1999 Explorer XLS 4L SOHC

[matthfam]

Hi all.
As a new member I am not very "forum literate" if I can use that term. I am having trouble finding information on my 'sploder as to the fuel pressure regulator. Some say that the 4L SOHC has the regulator incorporated in the fuel sender pump. Others say that there is a model that is a non-return fuel system and has no regulator but some system on the heads that regulate the fuel. I don't know where to find this. Also my "check engine" light does not come on when the gas cap is removed. Can anyone enlighten me??? (BTW it is a 1999 Explorer XLS model)
-very confused!

 

[2000StreetRod]

returnless fuel system

The 1999 and later Explorers have a returnless fuel system with the fuel pressure regulator in the fuel tank and a fuel pressure damper on the fuel rail. See What's that on the fuel rail?

 

[matthfam]

Thanks. I will have to look for the "fuel rail"

 

[2000StreetRod]

fuel pressure

There is a Schrader valve (looks like a tube valve) on the fuel rail. The fuel pressure on the rail should be about 65 psi any time the engine is running.

 

[matthfam]

Thanks for your assistance. One more question... I haven't tested the pressure yet but what would indicate I need to replace the FPR, low pressure or high pressure? Or either?
I am only getting 15 mpg Canadian gallon (or 12.4 mpg US gallon), so something is wrong.

 

[2000StreetRod]

low fuel pressure

The intank fuel pressure regulator is normally much more reliable than the intank fuel pump. The typical fuel pressure problem is low fuel pressure.

Is the check engine indicator illuminated? If so, I suggest that you read the diagnostic trouble codes (DTCs).

On my 2000 Sport there is a Check Fuel Cap indicator separate from the Check Engine indicator. I think your 1999 should have one also. It is located between the Check Engine indicator and the Safety Belt indicator.

 

[matthfam]

Problem is that the 'check engine' light does not come on when the gas cap is removed. So, no, the light does not come on except when vehicle first started but goes off like it should. The only thing that tells me something's wrong is the gas mileage....

 

[2000StreetRod]

Check Fuel Cap indicator?

. . . On my 2000 Sport there is a Check Fuel Cap indicator separate from the Check Engine indicator. I think your 1999 should have one also. It is located between the Check Engine indicator and the Safety Belt indicator.

Did you look at your Owner's Guide to see if there is a Check Fuel Cap indicator? I doubt that the indicator is related to your poor fuel economy. Is everything stock on your vehicle? Do you happen to have oversize tires?

 

[matthfam]

There is a 'Fuel Door' notation next to the 'check engine' light but it does not light up even when the cap is removed. (blown fuse) or is there a light at all as there seems only to be the wording...
The manual doesn't mention it at all..
But would a non-return fuel system have a pressurized system?? doesn't seem it should...

 

[mikepier]

My memory is foggy, but I thought the XLS models only came with the OHV V6 that year. You sure you don't have an XLT with the SOHC?

 

[2000StreetRod]

testing indicators

All of the indicators should illuminate when the ignition is switched to Run. When Ford deleted the variable induction system in 1999 they used the VIS PCM pin for fuel cap monitor. You may have an early model without the wiring change.

As I previously stated the fuel pressure at the rail is a constant 65 psi when the engine is running. The FPR is in the fuel tank so excess from the fuel pump goes directly to the tank.

The corrugated hose in the photos is the return to the tank from the FPR. A returnless system reduces fuel temperature and emissions.

 

[matthfam]

The engine says "4 L SOHC" and the emblem on the side says "XLS"

 

[mikepier]

The engine says "4 L SOHC" and the emblem on the side says "XLS"

I just checked my 99 brochure book which I still have when I bought my 99 XLT.

For the XLS, the SOHC was only available on fleet vehicles. So I'm guessing at some point your truck was part of a fleet of trucks for a company of some sort.

But for a regular XLS, only the OHV was offered.

 

[matthfam]

Good to know....

 

[matthfam]

Very odd... I changed the air filter and got 6 mpg better on the same route as before. I wonder what I'll get if I do some more tuneups...

 

['99_Limited]

I just checked my 99 brochure book which I still have when I bought my 99 XLT.

For the XLS, the SOHC was only available on fleet vehicles. So I'm guessing at some point your truck was part of a fleet of trucks for a company of some sort.

But for a regular XLS, only the OHV was offered.

I have a 1999 limited manufacture date 1/99 with the "E" in the VIN which has the 4.0L SOHC

 

[matthfam]

But yours is an XLT, right? Mine is an XLS with 4 L SOHC.

 

[swshawaii]

Enter VIN. Also click "minor features to expand this list".
https://www.etis.ford.com/vehicleRegSelector.do