2001 Ford Edge rough idle

Without a check engine light, it becomes a guessing game. I would start by checking for vacuum leaks first. Also, check the EGR valve to make sure it isn't carboned and not working properly. As far as the carbon on the valves, that isn't going to cause this problem. Can you tell me what has been replaced?

Let me know.
Joe

If you start the engine, you may actually hear a hissing from a vacuum leak. Some mechanics will spray starting fluid on them. If there is a leak, the RPM's will go up. I hate doing it that way. Although it works, if the starting fluid hits something hot enough, it can catch fire.

I would also recommend checking the make sure the fuel pressure regulator is working properly. Here is a how to for checking it.

https://www.2carpros.com/how_to/how_to_check_fuel_pressure.htm

The video discusses fuel pressure and also how to check if the regulator is working.

Let me know what you find and thanks for using 2carpros.com.

Joe

I just checked the pressure reqirements. According to Mitchell online it can range from 30 to 65PSI which is really a big range. I have to confirm something with you. The pressure I just mentioned is for a 2001 ford ranger. In your original posting, you listed the vehicle as a 2001 ford edge. Since they didn't offer the edge in 2001, I have been basing this on a ranger. If I am wrong, let me know.

Now, the manual says the max pressure is 65PSI with the engine running. However, when you disconnected the regulator, you said there was no change. When you disconnect the fuel pressure regulator, the pressure should go up about 5 or 10 PSI. If it doesn't the regulator is bad. Also, when you were checking it with the engine running, did the pressure increase when you hit the throttle? Also, was there any evidence of fuel in the vacuum hose going to the regulator?

Let me know.

Joe

Based on your description, I think the regulator is bad. When you remove the vacuum from it, the pressure should go up 5 to 10 PSI.