It can be eithier plug wires crossed or burned valves. Have it checked out.
It might be on the firewall under the hood on the left side.BEst of luck....I to am haveing trouble with astro van.
CHECK your tioming - might have jumped a tooth - check control module or coil might be the problem
You might have a blown headgasket on top
A motorcycle jerk or backfire can come from the choke not shutting off completely, the fuel jets might be clogged, a gasket or seal may be broken. Valves that are out of adjustment could also be the problem.
A rototiller may backfire when it is starting because the valves need to be adjusted. Another reason that it might backfire is because you have to replace the spark plug.
might be the thermostat stuck shut The radiator and cooling system could be low on coolant
Go to Auto Zone and have the computer codes read for free.
It might be overfueled but it also might be just that when you turn the key off the motor runs on a bit and puts fuel into the hot exhaust and it ignites it and makes it backfire.
There are a couple of things that might cause a Chevy Tahoe to lurch forward after releasing the brake. One reason could be that the idle is high. The drive shaft may have to be greased.
Plug might be cracked .And might be arching
it probley needs a new battery or a new gas pedal. Another reason is the car might be to old