Results 1 to 20 of 20

Thread: Start Engine

  1. #1
    Senior Member
    Join Date
    Jul 2006
    Location
    Wahiawa
    Posts
    587

    Start Engine

    Starting car first time in the day whether 7:00 am or 2:00 pm, it will not start unless I depress the gas pedal twice. BUT, when I drive it at least a mile, park it, and try to start it after 3 hours or more, it will start whether I depress the pedal or NOT. Go figure! Why is that ? Any clue?

  2. #2
    Senior Member
    Join Date
    Nov 2008
    Posts
    335
    If it has a carburetor, that's perfectly normal.

    If it's a fuelie, it's broken.

  3. #3
    Senior Member
    Join Date
    Jul 2006
    Location
    Wahiawa
    Posts
    587
    Yes, it has a carburetor. What in heck is fuelle, and broken? Can you explain more clearly?

  4. #4
    Administrator Ken's Avatar
    Join Date
    Jan 2008
    Location
    Lincolnshire, United Kingdom.
    Posts
    3,415
    'Fuelie' Fuel Injected engine. 'Broken' with a FI engine there should be no need to touch the accelerator to start the engine.

    Pumping the gas pedal on a cold engine will pump a couple of squirts of fuel (via the accelerator pump) into the engine to aid cold starting. When the engine is warm this enrichment of the mixture is not necessary.

    Ken. (Mazda3 TS2 2.0L 'Fuelie)
    Die dulci fruimini!
    Ken.
    Wolds Bikers, Lincolnshire, England.

  5. #5
    Senior Member
    Join Date
    May 2013
    Location
    Southside, Virginia, way out in the sticks.
    Posts
    104
    Way to go, Ken. That was a very concisely stated explanation. The gasohol mixture available here has ruined yet another carburetor for me. I'm about to order one for my '68 F250.

  6. #6
    Senior Member
    Join Date
    Nov 2008
    Posts
    335
    Before you go to the expense of replacing a carburetor, assuming the vehicle still runs, put a quart of Marvel Mystery Oil in the fuel tank and go for a ride. If the symptoms don't go away in fifty miles or less, then you probably do need a carburetor.

    Thanks, Ken, for explaining my brief response.

    Oddly enough, the converse is also true.
    I'm embarrassed to admit this.
    One fine day my 03 Explorer wouldn't start.
    I removed the fuel tank and separated the fuel pump, verified that the pump worked and there was nothing in the tank but a little fuel.
    After reassembly, it still wouldn't start.
    By accident, I discovered that if I depressed the gas pedal just a little, it would start, and run fine, but it would immediately stall at idle.
    It turned out that the idle air circuit in the throttle body was clogged.
    A little squirt of carb cleaner in the right place fixed it right up.
    The MMO in the tank would have fixed it too, without disassembling anything.

  7. #7
    Senior Member
    Join Date
    Jul 2006
    Location
    Wahiawa
    Posts
    587
    I never thought of it that way.

    Thanks

  8. #8
    Senior Member
    Join Date
    May 2013
    Location
    Southside, Virginia, way out in the sticks.
    Posts
    104
    Quote Originally Posted by MikeHalloran View Post
    Before you go to the expense of replacing a carburetor, assuming the vehicle still runs, put a quart of Marvel Mystery Oil in the fuel tank and go for a ride. If the symptoms don't go away in fifty miles or less, then you probably do need a carburetor.
    Good call, Mike. I tried that first when it started showing symptoms of a bad accelerator pump. Unfortunately, it's time for a rebuilt, which is probably for the best because of the carb I had to buy last time, about '02. The only one I could find locally had an electric choke, which worked intermittently. I left the choke cable in place and will get the one with the cable actuated choke from Rock Auto. $168 + shipping. Not too pricey, if it's a US rebuild.

  9. #9
    Senior Member
    Join Date
    Jul 2006
    Location
    Wahiawa
    Posts
    587
    >>Pumping the gas pedal on a cold engine will pump a couple of squirts of fuel (via the accelerator pump) into the engine to aid cold starting. When the engine is warm this enrichment of the mixture is not necessary.<<

    All right Ken, But, sometimes, even when the engine is warm, trying to start it without pressingdown the gas pedal, it will not start, unless I press it down about half-way. Please explain. Maybe the carb need a tune up or something.

