Announcement

Collapse
No announcement yet.

Runs better when its low on gas

Collapse
X
Collapse
 
  • Page of 1
  • Filter
  • Time
  • Show
Clear All
new posts
Previous template Next
    #1

    Runs better when its low on gas

    Ever since my car has been forced to run on this ethanol mix shit, it just runs poorly. I ran over the weekend with about a quarter of a tank and it drove like a new car. Engine idled smooth, shifted smooth (didn't even hear or notice it shifting), and had plenty of power.

    I drove it today after I put a full tank of gas in it yesterday and it ran very poorly. It doesn't matter what grade I use, and I didn't run it lower than a quarter of a tank. If I fill it up with 89 or 93, it misses at low rpms, shudders, lacks alot of power (20 second to get to 0-60), and doesn't shift properly. It chugs (sounds like a bad miss) from 15 up to 35mph. It also cuts in and out of idle when moving in traffic at low speeds. This seems to happen everytime I put gas in this car.

    I can't scan for codes though since I can't interpret the codes from the actron code scanner I have. For my truck, it interpreted(example:4 flashes= 02 sensor lean condition) the codes in the haynes manual, but it doesn't have code interpretations in the haynes manual I have for the merc. Would a chilton's manual have the code interpretations that I need?

    I know the low speed idle problems are probably the TPS, but I doubt it could have that much of an effect on anything else. It does the idle surging problem sometimes on a hot humid day or night.
    Current rides - 1991 Ford Thunderbird 3.8 v6 (gas saver/DD) - New Heads/Headgaskets with ARP studs, Air Silencer Delete, 70mm MAF, Plasti-dipped Matte Black with a Silver Metalflake Overlay, Muffler Delete, some LED's, 30.233 MPG for high MPG average!
    2006 Jeep Wrangler 4WD (fun vehicle/backup DD) - 4.0/6spd - too many mods to list.

    Associated Panthers:
    Father's 1994 Ford Crown Victoria - Stock, 45,000 miles.
    Sold in 2007 - 1987 Mercury Grand Marquis LS "Grandpa Special" 2 door.
    http://www.cardomain.com/ride/2128327
    Tags: None
    #2
    Ford EEC IV codes are all the same really, see the list here: http://www.grandmarq.net/vb/showthread.php?t=39


    No idea why it would run better on a low tank. Makes little sense to me. It might be a faulty temperature sensor causing the idle problems. Try pulling the intake temp sensor and cleaning it up. The ends tend to get all gooped up over the years. Its located on the driver's side just behind the #5 injector.

    86 Lincoln Town Car (Galactica).
    5.0 HO, CompCams XE258,Scorpion 1.72 roller rockers, 3.55 K code rear, tow package, BHPerformance ported E7 heads, Tmoss Explorer intake, 65mm throttle body, Hedman 1 5/8" headers, 2.5" dual exhaust, ASP underdrive pulley

    91 Lincoln Mark VII LSC grandpa spec white and cranberry

    1984 Lincoln Continental TurboDiesel - rolls coal

    Originally posted by phayzer5
    I drive a Lincoln. I can't be bothered to shift like the peasants and rabble rousers

    Comment

      #3
      All the ford codes are the same...

      Might be a fuel pump or filter issue.
      Builder/Owner of Badass Panther Wagons

      Busy maintaining a fleet of Fords

      Comment

        #4
        Not sure if its the fuel pump, but it is probably original and the gas mileage varies alot. Plugs looked ok, but its running a little lean on the passenger side. The passenger side cylinder head has a valve tap though. Somedays I will only get 10-12mpg in the city, 14mpg on the highway under light driving. Other days I can get 16mpg in the city and 22mpg on the highway, even with a slight wheel vibration.

        I haven't replaced the fuel filter on this car, but I don't know how much of a difference it would make.
        Current rides - 1991 Ford Thunderbird 3.8 v6 (gas saver/DD) - New Heads/Headgaskets with ARP studs, Air Silencer Delete, 70mm MAF, Plasti-dipped Matte Black with a Silver Metalflake Overlay, Muffler Delete, some LED's, 30.233 MPG for high MPG average!
        2006 Jeep Wrangler 4WD (fun vehicle/backup DD) - 4.0/6spd - too many mods to list.

