Announcement

Collapse
No announcement yet.

"Gravity" start not possible on dead-battery FI Festy?

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • "Gravity" start not possible on dead-battery FI Festy?

    Today, after leaving my headlights on all day, I found the battery completely discharged. I pushed the car to the nearest (down)hill, got in, and figured I'd pop the clutch at 20mph to start. However, I got no response, despite having the ignition switch in the "on" position.

    I've done these "gravity" starts numerous times before, but they may have been in carbed models, and the battery was never completely dead.

    Question: Is there any reason a gravity start won't work with either a completely dead battery and/or a FI'd ('93) vehicle? Does it need just a little bit of electricity for the FI ECU???

    I ended up waving down a passing Good Samaritan with my jumper cables and was on my way in 5 minutes.
    Last edited by AlaskaFestivaGuy; 12-09-2011, 06:31 PM.
    88L black, dailydriver
    88LX silver a/c, dailydriver
    4 88/89 disassembled
    91L green
    91GL aqua pwrsteer
    92GL red a/c reardmg
    3 93L blue, 2 dailydriver, 1 frontdmg
    1952 Cessna170B floatplane

  • #2
    A completely dead battery won't start the car when popping the clutch.

    There needs to be just a little juice there to run the ECU, fuel injectors, coil, etc... it does not take much, but it can't be dead flat.
    1991 Mercury Capri XR2 "GTXR2" BPT Swapped AWD Conversion

    Rocketchips!
    High Flow B3/B6/BP VAF Adapters for sale!
    Bolt-on Weber Carb Adapters!

    Comment


    • #3
      An alternator needs some power to start making power. If the battery is completely dead, it will not work. It must have some electricity to excite the alternator to start producing power. Older vehicles with generators will not have this problem.
      1960 willys pickup
      1967 jeep cj5

      1988 festiva
      1989 festiva
      1990 festiva for parts
      1991 s-10

      "Democracy is two wolves and a lamb voting on what to have for lunch. Liberty is a well-armed lamb contesting the vote!" —Benjamin Franklin, 1759

      Comment


      • #4
        ^^^Didn't know that. Good to know.
        Buck.
        -1993 Ford Festiva GL, ~200k, B6, Aspire rear, Rio front, 5-speed. '87 Prelude alloys. Happy to be back on the route!!!
        -1999 Toyota Sienna XLE, 346,000
        -1996 Chevrolet K1500 Z71, 350 V8, 198k, hauler

        Comment


        • #5
          Takes power to make power .
          Edit. Slow phone .
          Last edited by shadetree; 12-09-2011, 06:55 PM.
          New build on the way .

          Comment


          • #6
            And if your battery is completely dead once you do get it going the battery will pull the maximum amperage possible. It will take out the main fusible link/cartridge fuse until the battery is partially charged. Best thing to regulate power to the charging circuit is let it idle for 10-15 mins. Otherwise, at highway speed the alternator can output enough current to smoke the fused main link. I did the same, left the lights on and got a jump. The normally 40 min return home took 3 hours and 4 cartridge fuses before the battery had enough charge to function.
            '93 Blue 5spd 230K(down for clutch and overall maintanence)
            '93 White B6 swap thanks to Skeeters Keeper
            '92 Aqua parts Car
            '93 Turquoise 5spd 137K
            '90 White LX Thanks to FB71

            "Your God of repentance will not save you.
            Your holy ghost will not save you.
            Your God plutonium will not save you.
            In fact...
            ...You will not be saved!"

