99 5.7 distributor issues

Discussion in 'GM Powertrain' started by vicar75855, Sep 15, 2010.

  1. vicar75855

    vicar75855 Rockstar 100 Posts

    Hey ya'll...

    I Have a 1999 K1500 Suburban with the 5.7 Vortec

    Last month while driving about an hour from home the Sub started acting like it had no power, the CES started flashing anytime you got over 45mph. Limped home at 30 we had 0300 174, and a host of other codes.

    I just cleaned the intake upper and lower, and installed the good felpro set.
    After the install we found slightly low comp on two cyl so pulled the heads sent them in for a rebuild this fixed the comp probem.

    I had some weak roller lifters in the motor so we pulled them out and swapped them with a good used set we had on hand, prefilled all lifters with oil.

    fired the motor up all the codes gone except 0300, truck still ran rough, drove it on the road at 45 CES still blinks. Got home it threw the 1345 cam sensor code not in sync with crank. Only once!

    We reset the distributor ran worse, put it back and it runs just like it did before we fixed the intake and head problems.

    My question is could it be a bad Distributor? what are the odds of that? something else with timing maybe? Going to try setting the Distributor one more time this eve, what would ya'll look at?

    Sorry for the long post, Thanks for any help, I am at a loss on this one.
  2. auzivision

    auzivision Rockstar

    coils, plugs wires are a couple things that come to mind.

    I can’t imagine a distributor going bad. It only performs one function; that is to connect the coil to the appropriate plug at the appropriate time. Unless it is cracked, has water inside, or bad contacts… there isn’t much to fail on a cap. The electronic ignition controls the actual “timing”. Not like the old days where a mechanical adjustment changed the timing (points/condensers).

    from a google search:
    0300... What does that mean?
    Basically this means that the the car's computer has detected that not all of the engine's cylinders are firing properly.
    A P0300 diagnostic code indicates a random or multiple misfire. If the last digit is a number other than zero, it corresponds to the cylinder number that is misfiring. A P0302 code, for example, would tell you cylinder number two is misfiring. Unfortunately, a P0300 doesn't tell you specifically which cylinder(s) is/are mis-firing, nor why.

    Symptoms may include:
    • the engine may be harder to start
    • the engine may stumble / stumble, and/or hesitate
    • other symptoms may also be present

    A code P0300 may mean that one or more of the following has happened:
    • Faulty spark plugs or wires
    • Faulty coil (pack)
    • Faulty oxygen sensor(s)
    • Faulty fuel injector (s)
    • Burned exhaust valve
    • Faulty catalytic converter(s)
    • Stuck/blocked EGR valve / passages
    • Faulty camshaft position sensor
    • Defective computer
    Possible Solutions
    If there are no symptoms, the simplest thing to do is to reset the code and see if it comes back.
    If there are symptoms such as the engine is stumbling or hesitating, check all wiring and connectors that lead to the cylinders (i.e. spark plugs). Depending on how long the ignition components have been in the car, it may be a good idea to replace them as part of your regular maintenance schedule. I would suggest spark plugs, spark plug wires, distributor cap, and rotor (if applicable). Otherwise, check the coils (a.k.a. coil packs). In some cases, the catalytic converter has gone bad. If you smell rotten eggs in the exhaust, your cat converter needs to be replaced. I've also heard in other cases the problems were faulty fuel injectors.
    Random misfires that jump around from one cylinder to another (read: P030x codes) also will set a P0300 code. The underlying cause is often a lean fuel condition, which may be due to a vacuum leak in the intake manifold or unmetered air getting past the airflow sensor, or an EGR valve that is stuck open.
  3. ejohnson03

    ejohnson03 Epic Member 5+ Years 1000 Posts

    My distributer failed at 195,000 miles.
    New dist, plus wires coil, cap and rotor, runs like it is new.
  4. GMGUY

    GMGUY Member

    Timing chain?
  5. vicar75855

    vicar75855 Rockstar 100 Posts

    The plugs cap rotor and wires are all 3 months old. I used autolite 605's for the plugs Ac Delco for the cap and rotor, and a good quality set of wires. we put the spark tester on the wires and we are getting spark, truck just acts just like its out of time.

    Yeah the comp does the timing on this truck, and I only have the single coil, not the multi/one per cyl set up.

    Timing chain might be a good suspect , maybe the cam sensor?? how would you test a Distributor anyway?

    Thanks for the replies folks keep em coming!
  6. MrShorty

    MrShorty Epic Member 5+ Years 1000 Posts

    I don't know how you are "resetting" the distributor. Standard protocol (especially in a case like this where the timing is in doubt) is to hook up a scanner that is capable of reading cam retard (the low end scanners won't), and adjusting the distributor until the cam retard is reading 0 +/- 2 degrees.

    One semi-common failure I see mentioned is the distributor gear. When you had the distributor out, did you look at the gear to see if it looked worn or chipped?
  7. vicar75855

    vicar75855 Rockstar 100 Posts

    Yep we looked at the gear, it looks good to me, no chips or nicks and appears to have been running true.

    Sorry about the terms we are going to pull it out and make sure its in the right spot one last time.

    When we start it is seems way out of time I mean it actually goes clunk, other times it fires right off just misses very bad. The timing chain suggestion didn't sound bad what do ya'll think or am I just grasping at straws...... it did act very similar before we did intake/ and heads.

    I mean could the distributor affect it that bad? This is the first distributor problem I have ever had, other than replacing a worn rotor. So I am learning as I go.

    Thanks for your replies and your patience.
  8. murdog94

    murdog94 Epic Member 5+ Years 5000 Posts

    Did you check for play in the bushings of the distributor? Because i have had several to replace and there are a few threads talking about this where the bushings went out and caused a random cyl misfire, as well as rough running etc.. Also is it running lean or rich? Because FPR can cause symptoms, as well as the IAC being stuck (i know small and simple part im just trying to help) open closed can cause a similar problem.
  9. vicar75855

    vicar75855 Rockstar 100 Posts

    No Murdog I didn't check the play in the bushings! Dang I will look at that and hunt up the threads. It was running lean but that code went away when we replaced the intake gaskets. thanks again for the replies, gives me something to look at.
  10. vicar75855

    vicar75855 Rockstar 100 Posts

    We replaced the FPR while doing the intake gaskets that may have fixed the lean codes we originaly had. Until your post I had not thought of that lol

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