Why can't the throttle be increased when an off-road forklift is just starting up?

After the diesel engine of the off-road forklift is started, it should run at low speed for 3-5 minutes, for the following purposes: Warming up: Allow all parts of the machine to gradually and evenly rise to normal operating temperature, reducing wear and avoiding mechanical scoring. Ensuring lubrication: When the diesel engine of the off-road forklift is first started, the lubricating oil has high viscosity and poor lubrication in various parts; after warming up, the lubricating oil will gradually reach all lubrication points, preventing dry friction from damaging mating surfaces. After the diesel engine is started, the machine temperature is low, and the diesel fuel may not burn completely. If the throttle is increased and fuel supply is raised at this time, excess unburned diesel will form carbon deposits, worsening diesel engine emissions; in addition, excess diesel may flow along the cylinder walls into the crankcase, affecting cylinder wall lubrication, diluting the oil in the oil pan, reducing lubrication performance, and shortening the diesel engine's service life. During the handling operations of the four-wheel-drive off-road forklift, phenomena such as overloading, unbalanced swaying of loaded goods, and accidental falling of cargo may occur. Possible causes include: lifting too quickly during operation, or exceeding the specified speed during transport, with sudden braking to avoid obstacles causing cargo to fall; or the cargo not being properly secured to the vehicle body as required, or the cargo not matching the fork arm attachment of the four-wheel-drive off-road forklift, causing the cargo to detach from the fork frame. This risk can be completely resolved or largely avoided based on the following points: operate the four-wheel-drive off-road forklift as smoothly as possible; pack the cargo neatly and secure it tightly with the fork frame before transport; avoid sudden braking while driving; level uneven road sections in a timely manner; and at the same time, according to relevant regulations, cargo must not be overloaded. When the load on the fork frame is too heavy, it will cause the rear of the vehicle body to tilt upward. If a person stands at one end of the four-wheel-drive off-road forklift at this time, using body weight as a counterbalance, the rear of the vehicle body may suddenly lift upward when lifting the cargo, causing the person to fall. Such accidents may be caused by overloading of the four-wheel-drive off-road forklift, or by a lack of protective measures at the position where the person stands.