            Prince of Darkness -1987

            Comment


            • #7
              Originally posted by worfdog View Post
              An alternator needs some power to start making power. If the battery is completely dead, it will not work. It must have some electricity to excite the alternator to start producing power. Older vehicles with generators will not have this problem.
              exactly! The residual magnetism will make enough power to start the engine
              but the dead engine needs to be turning around 3000 RPM to even make enough to excite the field, make power and start the engine. That's a pretty long steep hill.

              jump starting is generally safer and is less harsh to the drivetrain.
              Reflex paint by Langeman...Lifted...Tow Rig

              Comment


              • #8
                I have push started a Festiva without a battery.
                Just to see if it would, and it did. Died as soon as it stopped- but it did start.
                ~Austin
                Red 88 L (Ocho)

                Comment


                • #9
                  Originally posted by Oren09 View Post
                  I have push started a Festiva without a battery.
                  Just to see if it would, and it did. Died as soon as it stopped- but it did start.
                  Like, legit? Had acceleration?
                  Buck.
                  -1993 Ford Festiva GL, ~200k, B6, Aspire rear, Rio front, 5-speed. '87 Prelude alloys. Happy to be back on the route!!!
                  -1999 Toyota Sienna XLE, 346,000
                  -1996 Chevrolet K1500 Z71, 350 V8, 198k, hauler

                  Comment


                  • #10
                    Yeah. Didn't shift gears but it did take off and drive.
                    ~Austin
                    Red 88 L (Ocho)

                    Comment


                    • #11
                      All the field winding needs is @ 9V. If your stuck in Alaska with this scenario again. A 9V battery can get it going.But you would need some test leads with gator clips. Or some wires & Red Green tape. I used to put a switch in series with my field winding when I drag raced. Saves a little hp
                      Some people like to read fiction,I prefer to read repair manuals. Weird I know-
                      Henry Ford: "Failure is the opportunity to begin again more intelligently"
                      Fuseable Link Distribution Block repair link

                      Comment


                      • #12
                        Re PU241's caution about blowing fuses, I did let it idle for 5 minutes after being jumped, thinking I was putting enough charge back in to re-start if I stalled it at the stop sign at the bottom of the hill, then onto the freeway for 5 minutes to get home.

                        This morning, I ran 40 freeway miles of errands with 4 starts, all uneventfully.

                        Actually, the hill I was on last night was long/steep enough that I probably could have gotten it up to 3,000 rpm at 2nd-gear clutch engagement to force a start per Movin's suggestion. I might grab a dead (sitting in the weeds for 5+ years) battery and try that sometime.

                        Nitrofarm, I wasn't in AK. We only have about 50 miles of freeway-quality roads in the entire state (2.5 times the area of Texas), and none of it as "marked" Interstate. I've seen some government maps that show short stretches of "A-1" and "A-2" in Los Anchorage -- kind of like H-1, etc. in Hawaii, but the latter are posted as such.
                        Last edited by AlaskaFestivaGuy; 12-10-2011, 10:53 AM.
                        88L black, dailydriver
                        88LX silver a/c, dailydriver
                        4 88/89 disassembled
                        91L green
                        91GL aqua pwrsteer
                        92GL red a/c reardmg
                        3 93L blue, 2 dailydriver, 1 frontdmg
                        1952 Cessna170B floatplane

                        Comment


                        • #13
                          Have you dug into that b3 you grabbed a while ago from me ?
                          1992 white L, Bp, American racing 13's, stock trans.
                          1991 White L, BP/F5MR, protege header, full aspire swap with gr2's, seats, and sway bar, 15" konig's, short throw, escort console.
                          1991 blue L, 5 speed.
                          1988 red L-plus-all stock.

                          Comment


                          • #14
                            LOL, I envisioned you in Alaska with Kodiak Bears drooling over you while trying to Bump start.
                            Some people like to read fiction,I prefer to read repair manuals. Weird I know-
                            Henry Ford: "Failure is the opportunity to begin again more intelligently"
                            Fuseable Link Distribution Block repair link

                            Comment


                            • #15
                              It absolutely takes voltage to work the electric fuel pump and injectors think about it.
                              The days of mechanical fuel pumps and carbs are long gone.

                              I had some guys call me in a panic last summer "hey, do you know how to adjust points?"
                              A week ago, two guys were telling me "they actually met someone, knew how to "sweat a joint!"
                              Man do I feel old!
                              Last edited by iceracerdude; 12-11-2011, 12:52 PM.
                              97 Aspire w/K03 turbocharged b6 SOHC
                              CoolingMist Varicool II Meth injection
                              Phantom gripped and cryo'ed 5 speed

                              Comment

                              Working...
                              X