Your situation is not uncommon with diesel trucks and there are several potential causes. One common cause of a delay in throttle response, or ‘turbo lag’, is a failing turbocharger. If the turbocharger is not spinning as efficiently as it should, it can result in a noticeable delay before the boost comes on.
Another possible reason could be a clogged fuel filter. If the fuel filter is clogged, it can limit the amount of fuel that reaches the engine, slowing down the throttle response.
Lastly, issues with the air intake system or exhaust system could also lead to slower throttle responses. If the air filter is dirty or the exhaust system is blocked, it can prevent the engine from reaching its full potential.
I’d recommend getting your truck checked by a professional mechanic. They can diagnose the problem accurately and suggest the right course of action.
Safety and performance should always come first when it comes to driving. I hope this helps, Mike!