QuestionQUESTION: I have a 2001 Tiburon that bogs and stalls and puffs out black smoke when trying to increase the gas pedal..it idles fine..there are no trouble codes, MAF, TPS are checked fine and no vacuum leaks.
Also fuel pressure is checked inline while car is running and is showing excellent fuel pressure with no drop out.plugs, wires and even coil pack all changed but still same thing...any ideas at all would help..has local Hyundai techs scratching their heads.
ANSWER: Could be a number of issues. I'm assuming the check engine lamp isn't on and that there are no trouble codes stored-- that would probably make this a simple issue to diagnose.
Since the plugs/wires/coil were changed, can you tell me if there's a misfire issue? If so, it'll be important to check compression and perhaps determine if there's a faulty injector.
Presuming you're not misfiring, I'd start with looking for two potential causes:
-- Faulty oxygen sensor. A defective oxygen sensor can cause the mixture to be too rich, causing the black smoke you describe.
-- Bad fuel. I've only seen this once, and it was a bear to figure out-- mostly because we've been taught from experience that this is almost never the issue. After checking and doublechecking nearly everything, I attached a pressure canister with good fuel to the fuel rail and verified the car ran better.
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QUESTION: There is no misfire or codes..engine idles very smooth..just when the gas peddle is depressed down that it starts to bog almost like running out of fuel..its why they placed an inline fuel monitor on the rail but pressure is good..the more you press down the worst it gets till it stalls after belching black smoke
AnswerI'd recommend checking the two things I have already mentioned-- the oxygen sensor and the fuel itself.
Depending on the amount of smoke, you might check for a clogged catalytic converter. This isn't typically consistent with the black smoke, but its consistent with the other symptoms as you describe them.
