2000 Explorer shows lean in both banks

[BillRod]

Hi All

My son's 2000 Explorer (4.0, OHC, Auto) has been stalling very intermittently. Sometimes it might happen once or twice a week, sometimes you can drive it for hours up in the mountains etc before it might stall. Let it set a 1/2 hour and your good to go again for weeks or days before it happens again. Symptom is kinda like to old Vapor lock.

Took it to a shop and they found a stored code for lean on both banks.
They cleaned the MAF sensor and the code did not return.
They also suggested new plugs and wires.
I replaced the plugs and wires and it seems to be running better.

However the Check Engine light came back on.
I stopped by Autozone and their reader also showed lean in both banks.
I picked up a MAF sensor Cleaner spray can and I'm gonna try that again.

Any common Vacuum leak points on these?
Any other suggestions or things to look for?


Thanks
Bill

 

[aspevacek]

How old is the fuel filter and have you run any injector cleaner thru the system?

 

[adsm08]

The upper intake gaskets are probably more than due for replacement.

IIRC the upper intake "gaskets" on that year and engine is actually a single piece that will allow excess air to leak into both banks if it fails because the upper intake runs a line of 6 runners to split down the lower intake. That would be my first shot.


Not sure about the stalling. That is hard to go after without more info.

 

[deputy dawg]

Before you put a ton of money into it, replace the fuel relay switch, under the hood in the high currency fuse box. Also, don't just stop with one because there should be two of them. Look in the owners manuel, one will say (fuel) relay, should be #5 and the other will say (fuel , RAP module) should be #9 Depending what all you have in it.
To verify that was the problem, lay under truck, have someone cycle the ignition to on and listen to the speed of the fuel pump, Then change the relays and repeat... You should hear a faster hum from the pump, once you replace them. Clear the codes and drive