My car ran perfectly 2 days ago but when i started it today it started to vibrate like a 4cylinder engine. Black smoke comes out of the exhaust. The idle speed doesnt go down to normal rpm. I've tried starting it again after it had cooled down entirely, but the problem remains although it ran good until it tried to go back to idle speed.

Please help me if you know what could be wrong.

 

Check your plugs, oil, etc.. Maybe some bad gas.. Could be about anything.

When was the last time you opened it up and went WOT? You'd be surprised how getting on it and clearing out some of the carbon deposits can help the car smooth out.

 

What do u mean by WOT??

I forgot to mention that if i wait about 10 or more minutes it returns to normal idle speed and runs smoothly again.

 

WOT = Wide Open Throttle

So, basically, pedal to the metal.

Are you allowing the turbos to run for a few minutes before turning off the car?

 

Do you think it runs bad because there isn't enough radiator water so that the transmitter can't feel the temp.???

The last time it ran, i forgot to put on one of the radiator lids.

 

Check MAP sensor on Firewall. Little black box marked "boost sensor" to the left of the brake booster on the firewall. Should be a vacuum line connected to the bottom of it.

 

thanks i will try that although it seems strange that it could happen so suddenly, after my last run two days ago. I havent touched a thing since.

 

Sometimes the lines to the sensor can come loose. However, when it happened to me, it was a dramatic power lose. I don't know if that is the same symtom for everyone with that type of problem, if so, it's definitely not your problem.

You say there is "lots" of black smoke on startup? How long does the car smoke?

 

Tobias,

When ever you take the FD for a drive, be prepared to run the engine enough to at least get to operating temperature. Do not turn on the engine for 30 sec and then turn it off - you run the risk of flooding the engine. Like Mahjik said, once the engine is warm, make sure that you get into the upper RPM range. Also, do not boost for a couple of minutes (either by easy driving or turbo timer) before shutdown. I notice that if I follow these procedures, I get a lot less smoke on the next startup.

M

 

i've checked the sensor boost and it's ok.

I'm suspecting that it can be too little coolant because the the sensor that detects that the engine is cold shuts off too early. the sensor must think that the engine is warm. I'm asking where i should fill the coolant into cause there are 3 lids?