle sensor, but not sure if that'll be the issue.

Also it has been jumping when i put it in gear or accelerate from a stop, if it stays in 2nd gear it keep doing it until I hit 5th or 6th then itll stop jumping when it get back down to 2 its like it resets. It only happens every once in a while sometimes itll got 1000 miles without doing it.
when it jumps its very hard makes everything in my cab fly around could that be caused by the throttle?
I did replace all my batteries a month ago and it stopped for 3 weeks but that couldve been just a coincidence cause like i said sometimes it will go a while without doing it.
I did have some trans issues where it wouldnt go into gear, but ended up having the dealer replace clutch and actuator cause they said my inertia brake was broken, but before they did that I was having issues on the road and took it to a shop where the guy didint seem to know what he was doing. He said the software needed to be updated and when he was looking through his eaton software he was like ummm i wasnt sure what version so i chose the generic.... ever since then it started with the jumping also my gears seem to change sooner than it used to ill be on like 6th or 7 by 20mph.

Any help will be appreciated.

[Rawze]

letting those truck wash places power-wash under the hood can cause throttle pedal to act up like that too.

Never let anyone with a power-washer under your hood.

[Alexp86]

I hear you, but I never let anyone wash under my hood. Maybe the previous owner did.
Today while coasting downhill in 2nd gear not touching the acc or break, the truck would feel like i hit the break and make a clunking sound.

[windowrattler]

I have came across broken wires by the pedal. Typically the wire ends up making a u shape under the pedal and after years of flexing the wire breaks internally. You should be able to see the issue when watching the throttle % in insite.

[Alexp86]

(12-17-2023 )windowrattler Wrote:  I have came across broken wires by the pedal. Typically the wire ends up making a u shape under the pedal and after years of flexing the wire breaks internally. You should be able to see the issue when watching the throttle % in insite.

Does that mean the whole pedal needs to be replaced or just the sensor?
It weird cause I was back in it started doing it today again. I put it in reverse it shook the crap out of my cab and if u barely touch the pedal it shook hard again and it would be very sensitive so I put it in drive and it shook hard accelerated to 4th gear and it stopped doing it. Then backing in i would press the accelerator it wouldnt even move until i pressed it further. Idk if its a pedal or torque converter or driveline. I keep trying to find answers online. But all it comes up is sensors, transmission mount n clutch.. ive taken to dealers a few times and cost over 10 grand and being the problem doesnt always happen. They'll say your transmission is fine it didint do it for us etc im not sure whatelse to do.

[tree98]

Anyone who owns one of these engines should have a laptop with the insite program on it and an inline adapter.These tools are readily available for about $300 online.

If you had insite you could monitor throttle position and see if there is a discrepancy that points towards a bad throttle position sensor. You could also look at engine state monitor to see what's controlling the throttle when this happens.

There are countless other things you can do with insite to help diagnose and maintain a cummins engine. Without out it we just sit here guessing and wasting time/money.

You could connect with insite and then go about your day as normal and then when it acts up you can take a look at the data your monitoring.

Has the check engine light come on at all lately?

[Alexp86]

(12-18-2023 )tree98 Wrote:  Anyone who owns one of these engines should have a laptop with the insite program on it and an inline adapter.These tools are readily available for about $300 online.

If you had insite you could monitor throttle position and see if there is a discrepancy that points towards a bad throttle position sensor. You could also look at engine state monitor to see what's controlling the throttle when this happens.

There are countless other things you can do with insite to help diagnose and maintain a cummins engine. Without out it we just sit here guessing and wasting time/money.

You could connect with insite and then go about your day as normal and then when it acts up you can take a look at the data your monitoring.

Has the check engine light come on at all lately?

I didint know it was only 300, im going to look into getting it. I bought a code reader for 500 3 months ago.
No, no check engine light has come on. It just bucks really hard when i put it in gear foward or reverse, but if I move past 4th gear itll stop doing it, but until that happens any light touch to the accelerator will make it buck until its moving. When it doesnt buck if you lightly press the accelerator it doesnt even move until you push it down about an inch n a half. I had a guy tell me the bucking could be the brake pedal too.