  10. #10
    Administrator Ken's Avatar
    Join Date
    Jan 2008
    Location
    Lincolnshire, United Kingdom.
    Posts
    3,415
    All right Ken, But, sometimes, even when the engine is warm, trying to start it without pressing down the gas pedal, it will not start, unless I press it down about half-way. Please explain. Maybe the carb need a tune up or something.
    A carb tune up, if it hasn't been done for a fair while could well be needed.

    My approach would be, make sure the carbs are clean, properly set up and balanced, check that the ignition timing is correct (static and dynamic) and that cylinder cranking pressures are within tolerance and balanced to within five to ten psi. If all these factors are dealt with then the need to depress, or not depress, the accelerator will be a characteristic of your engine and very likely dependent upon temperature, fuel being used and the inlet tract gas velocity at cranking speed.

    Having said that, if your car starts readily - using throttle as necessary - and runs well with reasonable gas economy and performance then my guess is that it is just a characteristic of your engine.

    Ken.
    Die dulci fruimini!
    Ken.
    Wolds Bikers, Lincolnshire, England.

  11. #11
    Senior Member grouch's Avatar
    Join Date
    Jan 2008
    Posts
    2,133
    Quote Originally Posted by ChevyMan View Post
    >>Pumping the gas pedal on a cold engine will pump a couple of squirts of fuel (via the accelerator pump) into the engine to aid cold starting. When the engine is warm this enrichment of the mixture is not necessary.<<

    All right Ken, But, sometimes, even when the engine is warm, trying to start it without pressingdown the gas pedal, it will not start, unless I press it down about half-way. Please explain. Maybe the carb need a tune up or something.
    Being in Hawaii it's fairly warm where you're at. (It's snowing and blowing cold air here.) The heat of your engine will evaporate the little bit of fuel in the intake. A slight pump will squirt some more. Once it's running, the venturi ports will draw fuel in to keep it running. I wouldn't worry about it. Now, if you have to hold the brake with one foot while you give partial throttle with the right, then you do need a new carburetor.
    Honk if you love Jesus.

    Text if you want to meet him.

  12. #12
    Senior Member
    Join Date
    Nov 2008
    Posts
    335
    And if you squirt it too many times, or the fuel hasn't evaporated from the manifold, a hot engine may refuse to start because it's 'flooded', i.e. the carb is supplying too much gas. The problem was solved long ago with a 'choke unloader' mechanism, that opens the choke a little when you depress the accelerator more than halfway down while cranking. (in some cases you need to press pretty hard/far.) IOW, your carb is working pretty much as intended.

    If you can find the _real_ manual for your carb, it will contain a procedure for checking and adjusting the choke unloader, and about 15 dense pages of other fiddly adjustments, too. Most of the adjustments require no special tools other than drill bits used as gages to set various openings, like how far the unloader opens the choke.

    If you can get the real book for your exact carburetor, you will probably find that most rebuilds don't even use the correct core, much less have all the adjustments set correctly. Getting a carb set up right can make a huge difference in how an engine runs, but it's labor-intensive and a little bit skill-intensive, so nobody processing hundreds of carbs a day is inclined, or able, to bother.

    If you are ever lucky enough to own a 140HP Corvair, with four single barrel carburetors of two different kinds and a wobbly interconnect mechanism that has to be grasped just right to get them synchronized, you will learn a great deal about carburetors...

  13. #13
    Senior Member
    Join Date
    May 2013
    Location
    Southside, Virginia, way out in the sticks.
    Posts
    104
    "
    If you are ever lucky enough to own a 140HP Corvair, with four single barrel carburetors of two different kinds and a wobbly interconnect mechanism that has to be grasped just right to get them synchronized, you will learn a great deal about carburetors..."

    Now that would be a learning curve indeed. I never knew that Corvairs were so complicated, but then I never owned one. My uncle had a pretty basic model that he let me drive as a learner, and I loved it. I guess the more high performance models were really something to drive.

