Announcement

Collapse
No announcement yet.

Fuel System Stalling/Hesitating/WTF?

Collapse
X
Collapse
 
  • Page of 3
  • Filter
  • Time
  • Show
Clear All
new posts
Previous 1 2 3 template Next
    #1

    Fuel System Stalling/Hesitating/WTF?

    Okay, so today after coming back from a 2 hour drive or so on a hot day, I found the engine stalling/spluttering/I dunno what was going on at about 50KPH.

    It was acting like there was intermittent fuel in the system as though I was about to run out of gas, only I'm not of course.

    This happened once before, when I found the air filter was dirty as can be. Only the engine would do this at about 20KPH instead of 50KPH and it would actually stall out on me.

    Putting it in Neutral and revving the engine produced black smoke from the exhaust.

    Can anyone help me pseudo-diagnose the problem? I suspect fuel pump/carbeurator?
    Tags: None
    #2
    How old is the fuel filter?
    sigpic


    - 1990 Ford LTD Crown Victoria P72 - the street boat - 5.0 liter EFI - Ported HO intake/TB, 90 TC shroud/overflow, Aero airbox/zip tube, Cobra camshaft, 19lb injectors, dual exhaust w/ Magnaflows, Cat/Smog & AC delete, 3G alternator, MOOG chassis parts & KYB cop shocks, 215/70r/15s on 95-97 Merc rims

    - 2007 Ford Escape XLT - soccer mom lifted station wagon - 3.0 Duratec, auto, rear converter delete w/ Magnaflow dual exhaust

    - 2008 Mercury Grand Marquis Ultimate Edition - Daily driver - 4.6 2 valve Mod motor, 4R75E, 2.73s. Bone stock

    Comment

      #3
      2nd that. Found my fuel filter had 65,000 miles and god knows how many years on it when I asked a similar question about lugging on the highway, uphill @>60mph.
      Might not be so simple, but, it's a $5 start and not a bad thing if you have no idea when it was last done.

      Btw, fram seems to have a bad reputation. I haven't examined various filters personally, but too many individuals are crying foul for it to be random slander-- so maybe pay $8 for a more premium non-fram fuel filter.

      ....though... I'm not sure that a clogged fuel filter would lead to black smoke....if anything the car should be running lean and not getting enough fuel? black smoke =oil or too much fuel.
      Last edited by BerniniCaCO3; 09-24-2011, 07:44 PM.

      Comment

        #4
        Have you changed the spark plugs because it can be that the fuel that is not burning burns after and produce black smoke. ONe thing it can be bad for the catalytic converter. Also oil produces blue smoke. Black smoke means running too rich. try the fuel filter and try the plugs and wire. Basically try doing a tuneup.
        1992 Mercury Grand Marquis.
        Upgrades: Big Brake Upgrade, digital dash, Custom ignition Switch system, sequential tail lights, Teflon Fuel lines, LED interior lights, rear end rebuild with limited slip.
        Future upgrades: 5.0 swap, 4r70w swap, aluminum driveshaft.
        sigpic

        Comment

          #5
          Originally posted by pivichot View Post
          Have you changed the spark plugs because it can be that the fuel that is not burning burns after and produce black smoke. ONe thing it can be bad for the catalytic converter. Also oil produces blue smoke. Black smoke means running too rich. try the fuel filter and try the plugs and wire. Basically try doing a tuneup.
          The plugs and wires were changed out a week ago.

          I suppose it could be the fuel filter, but why the black smoke?

          Comment

            #6
            black smoke is excess, unburnt fuel. blue smoke is oil... white smoke is coolant/water (IIRC)

            Bad plugs will leave a lot of unburnt fuel since the spark sucks. Also, injectors that are cloggy will not atomize well and give shit for burn too. Carbs that dump too much fuel will do the same thing.

            Only two things are infinite, the universe and human stupidity, and I'm not sure about the former. -- Albert Einstein
            rides: 93 Crown Vic LX (The Red Velvet Cake), 2000 Crown Vic base model (Sandy), 2003 Expedition (the vacation beast)

            Originally posted by gadget73
            ... and it should all work like magic and unicorns and stuff.

            Originally posted by dmccaig
            Overhead, some poor bastards are flying in airplanes.

            Comment

              #7
              slightly too much fuel shows up grey, but it will burn your eyes and nose. Vacuum leaks will make the carb do stupid things too. You won't get proper airflow across the venturies and the fuel may not atomize properly. Or there could be something wrong in the carb that makes it just dump fuel down the throat. I've seen sticky floats or leaky needle seats cause this problem.
              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

                #8
                So if I replace the fuel filter and carbeurator I should have this problem eliminated then, correct?

                Comment

                  #9
                  replacing the carburetor would be a bit drastic at this point. It'll run you 200+ for a rebuilt carb.

                  This is a stock variable venturi carb, right? If so, your fuel filter is on the carb, right where the fuel line goes in on the front. It generally won't go "bad" in a way that messes up the operation of the car like a fuel injected car's filter will, though it's still a good idea to replace it.

                  85 4 door 351 Civi Crown Victoria - Summer daily driver, sleeper in the making, and wildly inappropriate autocross machine
                  160KMs 600cfm holley, shorty headers, 2.5" catted exhaust, 255/295 tires, cop shocks, cop swaybars, underdrive pulley, 2.73L gears.
                  waiting for install: 3.27's, Poly bushings, boxed rear arms, 2500 stall converter, ported e7's, etc

                  06 Mazda 3 hatch 2.3L 5AT (winter beater that cost more than my summer car)

                  Comment

                    #10
                    Okay, so...

                    The symptoms I'm describing...is that indicative of a faulty fuel filter? Or is the carbeurator damaged?

                    I'm asking so I can budget for necessary repairs (today).


                    Thanks for the replies, by the way.

                    Comment

                      #11
                      How do your spark plugs look? For the longest time I had one of my carbs calibrated too lean and was trying to make up forthe off-idle stumble with an excessively rich idle. Funny thing, the plugs kept getting all black and fouled and then it'd idle even weirder. Constantly stunk like stink too, of course.


                      What's the condition of the rest of the fuel and ignition systems?
                      2012 Mazda5 Touring | Finally working on the LTD again!

                      Comment

                        #12
                        I had a similar problem on a 1987 ford crown vic. It turned out to be dirty injectors. I took it to a shop, the mechanic hooked it up to a "cleaner". He said it took about 45 minutes IIRC to clean the injectors. After that WOW. Big difference. I don't remember the machine name, but it hooks into your fuel rail IIRC and just blows/dissolves/cleans the dirt out of the injectors
                        "To Find yourself, you must first lose yourself"

                        -1973 Volkswagen Bus Westy
                        -1986 Honda Magna 700cc
                        -1989 Lincoln Town car Signature Series
                        -2011 Subaru Outback

                        Comment

                          #13
                          I had new plugs put in just over a week ago, so I imagine they more or less look the exact same way they did when I bought them.

                          And I doubt it's my fuel injectors.

                          Comment

                            #14
                            If it's not the fuel filter or carbeurator, I suspect it's the fuel pump.

                            Worst case scenario, I replace:
                            - carbeurator
                            - fuel lines
                            - fuel pump
                            - fuel filter
                            - gas tank

                            Comment

                              #15
                              Check your vacuum lines. I had a similar problem with my '86 CV (of course mine is EFI and still running MAP) and it turned out the line was cracked going into the MAP sensor. It would run like crap and spew black smoke. But in any event, vacuum lines will make these cars run like crap.



                              Packman

                              Comment

                              Previous 1 2 3 template Next
                              Working...
                              X