Jetta 2.5L Trouble Starting & Black Smoke

[Inferno19]

hey everyone,

about a year ago my car wouldnt turn on. got it checked and the MAF had to be replaced. ever since its been running fine. this afternoon i went to turn on my car and it had some troubles again. as i turned it on, it had difficulties fully starting as if turning on your lawn mower for the first time in spring. Eventually after about 3-5 seconds it ignited and the rpms were around 500 (even though the car hadn't been started in 12 hours). The check engine light came on and
it sounded like the engine was at a lack of oxygen. the exhaust was producing a black smoke as well. after about 20-30 seconds, the car turned off. i restarted it and it still had troubles but ended up staying on for a few minutes until i turned it off myself.

my battery still shows the green light lit up on it.
i only have 110,00 km on it and had an oil change at 108,000.

what could could be causing this?

[Inferno19]

bump

[_FUBAR_]

oem maf sensor?

[Inferno19]

even though i had it replaced a year ago?

[2001Jettagls]

Possibly Coolant temp sensor.
You need to get the codes.
If you do any of your own repairs, a scanner is a must.

[_FUBAR_]

was it replace with an oem maf sensor? if it wasnt an oem sensor then i bet its the sensor. oem sensors only.

[Inferno19]

unfortunately i dont have a scanner atm.
will look into the coolant sensor and oem maf.
thanks

[2001Jettagls]

Ay update on the problem?

[Inferno19]

still giving me troubles. mechanic cant figure out the exact problem.
he changed the spark plugs and flushed the engine as well as put an additive in the fuel tank.
still cant disgnose the problem.

[2001Jettagls]

If that's all he he did, then he didn't "diagnose" it properly.

With a hard start condition and the black smoke and the check engine light on, he should first retrieve the trouble codes. What were the codes stored in memory?

Next, hook up a scanner with "live data" capabilities. Turn the key on, and look at the coolant temperature. If the car is "overnight cold", the coolant temp should be close to the outside air temperature. If it is a significantly colder reading, that could cause the black smoke.

Next, start the car and watch the readings from the mass air flow sensor and the coolant temperature sensor. Are they normal readings?

If these check out ok, let us know and I'll give you more things to check out next.

[Inferno19]

will speak to him about these and let you know.
thanks !

[2001Jettagls]

Any update?

Did you ever get this fixed?

[Inferno19]

problem disappeared. never returned
thanks