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Car Failure Advice

  1. Jul 2, 2006 #1

    Clausius2

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    NOOOO is not my Firebird what is wrong, it is the 93 Ford Aspire of my roommate. It suddenly shut down when driving, deccelerating and finally swtching off. The ignition is working, but the engine does not start. It does not start and stalls, only it does not achieve to start. It does not seem a problem of the battery, the lights and electrics work well, but I have noticed a blue powder accumulation in one of the electrodes.

    At the beginning I thought it was because some spark plug failed, but I talked to my father (who turns out to be a good mechanician) by phone and he told me it should start even stalling with only three spark plugs. And it seems unlikely that the four spark plugs failed at the same time.

    Do you know what could be the problem? And please do not answer: take it to the mechanics, I already know that answer.

    Thanx.
     
  2. jcsd
  3. Jul 2, 2006 #2

    Astronuc

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    Perhaps the alternator or distributor, or a short circuit in between. I'd recommend changing out the cables from spark plugs to distributor and back to the alternator. To see if the spark plugs are firing one can remove one and turn the engine over to see if a blue spark is visible. The spark plug has to be ground to the block or other metal - but do not hold the spark plug to do this.
     
  4. Jul 2, 2006 #3

    Clausius2

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    Hi Astronuc, how's going? Glad to hear about you.

    Just a question: does modern car have a distributor? I mean, I thought now it was governed by electronics.

    Definitely it would be nice to check out if the spark plugs are firing or not.
     
    Last edited by a moderator: Jul 3, 2006
  5. Jul 2, 2006 #4
    Another thing i would check is that you have not only a good spark at the plug but that you have good compression in the cylinder head, blown head gasket or something ( if it aint electrical, which would be my first guess ).

    Get the compression tester out.
     
  6. Jul 2, 2006 #5

    wolram

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    Clausius2, try to start the car, take out a spark plug, is it wet or dry?
    if it is wet this indicated an ignition fault, if it is dry it indicates a fuel
    fault, a sudden stoppage with no prior warning (overheating) (knocks bangs)
    is usually one of the two.

    Do as Astro Said, take a plug out, Earth the outer body on the engine, and
    have some one crank the engine over while you watch the plug, you should have a blue spark, if you have no spark then start looking for bad/broken wire connections.
    If you have a spark and the plug was dry, you will have to start looking for fuel supply/blokage problem.
     
  7. Jul 3, 2006 #6

    FredGarvin

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    Fuel Pump! Pull the fuel line off of the carb/fuel rail and crank the engine. If no fuel comes out...If this is true, step two is to pray that his vehicle doesn't have an in tank fuel pump. I would like to personally kick the crap out of the braniacs that thought that one up.
     
  8. Jul 3, 2006 #7

    wolram

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    Fred, do think as i do, that a simple fuel, ignition system is no worse than an
    a computer controled monstrosity, i love diy but car manufactuers are putting that beyond our reach, hell the extra bits that go into car manufactuer probably cause more pollutants.
     
  9. Jul 3, 2006 #8

    Danger

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    Sounds more like a fuel problem to me as well. The intitial symptom doesn't seem to fit an electrical one. It probably would have stopped immediately rather than powering off gradually. That seems consistant with fuel starvation, although a seriously clogged air filter could possibly cause it.
    Try Fred's test. No fuel coming out might not necessarily mean a bad pump though. The outlet from the tank or the fuel filter might be plugged, or the tank might even be empty and the gauge is giving a false reading.
    If there is fuel coming out, check to make sure that it isn't contaminated with water or some other foreign substance.
     
    Last edited: Jul 3, 2006
  10. Jul 3, 2006 #9

    J77

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    Check the (I think they're called) ignition leads - the things that go from the plugs to wherever...

    Once on my car these were knackered which meant the thing was misfiring - when you started it, you could see sparks coming off them but not into the plugs or something...

    Anyway, I nothing nothing about cars - the homestart breakdown guy told me this was the problem and advised me to change them myself - they only cost around 15 pounds.

    Problem was fixed straight away.

    Could be your problem - at first I thought the battery was gone too.

    These things: http://www.autospares-group.co.uk/ignition-leads.php
     
  11. Jul 3, 2006 #10

    FredGarvin

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    I have to say that I am on the fence with this. As with anything, if one has the right tools, the job is easier. When I worked for Ford, it was very easy to diagnose engine problems with a voltmeter. If I could use a StarTac (hand held computer interface) it was even easier. Granted, there's a bit of learning to do and an understanding of how parameters effect one another is needed, but the fact remained that it was easy to pinpoint a lot of issues. That being said, I don't see the big 3 or anyone else providing a breadboard or breakout box for their EEC inputs to joe schmoe on the street. So it has made things tougher. It has also made mechanics dumber. Most I have seen simply parrot what the idiot box tells them and they usually end up chasing their tails looking for problems in stead of using the grey matter for a few minutes.

    Now that I don't work for Ford, I do hate that I don't have the same tools available to me and I wish cars were easier for the average guy. I am always on the look out for the diagnostic tools I used to have on EBay or something like that.

