2004 mazda 6 starts runs then shuts down
 

Hi,, my 04 mazda 6 starts runs at normal idle then it wants to conk out so I have to rev the engine to 2000 rpm to keep the engine going and then when the engine is at normal temperature I release the gas pedal the engine conks out and then I try to restart it it doesn't start?? I basically have to wait overnight to make sure the engine is cold otherwise it wont start when its hot. When the engine is cold I have to pump the gas in order to get it started..any ideas would be greatly appreciated.


Thanks

Taz: how many miles on the car? Is the CEL light on? have you done any work to it?

At first thought it could be a major vacuum leak.

HI.the car has 204,000 kms and done only oil changes since i purchased the vehicle from another person 2 years ago. Im not sure if the CEL light came on.. i drained the oil to do another oil change but i did read the manual to make sure cap was on tight etc..but why wont it run when it gets to normal temperature.thanks for reply

I forgot to ask: which engine is in your 6? 4 cylinder or 6 cylinder?

There are a many possible reasons why your engine does not run when warm. But let me point to your car's history:
200 000 km, at least 2 years of no maintenance other than oil changes. Good job doing the oil changes!
Now: replace the air filter, replace the spark plugs, clean the MAF sensor with MAF sensor cleaner and the throttle body with Throttle Body Cleaner (I prefer CRC products).
Check for vacuum leaks. Go to Youtube to see several methods. Vacuum leaks will make the engine run lean because significant amounts of air by pass the MAF sensor and and the computer injects to little fuel. When warm the computer uses the sensor data to figure out the amount of fuel. When cold it uses built in data.

In short: do the regular tune-up first. It may solve the problems completely. If it does not then we have eliminated some common causes and take it from there.

Hi..the mazda is a 6 cylinder..i did clean maf sensor and i was going to clean the throttle body next..i will do what you are recommending, i will also post the results after i try everything that you said.
thanks again