  14. #14
    Senior Member
    Join Date
    Jul 2006
    Location
    Wahiawa
    Posts
    587
    Quote Originally Posted by grouch View Post
    Being in Hawaii it's fairly warm where you're at. (It's snowing and blowing cold air here.) The heat of your engine will evaporate the little bit of fuel in the intake. A slight pump will squirt some more. Once it's running, the venturi ports will draw fuel in to keep it running. I wouldn't worry about it. Now, if you have to hold the brake with one foot while you give partial throttle with the right, then you do need a new carburetor.
    Now, why should I hold the brake while starting it that way? The car is in "Park", after all.

  15. #15
    Senior Member
    Join Date
    Jul 2006
    Location
    Wahiawa
    Posts
    587
    >> IOW, your carb is working pretty much as intended<<. I'm relieved to hear you say that. When the engine is still warm but will not start without priming the carb, I have to depress the gas pedal all, or almost, all the way down, while turning the key. BTW, it's a 4 barrel QuadraJet carb.

  16. #16
    Senior Member grouch's Avatar
    Join Date
    Jan 2008
    Posts
    2,133
    Quote Originally Posted by ChevyMan View Post
    Now, why should I hold the brake while starting it that way? The car is in "Park", after all.
    Not so much starting it but when you're driving it. If your idle ports are blocked, the gaskets are dried out or your casting is old and porous, the car will stall when you come to a stop. Then you have to give it a little gas to keep it running but you also have to hold the brake to keep from taking off.
    Honk if you love Jesus.

    Text if you want to meet him.

  17. #17
    Senior Member
    Join Date
    Nov 2008
    Posts
    335
    Maybe we need to review a bit, because the protocol for starting a carbureted engine is different hot/cold.
    There should be a procedure in the car's owners manual.
    If you can't find it, you may be able to buy it from helminc.com .

    Hot: Do not 'pump' the accelerator; just hold it partway open and turn the key. If it doesn't start right away, then press the pedal to the floor and turn the key.
    Cold: Pump the accelerator a couple of time, hold the pedal part way down and turn the key.

    The optimum number of times to pump the pedal, and how far 'partway' really is, depends on the particular engine. It will tell you its preferences by starting, or not starting. The procedure may have to be adjusted a bit as things age, but there should be little variation from day to day. Some engines with complicated carb linkages will cold start better if you press the pedal all the way to the floor before attempting a start, then press the pedal part way, then turn the key.

    I think some of the last/ most recent carburetors had Idle Air Control valves, little poppets driven by a stepping motor to provide idle mixture (instead of a separate passive idle mixing circuit within the carb body). If an IAC is present and working, you don't press the gas pedal at all to start; just turn the key and let the computer figure out how much to open the IAC.

  18. #18
    Senior Member
    Join Date
    Jul 2006
    Location
    Wahiawa
    Posts
    587
    >> Then you have to give it a little gas to keep it running but you also have to hold the brake to keep from taking off.<< Okay, that clears up what you meant by holding the brakes.

  19. #19
    Senior Member
    Join Date
    Jul 2006
    Location
    Wahiawa
    Posts
    587
    Quote Originally Posted by grouch View Post
    Not so much starting it but when you're driving it. If your idle ports are blocked, the gaskets are dried out or your casting is old and porous, the car will stall when you come to a stop. Then you have to give it a little gas to keep it running but you also have to hold the brake to keep from taking off.
    So far, the car hasn't hasn't stalled ' when it comes to a stop'. Not yet, anyway. The only time I have problem starting it is when I park it after driving it for a while, I sometimes have to try start it with the pedal ALL the way down and turn the key (similar to a *flooded" carb procedure). Other than that, no problem at all. The car only have 57000 plus miles on the odometer.

  20. #20
    Chev - I guess I'm old, or at least most of my cars have been. ('65 seems to have been my favorite year.)
    The old double-pump on the gas was SOP for cold starting one of them.

    MikeH - yoiks! Back in '83 I was buying a used car - it came down to a bright yellow Corvair, or a Citroen DS19 ID; I got the Citroen. As troublesome as that car could be at times, (hydraulics), I think maybe I made the right choice.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •