Question for some of the car experts

Discussion in 'Off Topic [BG]' started by LiquidMidnight, Oct 7, 2002.

  1. LiquidMidnight


    Dec 25, 2000
    Hey guys, wonder if you could help me with an automobile problem. A couple of weeks ago, my car began turning over very slowly. It will always start, but usually I need to step on the gas while turning the key. Also, the idle is definatley rough. Do you think it could be the fuel pump, or something having to do with the fuel injection. I've already checked the plugs, tryed dry gas and injector cleaner. I don't think it's a battery/alternator problem, because it seems to be keeping it's charge, plus I'm not getting any idiot lights for the battery.

    Thanks for your help gearheads.
  2. malthumb


    Mar 25, 2001
    The Motor City
    This won't answer your question but will hopefully give you some ideas where to look. The Internal Combustion Engine (almost all cars have them) works on the principle of several thousand small explosions per minute. It needs three things to achieve this:

    1) Air
    2) Fuel
    3) Fire

    Absense or restriction of any of these will cause the conditions you describe.

    If your air cleaner(s) is/are clogged, you're choking your engine.

    If your catalytic converter is clogged, you'll have a hard time starting.

    If your fuel filter is clogged or soiled or you have insufficient fuel line pressure, you'll have difficulty starting.

    If your fuel injectores or carburator need cleaning, you'll have difficulty starting.

    If your spark plugs are fouled or improperly gapped, you'll have trouble starting

    If your spark plug wires are fouled you'll have trouble starting.

    If your cars timing is off, you'll have trouble starting.

    You really should take it to a service station or dealer mechanic and have them put it on a "scope". It'll take @ 30 minutes and it will test for everything I've listed and then some.


  3. mchildree

    mchildree Supporting Member

    Sep 4, 2000
    Sounds like you have a couple of separate problems...

    1. Turning over slowly when starting tells me that you might have a battery that's weak (bad cell?) or not being charged by the electrical system. The fact that you aren't getting an idiot light doesn't mean much...those things are notorious for being non-functional. Don't depend on it. Take the battery to a parts store that has a tester...they'll usually test it for free and tell you if the battery may have a bad cell or something. If that checks out okay, have someone look at your starter.

    2. Running rough is a separate issue because once the car is started, the battery doesn't come into play. At that point, I'd suspect a clogged injector, or a timing problem (which could also be contributing to your hard starting problem). I'd check out the alternator too...a bad alternator could be causing all the problems you've described.
  4. Matthew Bryson

    Matthew Bryson Guest

    Jul 30, 2001
    has the weather been getting colder where you're at?
  5. LiquidMidnight


    Dec 25, 2000
    Thanks for all the input guys. I also forgot to mention that I did change the fuel filter.

    The weather is getting colder here Creepy, but I seriously don't think that's the problem.

    Thanks again.
  6. Mike N

    Mike N Missing the old TB

    Jan 28, 2001
    New York
    What kind of car? What size engine?
  7. A rough idle could be a number of things, and if you had a carbed car it would be easier to fix. Damn you and your fuel injection!! It could be a clogged fuel line, or like others have said, a bad spark plug. Replacing the plugs and points is a standard tune-up for most cars, and I hightly recommend it. Plus, I happen to think it's fun.:D

    Rock on
  8. Mike N

    Mike N Missing the old TB

    Jan 28, 2001
    New York
    Points?? GM and Ford stopped using them in 1975, and Mopar stopped in 1974. Hey Eric, what year is it where you live? ;)
  9. LiquidMidnight


    Dec 25, 2000
    Chevy Corsica with a 3.1, 6 cylinder (excellent engine I must say. I've had two cars with this type in them)
  10. Mike N

    Mike N Missing the old TB

    Jan 28, 2001
    New York
    Like has been mentioned before, get the battery and starter checked out for the slow turning over problem. As far as the rough idle, does it smooth out as you accelerate, or is it still rough? The 3.1 is common for coil packs dying, leaving your V6 running on 4 cylinders instead. This would run rough (and be down on power) all the time if a coil pack was dead. Ignition modules can go bad too, but thats usually a result of a bad coil pack. Wires ok? If theyre more than a few years old, might be time to change them. If your rough problem seems to only be at idle, look for any vacuum leaks, and try cleaning the throttle plate and bore. Very common on multi port engines for the throttle plate/bore to be dirty and cause a rough idle.

    I'll agree on the 3.1 (and its predecessor the 2.8) being a great engine, Ive seen lots of these with 150,000+ miles that still run great. However, in 1994-1995ish GM redesigned the heads/intake and called it the 3100, and Im not impressed with it. Runs ok but seems to swallow intake gaskets like theyre going out of style, and Im not seeing the mileage on these that I saw on the 3.1's.
    Also not impressed with the Dexcool that GM started using in '96, but thats another story.
  11. Beefbass

    Beefbass Guest

    Feb 4, 2001
    Yep, GM brought out the 3100 in 1994-the Buick Century's did away with the 3.3 for that. You're right, intake gaskets were always going bad.
    Does that car have an EGR valve? If so, that could be going bad. My 1989 Buick century had an EGR go bad, ran like crap till I replaced it. Also, could be getting carbon buildup in it.
    Check the alternator, see if it's charging the battery correctly. If it is, the battery may be going bad. Also, make sure the belt is tight.
    That Dexcool antifreeze is absolutely awful. First, it does not last to 150,000 miles(as claimed by GM) Dexcool is an acid compound. It just eats things up. On the 1996 and later Buick Lesabres, we were changing upper plenums regularly because of that. Also, if you mix regular antifreeze with that, the lifetime guarantee is gone, no matter what you do. You're better off just flushing that stuff out, and putting the green antifreeze in.
    Oh, do not put dexcool in an older car. Some of those have copper radiators. Dexcool is not good for those at all.
    Last, see if the car is setting any trouble codes in the computer. If it is, you'll at least know where to look.
    Good luck.
  12. Beefbass

    Beefbass Guest

    Feb 4, 2001
    Oh hey, I just thought of something. Your car may have a T shaped tube running along top of the engine-the Buick Century's with the 3100 did. It's for the emission system, and those were notoriuos for going bad. Car runs like crap when it does.
    Hope that helps.
  13. Dammit, cars stopped being good after 1972. Bring back the GT350!!!!:D

    Sorry, don't know why I even said that. Must be some sort of Fruedian thing.

    Rock on
  14. LiquidMidnight


    Dec 25, 2000
    Hey thanks for all the help guys. I'm thinking maybe the best thing to do is take my car to my mechanic.

    Mike, the idle is mainly rough while it's sitting, it seems to have enough power while driving.