    As far as the polutants are concerned, in terms of emissions, I do not see how a carburated engine could come anywhere near the standards of a modern system with HEGOs and EVAP systems installed. I can't remember the statistics any longer, but the gains in tailpipe emissions were quite a bit less with electronic engine controls and evaporative emissions systems installed.
     
    Last edited: Jul 3, 2006
  12. Jul 3, 2006 #11

    FredGarvin

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    Good point Danger. My boss just had an issue with his Explorer. It ended up being the fuel filter. 99.9% of the people I know have never changed one and not had any problems. My boss was just lucky I guess.
     
  13. Jul 3, 2006 #12

    Astronuc

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    The pump and the fuel filter. Even if it is an internal fuel pump, one can perhaps undo the fuel line.

    I once had a Volvo that has a similar problem after I got filled it with contaminated gasoline - the delievery truck was filling the storage tanks and likely stirred up the 'sludge' which I managed to pump into my car. The fuel filter was blocked - and the mechanic at the repair shop told me I was lucky that the crud didn't get to the fuel injectors.

    As for the distributor, it could be solid state now, but it still disributes. I haven't kept track of which models have what type of distributor.
     
  14. Jul 3, 2006 #13
    first check for gas in the tank and look for missing wire or hoses connections
    then the clean battery terminals and inspect grounds straps/wires
    a lot of odd things relate to bad grounds

    if it sparks but will not run try shooting in starting fluid [ether] spray
    if it runs on that it is fuel related try pulling the gas cap and listening
    for the fuel pump buzz and then if the pump is running change the filter
    if no fuel pump sounds check fuses and or relays before changing the pump
    some cars you can jump around the fuel pump relays
    and some use the fuel pump as a failsafe to cut fuel if the oil pressure falls to low ect

    see if you can get the car to flash codes to report problems without a scan tool
    some will others need a tool/meter may depend on year and OBD type
    some GM cars will report codes with a paperclip jumper
    volvos need a push button only
     
  15. Jul 3, 2006 #14

    turbo

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    One thing - if the fuel filter is paper and you got a dose of water in with the fuel, the water will swell the fibers in the paper and starve the engine of fuel. I saw this happen a number of times when a local gas station had water contaminating its storage tanks. If the swelling is not bad, the vehicle will idle OK but will not accelerate. If the swelling is bad (lots of water) the engine will not idle and may not even start. Fuel filters are cheap, so this is a good thing to replace anyway.
     
  16. Jul 3, 2006 #15

    Danger

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    ...very carefully. Overdoing it is not at all good. In fact, I and some of my friends use WD-40 instead. It ignites with almost the same ease, but there's far less chance of an explosion.
     
  17. Jul 4, 2006 #16

    Clausius2

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    Thanks a lot to everybody for answering here.

    I liked a lot the idea of Wolram of checking if the spark plug is wet or dry after turning on the ignition. It would isolate at least the problem before getting it to the mechanics. Everybody knows that a mechanics can charge you a lot only for the time spent isolating the problem.

    It seems that my roommate has a great work ahead. My Firebird still runs neat though....
     
  18. Jul 6, 2006 #17
    There is a fuel rail ontop of the valve cover by the intake manifold. The fuel rail is connected to your injectors and is hard to miss. On the rail there will be a shrader valve (looks like a bicycle air valve) that you can press with your finger or a pen. Turn on the ignition and listen. You should hear the fuel pump HUMM for a few seconds. This is priming and pressurizing the fuel system. Now press the middle of the shrader valve and hopefully fuel squirts out. If it does not you have a bad fuel pump (also listen for that hum). If some fuel comes out, check the fuel filter to make sure it isnt half plugged. There is basically 2 things that could be wrong with the car...fuel or ignition. Compression won't be the problem.
     
  19. Jul 6, 2006 #18

    Clausius2

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    Thanks everyone.

    And the Oscar goes to.....

    Astronuc!!!. My roommate took it to the mechanics today and it was because of the distributor. Once replaced it is working again (after paying 260$).
     
  20. Jul 12, 2006 #19

    brewnog

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    So it's true, engineering professionals really do fix cars!
     
  21. Jul 13, 2006 #20

    BobG

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    What's so bad about an in tank fuel pump? Unless the pump dies all at once, with no warning, when you have a full tank of gas, of course (I actually had a pump that did that to me once, only a week after I'd installed it!)

    Just put up with poor acceleration until you get the tank nearly empty, clean the bottom of your car, duct tape some plastic to the bottom of the car above the tank to prevent any junk you couldn't clean off from deciding to become dislodged as soon as you remove the old fuel pump, leaving a nice round whole for debris to fall through, and it's no harder than replacing anything else on the car.

    Plus, when it comes time to start the car after the job is done, you can think about how those electrical wires you just connected are sitting unprotected in gasoline and wonder if this is what a suicide bomber feels like just before he turns the key.

    Replacing fuel pumps are loads of fun! :rofl:
     
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