Does 2000 Mercury Mountaneer have a Factory Fuel Return Line

[donalds]

Next time you fill up and it’s super hot dump a 1/2 cup of marvel mystery oil into your gas. If your actually vapor locking, which I highly doubt, this will band aid it.

That's some good stuff for any engine any size

 

[2000StreetRod]

If you have a scanner it is very easy to read the engine coolant temperature PID. If the reading is cool when the ambient temperature is hot the PCM will cause a rich condition making engine start and idle unreliable.

 

[EXFAN]

I’m curious if your fuel mileage is less than it should be? If yes and with your symptoms, most likely the CTS. Too rich for the warm engine to start when temps get over 100 degrees. Plus the engine gets hotter for a short period after the engine is shut off. Previous posts to check PID data are spot on.

 

[Summajet]

I have a 2000 Mercury Mountaneer (same as Ford Explorer) with a vapor-lock issue and would like to know if this model has an existing Factory Return gasline.

I have a 2000 mountaineer also. I would do these things Below,

Check fuel pressure (on fuel rail middle top of motor passengers side.)
Replaced fuel filter? Under drivers side inside frame rail. Depressurize the fuel system and then using the better fuel line disconeects remove the filter. Keep it level and place a clean white paper towel and tilt old filter with end towards rear of truck down. See what comes out of the filter.
I had replaced my fuel pump as it was averaging 45psi, hesitation and slower to start/run. It would also cut off at times. Biggest thing I feel caused fuel pump to fail is there is a rubber hose that slides into the fuel pump. It had a kink/restriction in it from ethanol usage and would restrict the fuel. I had to get a good replacement from the junk yard. If you remove the fuel pump make sure to get at least two rubber Hoses. I had about 1/2 gas left in mine when I replaced the pump. I used a floor jack and straps. Make sure you do this under an open carport or shade. Do not do it in an enclosed garage as it is gas and result from tool dropping on metal would be catastrophic.

 

[BenDT]

I have a 2000 Mercury Mountaneer (same as Ford Explorer) with a vapor-lock issue and would like to know if this model has an existing Factory Return gasline.

Had a similar issue. Was thinking all sorts of stuff from fuel pump overheating, vapor lock, injector heat soaked even. Tried many methods to test. From fuel pressure, to general wiring movement, scanner seemed to check out for the most part. I found one day that if I played with my a/c (on/off/on/off) in direct sun parked in a hot lot that my idle would start to act funny. I then decided when I felt the idle “missing/not firing” to floor it WOT. I heard what sounded like a engine with fuel cut dying. So I then decided to do the old sensor checksaroos. The cam was good had old good sensor, my tps was older so I did replace under warranty (yes I went box store for that one) and then I decided to check my crank sensor. I never had changed this and remembered these exact issues with my jeep when the crank sensor acted up. Changed the crank sensor, and I’m sure I picked back up 15% power, and it’s very noticeable in mid pedal range. My mpg actually went up by almost half a gallon. Something I did notice was my idle speed in drive was pretty high before changing tho I did not check speed or rpm. When I changed it my trans will take 10 seconds or so to actually get speed going get to moving (250k hard miles on trans so May not be correct info for a true test, just my 2 cents) before it was almost immediate from the higher rpm. Good luck buddy

 

[BenDT]

I’m curious if your fuel mileage is less than it should be? If yes and with your symptoms, most likely the CTS. Too rich for the warm engine to start when temps get over 100 degrees. Plus the engine gets hotter for a short period after the engine is shut off. Previous posts to check PID data are spot on.

Just curious if he could simply unplug sensor to test. Open loop I’d assume, but shouldn’t be running super rough and should start. Easy test if so, tight spot but could get it without any involved disassembly

 

[Andymoejoe]

I have a 2000 mountaineer also. I would do these things Below,

Check fuel pressure (on fuel rail middle top of motor passengers side.)
Replaced fuel filter? Under drivers side inside frame rail. Depressurize the fuel system and then using the better fuel line disconeects remove the filter. Keep it level and place a clean white paper towel and tilt old filter with end towards rear of truck down. See what comes out of the filter.
I had replaced my fuel pump as it was averaging 45psi, hesitation and slower to start/run. It would also cut off at times. Biggest thing I feel caused fuel pump to fail is there is a rubber hose that slides into the fuel pump. It had a kink/restriction in it from ethanol usage and would restrict the fuel. I had to get a good replacement from the junk yard. If you remove the fuel pump make sure to get at least two rubber Hoses. I had about 1/2 gas left in mine when I replaced the pump. I used a floor jack and straps. Make sure you do this under an open carport or shade. Do not do it in an enclosed garage as it is gas and result from tool dropping on metal would be catastrophic.

The easiest way to tell is by the back drivers side of truck next to the spare tire is there a square box with 2 fuel lines and electrical wires running to it ? If there is than no there is no return line... be sure if you put any hoses on your fuel line they are hi presure injector li es

That's some good stuff for any engine any size

Also the fuel pu.p will only have 1 tube coming out the top. A ford e xplorer will have 2 tubes. The one with 2 tubes can be used just make sure which is your output tube the other you simply plug it.

 

[Andymoejoe]

The easiest way to tell is by the back drivers side of truck next to the spare tire is there a square box with 2 fuel lines and electrical wires running to it ? If there is than no there is no return line... be sure if you put any hoses on your fuel line they are hi presure injector li es

Also the fuel pu.p will only have 1 tube coming out the top. A ford e xplorer will have 2 tubes. The one with 2 tubes can be used just make sure which is your output tube the other you simply plug it.

By all means do not attach output to the canister (box next to spare tire) this will cause a dangerous situation and fuel to go every where. The canister should attach to a green plug seperate from the pump keep in mind that green thing is plastic molded into the tank breaking it means go buy a new tank.

 

[Mbrooks420]

The 2000 will be returnless.

 

[imp]

I have a 2000 Mercury Mountaneer (same as Ford Explorer) with a vapor-lock issue and would like to know if this model has an existing Factory Return gasline.

Best way to tell is to LOOK and see if there are TWO fuel lines existing between the fuel tank and the engine.

Vapor lock occurs when fuel BOILS inside the confines of the fuel delivery system. This was a problem encountered with carburetted engines but is NON-EXISTENT with EFI fuel systems since they operate at much higher fuel pressure than carburetors (40 to 60 psi vs 4-6 psi).

 

[CDW6212R]

All 1999 and newer Fords have a returnless fuel system, there is no return line. The pressure on all 99+ Fords must be above 60psi normally, 55psi is low.

If you have any kind of engine rough running issues after checking spark plugs etc, check the fuel pressure. In any EFI vehicle, lower than normal pressure will create all of the symptoms mentioned in this thread. Be sure the basic items are checked before seeing a car dealer etc, the tune up items and the fuel pressure.