Engine wants to stall at highway speeds

Discussion in 'Shop Talk' started by WanderingOak, Sep 29, 2004.

  1. WanderingOak

    WanderingOak Well-Known Member

    Messages:
    1,287
    Joined:
    Jul 12, 2004
    Location:
    New York
    I have an 88 S-10 with a 4.3 V6, and she's been acting up a bit on me lately. I was driving home from work on I66, through the remains of Hurricane Jeanne, when all the sudden, my truck started slowing down. Because of the noise from the storm, I couldn't tell if my engine was running or not, although my gauges were all good, and I didn't have any idiot lights on. I gave it more gas, and nothing happened for 2-3 seconds, until suddently the truck downshifted and surged forward. I kept to the slow lane for a while, paying very close attention to how my truck was driving, when I started to notice my engine start to 'hitch' every now and then- especially on hills. However, I still didn't have any warning lights. When I pulled into a gas station to tank up, the engine died on her own as soon as I pulled up to the pump. After gassing up, she started right back up. I made it home on back roads without a problem, and made in to work this morning as well.

    The only thing I can think of is that I may have water in my gas or a bad sending unit- I was just under half a tank at the gas station. If I was having an electrical problem, my dash would have lit up like a Xmas tree, but it didn't. My fuel pump is less than a year old, and I replaced my ignition wires last spring. Anybody have any other ideas?
     
  2. moopups

    moopups In Remembrance

    Messages:
    7,102
    Joined:
    May 12, 2002
    Location:
    In beautiful downtown Sticks, near Belleview, Fl.
    1 Clogged fuel filter
    2 Unvented fueltank cap
    3 Humidity clogging air filter
    4 Wet electrical connections
    5 Failing fuel pump
    6 Colapased fuel line
     

  3. WanderingOak

    WanderingOak Well-Known Member

    Messages:
    1,287
    Joined:
    Jul 12, 2004
    Location:
    New York
    1 Clogged fuel filter
    Changed less than 20K miles ago.

    2 Unvented fueltank cap
    Need to look further into that.

    3 Humidity clogging air filter
    Need to look at that as well. Filter is K&N- oil permiated cotton, not paper.

    4 Wet electrical connections
    Possibly, although worked fine after gas station. Back roads almost flooded, yet no problems with engine.

    5 Failing fuel pump
    Almost new. Still under warranty.

    6 Colapased fuel line.
    Another possiblity, although would it 'un-colapse'?
     
  4. rambler

    rambler Well-Known Member Supporter

    Messages:
    8,275
    Joined:
    Jan 20, 2004
    Location:
    MN
    Just remember, you have not eliminated anything with your items.

    #1 - just takes one bad tank of fuel to plug it right up again.

    #4 - When you stopped, engine heat allowed it to dry, and it didn't get splashed the same way on the back roads.

    #5 - Lots of stuff I replace, the replacement is defective. Wish things worked when new...

    These intermitent problems are the worst to solve - never know if you really found it or not.

    --->Paul
     
  5. WanderingOak

    WanderingOak Well-Known Member

    Messages:
    1,287
    Joined:
    Jul 12, 2004
    Location:
    New York
    Just before the engine died at the gas station, I had to drive under Niagra Falls, The roof over the gas island was leaking along one side. You're probably right about the ignition wires geting soaked, then drying out from the engine heat. Once everything dries out (no garage), I'll need to take a closer look under the hood to see if everything is tight.
     
  6. insanity

    insanity Well-Known Member

    Messages:
    890
    Joined:
    Aug 22, 2004
    Location:
    Clarksville TN.
    Have you changed the O-2 sensor lately? The one on my truck is giving me problems at highway speed under no load it tends to act as if it is loading up on fuel,(like you described),also mine misses at idea at times.Runs like a dream if you raw hide it.

    At least i think this is whats wrong with mine,i will not no for sure until next week when i can afford to change it. Every thing else i can think of checks out good.Well other than the catalytic converter, but it isn't that old.

    Also you might want to check for vacuum leaks around the throttle body(just spray around it with starter fluid,and listen for changes in idle).My wifes van has the same engine with 115k miles on it.Low idle and misses at idle speed.It is sucking air around the throttle linkage on the throttle body.Junk yard priced it to me for 15 dollars new over 150 :eek: .I think ill be try the junk yard.Its not that hard to change so even if i have to go threw a couple it would be worth it.

    Also on this engine if a plug wire touches anything metal it will arc out.Might look them over real good.
     
  7. DrippingSprings

    DrippingSprings In Remembrance

    Messages:
    1,947
    Joined:
    Sep 22, 2004
    Location:
    Alabama
    bad ignition coil
    bad throttle position sensor
    bad gas

    they first two can be checked rather easily with a digital voltmeter
     
  8. herefordman

    herefordman Well-Known Member

    Messages:
    194
    Joined:
    Aug 24, 2004
    Location:
    washington/british columbia
    Stick with the bad fuel filter idea, they have a little plate inside that is notorious for falling off, blocks the line then stalls, the plate drops back, you get running again then the plate pops back up and blocks the line again.
    Also the GM/Carter electric fuel pumps are known for failing reguarly don't rule it out just because its new.
     
  9. greg273

    greg273 Well-Known Member

    Messages:
    9,621
    Joined:
    Aug 4, 2003
    Location:
    southern illinois
    Check the ignition/spark plug wiring harness for any worn-through spots, that would cause an intermittent loss of power. I had a 98 s-10 that had a factory recall due to a wire that was badly placed and rubbed against the engine, shorting it out often.
    good luck!
     
  10. WanderingOak

    WanderingOak Well-Known Member

    Messages:
    1,287
    Joined:
    Jul 12, 2004
    Location:
    New York
    Thanks for all the suggestions. I think the problem was a mostly clogged air filter. It probably got a little bit damp during the storm, which just made the airflow even more restricted. I cleaned out the filter and re-oiled it and now she's running like a top.