Try this, search the internet for cleaning the fuel injection system,
including cleaning fuel injectors, throttle body and intake valve, to find fuel system problem that fits your situation!!
iv tried everything to fix my jeep. iv replaced all the fuel injecters, replaced the whole distributer and plugs and wires, including spark plugs and a brand new computer, everythime it starts jerking black smoke comes from my tail pipe and my gas milage goes low. what else can i try?

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