What's wrong with my s10?

Discussion in 'Shop Talk' started by AnnaS, Aug 2, 2005.

  1. AnnaS

    AnnaS Well-Known Member

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    This is my 91 S10, 4 cyl. engine 110k manual, no options (not even a radio).

    A couple of weeks ago, I was driving along and it started chugging, lost power and finally died. It started again after about an hour. I replaced the fuel filter (which the previous owner had never done) and it doesn't chug now but it does drop dead after about 2 miles. The SES and battery lights come on a second before the engine dies. It idles and runs fine up until it dies.

    My neighbors are tractor restorers and they checked the spark plugs & wires, battery and connectors, listened to the fuel pump and pulled codes- just gave 12s no other codes.

    Any ideas?
     
  2. Randy Rooster

    Randy Rooster Well-Known Member Supporter

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    Put on a new distributor cap and rotor.
     

  3. Cabin Fever

    Cabin Fever Life NRA Member since 1976 Supporter

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    In this heat, coupled with modern gasoline with its high alcohol content, vapor lock is often a problem causing symptoms like you've described. When this happens, pour some cold water over the fuel line in the engine compartment. If the engine then starts and runs fine, it was probably vapor lock. The only way to fix it is to re-route the fuel line away from heat sources (such as the exhaust manifold or pipe), or the strategic placement of heat shields between the fuel line and heat source.
     
  4. Cosmic

    Cosmic Well-Known Member

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    Yup, could be vapor lock but it should have showed up before, seeing as how you got 100K+, if your installation would be prone to it.

    Might also be a worn fuel pump. Does it die on level ground or going down hills, usually shows up the worse going up hills??? Or does it make any difference???

    Would also check the timing and give the carb a good spray cleaning. Cleaning can do wonders for a truck that runs poorly and you swear it is ready for the junkyard. Also do a general tune up check off, plugs, air filter, etc. Be sure to spray clean the PVC line / valve too.

    Might be as simple as crap gasoline. Get a bad tank with any water and it can drive you nuts. Try putting in a can of dry gas.
     
  5. gardentalk

    gardentalk Well-Known Member

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    I'm not a mechanic (obvious from my post), but this might help. We had a '98 Kia (good thing the wife wrecked it, it was a horrible vehicle) and for awhile it would do something similar to what your S10 is doing. Instead of the Kia discontinuing running, it would require about an hour's wait before it would start up again. Someone told me to get under the Kia and hit the starter with a wrench. I did, and no more problems after that.....at least not until Mr. Kia said hello to Mr. Telephone Post. :p
     
  6. agmantoo

    agmantoo agmantoo Supporter

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    Anna, after the filter change, when the engine dies will it restart immediately? Are you accelerating or under load, such as going uphill, when the engine dies?
     
  7. Cosmic

    Cosmic Well-Known Member

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    Part of the reason you really want to spray clean that carb good. Run the engine at high revs and pump it in good. Should get a lot of whitish type mist / smoke out the exhaust. Blows a lot of the cat crap out too. Usually I do the entire big can. On fuel injection, put a can in the gas tank and then spray some in the air side after the air filter. Usually can find a connector to allow you to to spray into the intake air. Can also find hoses to the intake manifold and spray it in there.
     
  8. Ross

    Ross Moderator Staff Member Supporter

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    It needs a tune up including a PCV valve, which is probably plugged. Although if that doesn't fix it you need to check the fuel pump/relay, but I really think its tune up related, PCV prob likely.
     
  9. skruzich

    skruzich Well-Known Member

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    Well if it has no codes, i doubt its going to be much in the line of tune up. You would get codes from the o2 sensor if it is tune up related. I would think it is the fuel pump or relay. I have three s10's and that is what i have to replace every time it does what you said happened.

     
  10. cfabe

    cfabe Well-Known Member

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    The engine in this vehicle is throttle body fuel injection and has a normal distributor. It's not vapor lock, not possible on that vehicle. The suggestions of a fuel related problem, pump, relay, filter, or of a flakey ignition module are good. If you have access to the equipment, you can test the fuel pressure when it's not starting, and if there's no or little pressure that's your problem. Absent a gauge, you can take off the air cleaner and look in the throttle body and you can visually see the fuel spraying out of the injector. Check when it's running so you know what to look for.

    FYI the ignition module for this car is around $40, and many parts stores can test yours for you, though if it's intermittent, it may still test good. If you haven't kept up on maintainence, now would be a good time to replace the spark plugs, ignition wires, and cap and rotor, airfilter, etc.
     
  11. georger

    georger Well-Known Member

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    Here, I'm going based on my memory from an 86 2.0 L 4 banger with central injection. It's likely the same as the 91.

    No harm in just changing the module. It's cheap enough.

    But make sure you get a GM part. I've found that some patterned modules (non-GM) sell at a lower price - and fail earlier too!

    If you change the module yourself, make sure to clean off the old dielectric grease from the distributor. Clean it all off very well!

    Don't touch the metal surfaces. Oil from your skin will intefere with the grease's function - to accomodate heat transfer.

    Clean the module's metal surface as well as the metal surface where the module will live (usually inside the distributor).

    Methyl hydrate works great at this. You want the surfaces to be as clean as possible. If there is rust on the plate where the module mounts, sand it off first.

    Use a clean object - clean popsicle stick works well - and smear a THIN and even coating of new dielectric grease (supplied with the module) on the metal side of the new module. Don't use your fingers or a dirty screwdriver.

    When installing it, tighten the mounting screws in gradual steps, first one side and then the other.

    Don't over-tighten or you risk cracking the module and warping the metal backing. It's only aluminum (usually). Usual tightness runs around 100-120 inch-pounds if I remember correctly.

    While you've got the distributor open, might as well change any other parts that might need changing.

    The ignition module not only fires the coil, it's responsible for picking up and sending the pulse to the computer that times the fuel injector(s).

    So an intermittent in this module will bugger both fuel and spark.

    For such a relatively low cost, just change it - you can't go wrong that way!
     
  12. gccrook

    gccrook Well-Known Member

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    Wow! THat sounds just like my 1989 Chevy Cavalier 4 banger. My mechanic said it was the module and the coil. He wanted too much to fix it, so I am going to do it myself, but I decided to change the plugs and wires first. Will let you know how that goes.
     
  13. georger

    georger Well-Known Member

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    Usually...the coil is ok. Check for signs of arcing, let it run in the darkness and look for sparks leaking out from around it.

    If you don't see or hear any spark noises, and if you can pull at least an inch and a half of spark off the engine block, chances are the coil is fine.

    Most mechanics change the coil simply as a matter of precaution, because a defective coil can damage a module and they don't get paid for callbacks.