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Code P1345

Discussion in 'Chevy Trucks' started by MarkEagleUSA, May 3, 2011.

  1. MarkEagleUSA

    MarkEagleUSA Senior Member
    Messages: 321

    My truck died last week with all the symptoms of a bad fuel pump. Testing the pressure (which was low: 58-60 psi) I decided to try changing the filter before dropping the tank and doing the pump. Pressure came back to within spec (64 psi). At the same time the truck threw the P1345 code. Turns out the distributor hold down was loose and apparently it moved.

    I got a hold of a code scanner that would read the CAM ****** value and found it to be 22 (spec is +/-2). Turning the distributor clockwise as far as it would go I was able to get the CAM ****** down to 2 and the P1345 hasn't some back.

    My question is this: since I can't turn the distributor any farther would that be an indication that the gear is worn (seems to be a common problem associated with P1345) and/or the distributor should be replaced?
     
  2. BlizzardBeater

    BlizzardBeater Senior Member
    from Maine
    Messages: 420

    If it came loose, its possible it jumped a tooth which would throw it off. Take the distributor cap off, line the crank up so the motor is at TDC (top dead center), and check to see where the rotor is pointing. It should be pointing to the number one fire position if its a vortec. If its an older motor, it should point straight forward.
     
  3. MarkEagleUSA

    MarkEagleUSA Senior Member
    Messages: 321

    I pulled the disty and found that the gear was severely worn. So much so, in fact, that I could use it as a razor if I wanted to!

    Installed a new disty, set the CAM ****** to 0 (@1500 RPM) and finally got rid of the P1345 code. However, there is still a "knock" right at the point when the throttle is applied. The knock is rather loud but only for a split second or so. No other codes are being thrown and everything else seems to be fine. I'm stumped and don't know where to look or what to do next. :confused:
     
  4. BlizzardBeater

    BlizzardBeater Senior Member
    from Maine
    Messages: 420

    You can try advancing the timing a degree or two.
     
  5. MarkEagleUSA

    MarkEagleUSA Senior Member
    Messages: 321

    Tried that... no noticeable change.

    It now sounds to me like it's possibly fuel related. At idle there are occasions where the engine seems to skip until about 1000 rpm, then everything seems to smooth out. When it skips there is a slight knock as well. Idle rpm is around 650 in park and about 550 in drive with my foot on the brake (and the skip is more pronounced). Is that normal or does it seem on the low side? Fuel pressure is still around 64 psi key on engine off and 58-60 psi running so I don't think it's the fuel pump.
     
  6. BlizzardBeater

    BlizzardBeater Senior Member
    from Maine
    Messages: 420

    Thats plenty of fuel. If its running fine otherwise without throwing any more codes, a lot of times rough idles are tune up issues. Spark plugs, wires, cap, and rotor will smooth things out many times.
     
  7. MarkEagleUSA

    MarkEagleUSA Senior Member
    Messages: 321

    Everything is new from the fuel filter forward: disty, CPS, cap, rotor, wires, plugs, PCV & air filters. And it's more than a rough idle... there's a definite skip/misfire like it's not getting a steady flow of full.

    Been working on it a little this morning. I was checking underneath to see just what's involved in droppong the tank and I think I may have discovered part of the problem. It looks like the fuel line (feed) must have rotted between the tank and the filter and someone put in about a 4" long repair section with what looks like compression fittings. The rubber section that goes up to the tank is bent pretty sharp and looks like it collapsed enough to restrict the flow (volume). Looks like I'll be dropping the tank and replacing everything between it and the fuel filter.

    Ugh! Not how I wanted to spend my weekend (or my money). :mad:
     
  8. BlizzardBeater

    BlizzardBeater Senior Member
    from Maine
    Messages: 420

    Definately should replace it, however, if your not getting enough fuel, running would be worse than idle. If your not getting enough fuel, idle calls for the least. The more that you press the gas pedal, the more fuel it requires. So if its running fine above idle, chances are your fuel is fine. Although there are exceptions to the rule. Replace it anyway if its not right.
     
  9. MarkEagleUSA

    MarkEagleUSA Senior Member
    Messages: 321

    After loosening the compression fittings and removing the line from the plastic clips on the frame rail I was able to rotate it slightly and get rid of the kink. Testing the fuel pressure after didn't show any increase in psi.

    My problem is only at idle. In fact I drove about 40 miles today really jumping on it and acceleration and highway speed is fine though it feels like there's a slight skip under load.

    There are no codes being thrown and I still have the rather loud knock at idle when the throttle is first applied. I am completely stumped on what the problem is. Could this be indicative of an injector going bad?
     
  10. Sydenstricker Landscaping

    Sydenstricker Landscaping PlowSite Veteran
    Messages: 3,882

    I would take it and have it put on a good scanner that can check things while it is running. They can then check each injector, etc while it is running. I know those spider injectors on the vortecs aren't known for longevity as well as the intake manifold gaskets being poop
     
  11. MarkEagleUSA

    MarkEagleUSA Senior Member
    Messages: 321

    About at my wits end here... the only place I can find to test the injectors is the dealer and I simply cannot justify paying their diagnostic fee for a 5 minute job.

    Since the injectors are a known issue on the Vortec I think I will just bite the bullet and put in the new style injector spider. If that doesn't solve the problem there will be a slightly (ab)used 97 2500 for sale cheap here in Connecticut! :eek:
     
  12. MarkEagleUSA

    MarkEagleUSA Senior Member
    Messages: 321

    Problem solved... and I'm almost too embarrassed to say what it was. :eek:

    It turns out that one of the flywheel-to-T/C bolts loosened up and backed out just enough to make contact with the casing. At low idle there apparently was enough wobble to cause my mystery "knock". At higher RPM's the knock went away (or at least couldn't be heard). What had me puzzled was the fact the I could actually feel the knock at the throttle body when manually applying throttle.

    How did I discover this? This afternoon I started the truck so I could pull it over to the garage and begin replacing the fuel injector spider. When the engine fired, the bolt head sheared off and made a heck of a rattle for a couple of seconds.

    So I crawled under and removed the inspection cover bolts. Not wanting to mess with the heavily rusted exhaust bolts, I couldn't totally remove the cover but was able to move it out of the way enough to see what was going on. Dug out a bolt from the spare parts collection to replace the broken one and made sure all the others were tight (only one other was loose). I had to turn the flywheel about 3 teeth at a time with a screwdriver so it took a while but I got them all snugged up and now the knock is gone! What a relief especially since I didn't have to shell out over $300 to replace the spider (at least not yet).

    There's still a very slight miss detectable only at idle. It doesn't happen all the time, just mainly when the engine is cold. For now I'm not going to worry about it. I'll use a couple of bottles of Sea Foam or injector cleaner in the fuel to see if it helps.

    I guess I just got lucky, and like the old saying goes, I'd rather be lucky than good any day! :nod:
     
  13. BlizzardBeater

    BlizzardBeater Senior Member
    from Maine
    Messages: 420

    Glad to hear you found it before it got real expensive!
     
  14. MarkEagleUSA

    MarkEagleUSA Senior Member
    Messages: 321

    Fortunately all the money I spent was legitimate. New distributor (the original problem), complete tune-up and filters were all necessary anyway.