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3 out of 4 cylinders firing

Discussion in 'Off Topic [BG]' started by graver555, Jul 5, 2014.


  1. graver555

    graver555

    Nov 6, 2012
    Monticello IN
    So I have had a bad injector in my truck for awhile that has been sticking open. I ran some b12 chemtool through the tank in hopes of cleaning it before replacing it. Instead it did the thing in and now I'm running on 3 cylinders. I don't have a cat so I'm not worried about the extra gas but I can't get it changed for a day or two.
    Should I pull the plug and try to disable that injector or just leave it since it is still running until I can fix it.

    It's a 98 s10 2.2 4cylinder. No idea on miles on the engine as all I know it's not original.
     
  2. nukes_da_bass

    nukes_da_bass Banned

    Feb 19, 2006
    west suburban boston
    I'd say run her gently. Look where tinkering got you.
    I've run taxis on missing sparkplug for a week on end.

    But I'm half sane.
     
  3. BassyBill

    BassyBill The smooth moderator... Gold Supporting Member

    Mar 12, 2005
    West Midlands UK
    As long as it runs on three as well as this does, you're fine.

     
    1958Bassman likes this.
  4. Mike N

    Mike N Missing the old TB Staff Member Supporting Member

    Jan 28, 2001
    Spencerport, New York
    Drive something else until you fix it.
     
  5. graver555

    graver555

    Nov 6, 2012
    Monticello IN
    Well I don't have a choice but to drive it, but I'm gonna drive it to class Monday and have someone pick me up from there, as I'm gonna have the auto department fix it. I just have to figure out how to get there without interstates.

    Looks like I'm just gonna run it. I'm gonna have me pressure test the cylinders to see if the engines worth keeping.
     
  6. I thought this was a thread about low T.:unsure:
     
  7. 1958Bassman

    1958Bassman

    Oct 20, 2007
    Take a whiff of your oil- if it smells like gas, change it. While you're at it, change the injector, too. DOn't drive your truck with oil that has been diluted with gas- the lubricity takes a complete dump and wears EVERYTHING.

    Unplug the harness from that injector and see if it changes anything.
     
  8. buzzbass

    buzzbass Shoo Shoo Retarded Flu !

    Apr 23, 2003
    NJ
    ^^^This^^^
     
  9. Pull all the injectors and send them to a shop for bench cleaning and test. I used Marren the one time I had it done.
     
  10. buzzbass

    buzzbass Shoo Shoo Retarded Flu !

    Apr 23, 2003
    NJ
    I'd say do a compression check/leakdown test. See if that hole is mechanically sound 1st. If it is, it should be easy from there
     
    1958Bassman and graver555 like this.
  11. Mike N

    Mike N Missing the old TB Staff Member Supporting Member

    Jan 28, 2001
    Spencerport, New York
    Agreed, but if he has an injector stuck open just dumping fuel in a cylinder it's going to wash the oil off the cylinder wall and screw with the compression/leakdown numbers.

    Id want to verify the injector itself is really the problem and it's not something else. To be honest I've rarely seen an injector failure in one of those trucks, we see more issues with the coil packs and plug wires than anything else.
     
  12. buzzbass

    buzzbass Shoo Shoo Retarded Flu !

    Apr 23, 2003
    NJ

    I'd have a tendency to agree, but the cleaner treatment has me a bit concerned. Someone in the R/T club did a seafoam treatment recently and blew a hole in the top of 2 pistons. We think he sucked it in so fast that he hydro locked the engine. But yes, plugs & injector are the easiest things to try 1st. Broken valve spring might be a good bet here too.

    OP, take the plug, wire & injector and move them to a different cylinder and see if the issue follows the suspected parts.
     
  13. 1958Bassman

    1958Bassman

    Oct 20, 2007
    But since compression and leakdown are done dry, that's kind of a moot point. I agree on the rest- the most important thing is, GET IT CHECKED OUT SOON.
     
  14. Mike N

    Mike N Missing the old TB Staff Member Supporting Member

    Jan 28, 2001
    Spencerport, New York
    You'd be surprised at how important having some oil on the cylinder wall is to proper ring seal. If you hose the cylinder down with a crapload of fuel it can skew your numbers.
     
  15. Mike N

    Mike N Missing the old TB Staff Member Supporting Member

    Jan 28, 2001
    Spencerport, New York
    I'm guessing the cleaner the op used was nothing more than an additive to the gas tank, your typical can of mechanic in a bottle.

    I'd agree that they sucked the seafoam in too quickly if they blew two slugs apart.
     
  16. graver555

    graver555

    Nov 6, 2012
    Monticello IN
    Well I had the plugs and wires changed a few months ago. Two weeks ago it wasn't running at all but we cleaned all the sensors real well and it fired up.
    I figured it was either the coil pack, compression, or fuel issue but I have a new fuel filter and strong fuel pressure at the rail. Along with the injector code it pulled I figured that was the culprit.

    Yes it was through the tank. However I seafoamed through the brake booster line and there was no immediate ill effects last week when I did it.
     
  17. Mike N

    Mike N Missing the old TB Staff Member Supporting Member

    Jan 28, 2001
    Spencerport, New York
    If you're getting an injector specific code you should measure the resistance of that injector and compare it to one of the others. Next I would use a noid light and verify the PCM is trying to fire the injector. If resistance is out of spec and/or you have no pulse at the injector then go after those issues first. If resistance and the noid check are good, listen to the injector with a stethoscope (or a long screwdriver) while the truck is running to see if you can tell whether the injector is actually firing or not. A functional injector will make a dinging sound as it cycles. Listen to a known good one for comparison.
     
  18. fhm555

    fhm555 So FOS my eyes are brown Supporting Member

    Feb 16, 2011
    Based on my experience with CDI and other HV ignition systems ^this^ would be the first thing I'd look at. Most of my experience is in motorcycles and marine engines, but solid state ignition systems are pretty much the same across the board, a control device, a voltage multiplier, a wire to carry the voltage to the plug, and the plug itself.

    Last time I was in the local AutoZone I saw they are now carrying spark testers, basically an adjustable gap that plugs into your plug wire to make sure you are getting enough voltage to your plug. Find the tool gap spec for your truck and it will take all of 10~15 minutes to insure your ignition system, at least down to the plug, is good.

    All you are going to do if you are dumping raw fuel into a jug that's not firing is ruining that jug pretty quick, and if you do it long enough the rest of your engine won't be long for this world either.

    Arranging a tow and a ride will be cheaper than replacing your engine.
     
  19. 1958Bassman

    1958Bassman

    Oct 20, 2007
    I know, but during the compression test for the other cylinders, the one without oil will be wetted by the oil on the rings, providing a better seal than if it had been running, then tested first without fuel. Besides, the compression test will require more than one revolution, anyway. My point was that fuel shouldn't be delivered to the cylinders during these tests. Easy enough with fuel injection- just pull the FP or Injector fuse.

    I would also recommend connecting a Noid light on all of the injector plugs.

    Edited to add-

    Upon re-reading the original post, I think it would be better to pull the injector plug, but I wouldn't drive it that way for very long and I wouldn't go very fast. This would create a badly unbalanced engine if this is done and major damage could result if it's treated like a farm animal.
     
    Last edited: Jul 6, 2014
  20. Mike N

    Mike N Missing the old TB Staff Member Supporting Member

    Jan 28, 2001
    Spencerport, New York
    If he has to replace the engine, may I suggest a 350? :D
     

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