Question

Which of the following should be performed first when checking an engine that produces black smoke under load?

a) Injection timing
b) Air filter restriction test
c) Fuel quality by chemical lab analysis
d) Plugged DPF

Answer 1

The first step is to perform the air filter restriction test. After that, check the injection timing. The last step, if needed, is to check for a plugged DPF.

Step-by-step explanation:

The first step to take when checking an engine that produces black smoke under load is to perform the air filter restriction test. A clogged or dirty air filter can restrict the flow of air into the engine, causing incomplete combustion and black smoke. By checking the air filter for restriction, you can determine if it needs to be cleaned or replaced.

After performing the air filter restriction test, the next step is to check the injection timing. Incorrect injection timing can lead to poor fuel combustion and black smoke. This can be adjusted by a qualified technician.

The last step, if necessary, would be to check for a plugged DPF (Diesel Particulate Filter). A plugged DPF can cause exhaust flow restriction and lead to black smoke. If the engine has a DPF, it should be inspected and cleaned or replaced if necessary.