04 Randomly Tries to Stall

[Saik]

So for a week now I noticed my 04 Explorer 4.0L. Randomly tries to stall while driving or idle. Basically the rpm randomly drops low, and revs back up and down as if it wants to stall. When I press on the gas pedal while this is happening it usually has a delay, or the explorer shuts off completely.

Weird thing is this happens randomly very rarely. Usually when I've been driving for atleast 4-5 hours straight.

The engine has been rebuilt since I had a timing chain failure a year ago, and is running pretty good. No codes pop up, throttle body is clean as a whistle, and EGR was also replaced during the rebuild.

However how do you clean the EGR? Could it be a IAC issue?

Update:

Car now throws a code, and the stalling is even WORSE than ever.

Code is P0193

Possible Fuel pressure problem, or problem with the sensor.
Car stalls when it's warm. Basically it starts surging before dieing out.

 

[Saik]

I removed the throttle body and cleaned it good, but I don't know where the IAC is or how to clean the EGR.

 

[Number4]

Check out this thread: Solved Stalling while at idle

Should be top post in forum, go to the last post by the OP.

Can't paste a link via my iPhone because Apple sucks.

 

[Saik]

Update:

Car now throws a code, and the stalling is even WORSE than ever.

Code is P0193

Possible Fuel pressure problem, or problem with the sensor.
Car stalls when it's warm. Basically it starts surging before dieing out.

 

[boominXplorer]

Either the sensor has gone completely bad or it has come loose. It should be on the drivers side fuel rail towards the front. I am not sure if you can see it with the intake manifold installed though.

If you have access to a scanner that can view PIDS then you can see what value the fuel rail pressure sensor is showing and see if its realistic. If it shows different values at different RPM then it is reading correctly and you might have a fuel pump issue.

 

[Saik]

Okay so what I did was remove the intake manifold (First time doing it) and basically just cleaned the fuel rail area, and removed the fuel pressure sensor and just brake cleaned the connectors and the sensor itself.

Car no longer stalls, no more CEL, or fault codes . However I will still replace the sensor, as what I did may only be a temporary fix.

While I was at it, I cleaned the intake manifold, EGR, throttlebody, and PCV. Car seems to run smoother.

 

[boominXplorer]

I have seen someone do valve cover gaskets, cleaned everything down with brake parts cleaner and had multiple misfires on restart. What had happened was oil residue got in the plugs for the injectors and wasn't letting it have a good connection. The intake was pulled back off, connectors cleaned and reinstalled and it ran perfect after. A situation like this can happen to the most skilled mechanic, you just have to take your time and make sure all the junk you rinse off doesn't make it to any open plugs.

 

[Saik]

It seems my sensor is bad. The sensor went bad again and CEL came on. P0193. It was off for a good while when I cleaned the sensor, looks like I need to replace it

 

[Number4]

Brake cleaner is caustic to plastic. You'd be better off using throttle body cleaner, but even then...