Another is it the fuel pump thread

[mracer]

My car is a 2004 A4 3.0 Q6 with 90,000 miles. A while ago I had the humming fuel filter but that stopped. But lately my car will die on me if the engine is up to temperature and I'm sitting at a red light. It will crank and crank before it re-fires. It starts up fine cold but if the car is up to temperature, I don't hear the fuel pump prime and it's hard to start. Also while I'm driving it will stumble and then the rpms go into a safe mode where they will not go above 4,000 rpms and won't go below 1,000 at idle. It actually bounces the rpms at idle. My question is, do you think it is the fuel pump? Would the temperature of the car affect the fuel pump or do you think it might be the relay or the crank position sensor? I don't have any VAG scanner so I'm just trying to get ideas of what it might be. The CEL is on and sometimes on restart the EPC light comes on.

[blackfc3s]

It could be a couple things.
Cps is likely the culprit. They like to fail in high heat environments.
When have you changed your fuel filter? Change the fuel filter before the pump.
Got any vacuum leaks?

Besides that, scan the car and get back to us.

[mracer]

I just went to Autozone and had them scan the car and it gave me P0321, P0322 Faulty CKP Sensor so it looks like I will be replacing the crank sensor. I will change the fuel filter soon just for good maintenance.

[AvantinUSP]

definitely change the fuel filter if you had the humming noise. any procrastination is eventually gonna kill your pump.

[J-jizzle]

Don't run your car on low gas all the time (gas keeps the pump cool) and replace the filter ever 30k. 2 things I did not keep up with. But I do now.

[J-jizzle]

Sounds like my car when my fuel pump went out. Pump will work fine when cold and craps out when it gets hot. Mine went out close to the same milage. I replaced mine across the street from the dealer.haha I had a hard time staying up to speed on the interstate and the car would die trying to leave lights. The problem happened fast and I fixed it that day on the way back from Maryland. I payed 375 for a new assembly at the dealer.