Throttle and Jake brake issues on 2014 Prostar

Umm I think it could be the "gas pedal" on your Diesel engine...BAHAHAHA
just kidding driver.. My prostar did something similar,but it was my cruise control sticking The throttle would stay engaged so they changed out the controls on my steering wheel and worked fine after that .

 

My freightshaker did that. Cruise and jake both out, engine would rev up and override the governor then turn around and stall to 55mph then come back etc. Of all the random things to go bad it was a clutch switch. Throttle position sensor also comes to mind with these drive by wire engines. Seems like a starting point. They didn't find it until it went out all together. And never once saw an ECM code.

 

Sounds to me like it might be the accelerator pedal position sensor being out of adjustment. I have not worked on anything that new, so I have no idea if it can be calibrated like it can on my personal vehicle or not. These rarely, if ever show a trouble code in the computer. Looks like Nighthawk beat me to it. I could be wrong, my mechanic skills are a bit rusty.

 

What he said

 

are you taking it to tri-county in Dearborn?If so,try Nollenberger in Monroe.Much nicer to deal with.HeavyD should be along any time now.He knows his stuff!

 

Here I am! LOL! It does sound like the throttle pedal is sticking. This would explain the erratic behavior and loss of engine brakes. If the throttle isn't coming back to full idle, because it is sticking slightly, you will have no engine brakes. The pedal itself still has a hinge and pin with a roller that may be tight some where. The engine brakes on with a brake application is a programmable parameter that can be changed in two seconds if you want. Unfortunately, you are kinda stuck going to an International dealer for issues like this. No one else really has the diagnostic equipment to dig into stuff like this. As far as that dealer goes, well, I am sorry you had a bad experience there. Please remember not all dealers are the same. Warranty does not pay very well, and they do not pay to fix trucks that do not show a problem. From an owner operator view point it can be very frustrating. Some dealers do take the time to try to induce the problem, but it is hard to justify sometimes having a mechanic road test a truck for an hour to try to get the problem to pop up and it doesn't. That hour of time is basically lost to the dealer because warranty won't pay for it. A lot of dealers do not dig in to intermittent problems unless it is staring them in the face. Also, is does this engine have the DEF system on it?

 

I had same issue with jake on prostar, it started working normally after about 20k. Almost like it had to learn when to work. It was a 2013. Didn't have an issue with throttle though.