        Associated Panthers:
        Father's 1994 Ford Crown Victoria - Stock, 45,000 miles.
        Sold in 2007 - 1987 Mercury Grand Marquis LS "Grandpa Special" 2 door.
        http://www.cardomain.com/ride/2128327

        Comment

          #5
          Uh, prolly a huge difference. I would suggest doing it. It's cheap, and I'm sure it needs it.
          Builder/Owner of Badass Panther Wagons

          Busy maintaining a fleet of Fords

          Comment

            #6
            Fuel filters are a 10 - 20K mile item. Time to replace it bucko fork up the $7.50.
            2004 Marauder M79 90K miles Jmod!! 14.85 @95.63
            2004 Crown Vic LX 135K Silver Birch Light flint leather FMX1 04 P-71 PCM swap 04 P-71 Airbox and Zip tube "$100 MZT" 01 F-250 70 MM TB 21mm swaybar wood steering wheel BH headlight relay

            Comment

              #7
              I'll try replacing the fuel filter, there is just the one filter under the car right? Also, the fuel pressure I'll check the IAT sensor, it makes sense for some of the driveability issues I've been having. Still doesn't make sense why it runs better with less gas, but it could just be the fuel filter or pump getting worse.
              Current rides - 1991 Ford Thunderbird 3.8 v6 (gas saver/DD) - New Heads/Headgaskets with ARP studs, Air Silencer Delete, 70mm MAF, Plasti-dipped Matte Black with a Silver Metalflake Overlay, Muffler Delete, some LED's, 30.233 MPG for high MPG average!
              2006 Jeep Wrangler 4WD (fun vehicle/backup DD) - 4.0/6spd - too many mods to list.

              Associated Panthers:
              Father's 1994 Ford Crown Victoria - Stock, 45,000 miles.
              Sold in 2007 - 1987 Mercury Grand Marquis LS "Grandpa Special" 2 door.
              http://www.cardomain.com/ride/2128327

              Comment

                #8
                Yep, one filter, passenger side mounted on the frame rail forward of the tire. Two 5/16" head screws to remove the plastiic cover, two plastic clips to hold the lines on. Just be careful you don't get a face full of gas. I pop the inertia switch in the trunk and start the car so it bleeds off the fuel pressure, or if you do it in the morning after letting the car sit overnight it should be fine. Just be careful to not get gas in your face, it burns.
                86 Lincoln Town Car (Galactica).
                5.0 HO, CompCams XE258,Scorpion 1.72 roller rockers, 3.55 K code rear, tow package, BHPerformance ported E7 heads, Tmoss Explorer intake, 65mm throttle body, Hedman 1 5/8" headers, 2.5" dual exhaust, ASP underdrive pulley

                91 Lincoln Mark VII LSC grandpa spec white and cranberry

                1984 Lincoln Continental TurboDiesel - rolls coal

                Originally posted by phayzer5
                I drive a Lincoln. I can't be bothered to shift like the peasants and rabble rousers

                Comment

                  #9
                  It might be a bigger fuel problem than I thought. I drove home from college today and it shuddered at different rpm ranges, even on the highway at certain times. Didn't have much power either and the engine was idling a little high along with alot of noise. As soon as I hit a half of tank though when I pulled into Philadelphia, it started to run better and quieter with a little extra power. However, I rolled down the windows and noticed that there was a very strong gasoline smell for a good 5 minutes after I floored it to merge onto a 50mph road (car was loaded down with alot of stuff). Didn't break 15.5mpg the entire trip with easy driving in OD on route 309.

                  I'm going to check tommorow for fuel leaks and pull the plugs. Seems like its probably one or more bad injectors.
                  Current rides - 1991 Ford Thunderbird 3.8 v6 (gas saver/DD) - New Heads/Headgaskets with ARP studs, Air Silencer Delete, 70mm MAF, Plasti-dipped Matte Black with a Silver Metalflake Overlay, Muffler Delete, some LED's, 30.233 MPG for high MPG average!
                  2006 Jeep Wrangler 4WD (fun vehicle/backup DD) - 4.0/6spd - too many mods to list.

                  Associated Panthers:
                  Father's 1994 Ford Crown Victoria - Stock, 45,000 miles.
                  Sold in 2007 - 1987 Mercury Grand Marquis LS "Grandpa Special" 2 door.
                  http://www.cardomain.com/ride/2128327

                  Comment

                    #10
                    If the fuel pressure is low, it'll run like crap. Get a new filter in there and fun a bunch of injector cleaner... If it's the injectors I have a few stock 14lbers that I'll give you-just pay shipping.
                    Builder/Owner of Badass Panther Wagons

                    Busy maintaining a fleet of Fords

                    Comment

                    Previous template Next
                    Working...
                    X