The first things to check are the air intake, the fuel pump/filter and the governor.
fuel leak on top of what type of engine, gas or diesel?
An engine might sound like a diesel at operating temperature if the engine was a diesel or if there was an issue with the manifold. Sometimes gases escaping the manifold cover could cause the engine to sound different.
There are pages and pages of things that can cause a check engine light. You need to have it checked with a scantool. Then the code can be diagnosed and repaired.
I would recommend not running the engine until the fuel is drained. Any amount of petrol/gasoline in a diesel can cause engine or fuel system damage.
Any number of things could cause your vehicle to surge. You need to take your vehicle to a tune-up shop and have it diagnosed.
The RPMs and the engine of the 2001 Oldsmobile Alero might surge if there is a problem with the oxygen or fuel sensor. It may also surge if there is a problem with the fuel injectors or the fuel filter.
BAD INJECTORS ON NEWER MODELS ????
change the fuel filter
Diesel fuel or coolant entering the crankcase. Either will cause serious engine damage. Stop driving the truck until you can have this repaired.
Absolutely not! Petrol (gasoline) can cause catastrophic damage to a diesel automobile engine, even in very small quantities.
yes...the lack of air would causes excessive fuel which would cause black smoke.
If it is a newer vehicle you are probably hitting the rev limiter. The computer will cause the engine to cut out when it reaches a certain RPM too quickly.