Possible Fuel Pressure Regulator Issues??

[bsarles]

Hello,

I have an 2002 Explorer Sport 4.0 SOHC with 191,000 on it.
I am having some issues that you guys might be able to help me.

Suddenly my gas mileage dropped to about 8 mpg for that last week and I am not getting an engine light code at all.

I have been getting a rotten egg smell too.
Fuel pump gets loud when i put the ignition into ACC right before it cranks.
O2 sensors have been replaced a little while ago.
When i fist got the truck at 110,000 it would start right up and now take a few seconds to get going but not more then 3 seconds.
While driving up a good hill the engine would start clanking not real bad but almost like a spark knock.
Truck still drives with no stalling or stumbling although when you put it in park it makes a clunk but no stalling. I did replace the IACV 5 k ago because it used to just die when you put it in park.

Please let me know what you think and by chance were in the world is the fuel pressure regulator at on this truck?

How can I diagnose it old school, can i pull a vacuum hose and wait until fuel pops out like some other cars due to a leaky diaphragm?

 

[blueoval9erlifer]

How long since you replaced the fuel filter? if its getting clogged then the fuel pump will have to work harder to get the fuel past it. also the rotten egg smell im not sure of but have you lost power? if so get a digital thermometer and go drive it down the highway 8 to 10 miles and check the front and back of the cats see if they are plugged.

 

[bsarles]

never changed the fuel filter.... should do that but the rotten egg smell and bad gas mileage with no O2 codes? if the filter was clogged up then why would it be dumping fuel into the engine at an alarming rate?

Just being a little dumb here but could a clogged fuel filter cause bad gas mileage and rotten egg smell?

 

[blueoval9erlifer]

probably not but could be causing your fuel pump to be overworked, ( i think) im no professional just a shade tree farm kid mechanic, which would possibly cause it to make more noise. the only reason i mentioned your cats is because on my f150 work truck it started to loose gas mileage had a bad smell and lost power and they were clogged up replaced them and alls back to normal

 

[bsarles]

Looks like i will replace the fuel filter anyways but on a side note how do i test for the fuel pressure regulator... there has to be a reason why im dumping gas into the engine to get 8 mpg without an error code. the rotten egg smell could still be due to the dumping of fuel and the cats doing their job to much.

Anyone else have suggestions?

Just an update: i did do a hot test meaning i ran around the neighborhood until the engine got good and hot and the egg smell did go away. smell like damp exhaust kinda musty. I think my CATS are still good.

I'm still leaning toward the fuel issue. Why is it dumping fuel with no codes? FPR?? if so how do i check and were is the regulator located?

 

[bsarles]

just a thought.... If the fuel filter is bad could that cause the fuel pressure regulator to flood the engine maybe like over compensating for a restricted fuel filter?

Update: The engine seems to still have power when trolling around town. i'm not seeing any serious sluggishness or the such. I am just having bad gas mileage. This is driving me freaking nuts!!