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  1. #14
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    Aug 2009
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    Beatrice, NE
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    I had an issue with my 99 Chevy Express with ta 5.3 V8.

    It would run fine idling but put it under load and it would struggle like going up a hill. It would hit the top of the hill and take off like an anchor was released. My son dug into it for me and found a gear that engages the end of the cam at the back of the engine was worn, badly. Replaced that gear and it ran great again.

  2. #15
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    Let's hope it didn't jump timing. If in fact it did there could be valve damage. Don't know if that engine is a clearance or non clearance type engine. Most likely the latter most newer ones are.

  3. #16
    Join Date
    Sep 2002
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    Thread Starter
    I couldn't think of another option as the distributor rotor was not pointing to the #1 post in the distributor cap - with the timing marks at the crank pulley lined up.

    Although . . . . I have worked on hundreds of engines - most in a former pre-refrigeration lifetime - and never once had to replace a timing chain because it, or it's sprockets, was worn out.

    The 4.3 GM engine is essentially the latest evolution of the 350 small block - just with two cylinders lobed off to make a six. So it's not an interference engine.

    Looking at the timing sprockets and chain last night made me think: "hell; they look perfectly fine to me: zero signs of wear." The cost of replacing them is small but the work of doing it will be huge. The front of the engine is 18" or so from the radiator - and you can't get to anything from under the van - so whatever you do requires full arm extension, while holding your body weight supported/balanced solely on your abs, and having your head lower than your ass the whole time.

    Pondering the timing chain replacement procedure makes me think: damn; that timing chain and sprockets look just perfect! <g>

    PHM
    --------


    Quote Originally Posted by VTP99 View Post
    Let's hope it didn't jump timing. If in fact it did there could be valve damage. Don't know if that engine is a clearance or non clearance type engine. Most likely the latter most newer ones are.
    PHM
    --------
    The conventional view serves to protect us from the painful job of thinking.

  4. #17
    Join Date
    Jan 2010
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    That's a plus
    Attached Images Attached Images  

  5. #18
    Join Date
    Sep 2002
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    Thread Starter
    What do you think of this one?
    ----------------------------------------
    Here is a link to the differences:
    https://www.palmerperformance.com/pr...comparison.php

    This is another link to all the parameters in the GM enhanced:
    https://www.palmerperformance.com/su...m_enhanced.php

    Thank you,
    Sales - Palmer Performance Engineering, Inc.
    sales@palmerperformance.com
    ---------------------------------------

    Under $150. and my thought was that a laptop would be so much easier to see than a phone. <g>

    PHM
    --------

    Quote Originally Posted by tej1234 View Post
    The misfire code cannot come back until the engine is running, and your cranking might not be enough.

    Does your code reader give pending codes? (Codes before they turn on the light.) I use the Blue Driver for my GM cars but there are others.
    PHM
    --------
    The conventional view serves to protect us from the painful job of thinking.

  6. #19
    Join Date
    Sep 2002
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    Thread Starter
    Where did those "interference or not" replies come from?

    What website ?

    PHM
    --------
    Quote Originally Posted by VTP99 View Post
    That's a plus
    PHM
    --------
    The conventional view serves to protect us from the painful job of thinking.

  7. #20
    Join Date
    Apr 2012
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    I have seen the rotor burn a small small hole in the middle and arc down to the shaft..
    I have seen distributor caps go bad to where it arcs to one post each spark due to carbon tracking... Scratchs.. cracks.. so it it trying to fire two posts at once.
    Let's just say the number four post for instance... It will get a spark each time from the crack and the post that is supposed to get the spark only gets limited voltage... That number four now firing random can cause bucking.. back firing terrible idle and so on.
    I first suspected distributor trouble... But I cant get away that the problem began when you had a temporary connection problem at the battery.
    Maybe you just had a terrible day and this problem would have occurred anyway if there had been no connection loss.... In that case with General Motors the problem is often right at the distributor...Cheap rotors used to be a problem (arcing to the post).. but you have spark which can still be a bad cap tracking on the inside.


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  8. Likes CEAS-AC-TECH liked this post
  9. #21
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    Jan 2010
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    Quote Originally Posted by Poodle Head Mikey View Post
    Where did those "interference or not" replies come from?

    What website ?

    PHM
    --------
    That one was SilveradoSierra.com

  10. #22
    Join Date
    Sep 2002
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    Thread Starter
    The entire distributor, including all it's parts, was replaced maybe 4000-5000 miles ago. Not to say that new parts can't also fail - but I tend to look elsewhere for trouble. I guess 60,000 volt ignition is more prone to carbon track but I sure don't see any evidence of it examining the still-new-looking parts involved.

    It's raining today and I have a custom oak railing and balusters to build today (and I Just Now finished just the Pattern for the railing end angles <g>) but since I already have the timing cover off: maybe tomorrow I'll start rebuilding the engine from there on out. Eliminating timing issues as I go.

    After that I'm debating buying a super-duty scanner - or having the SOB towed to a shop and make them find the problem(s). <g>

    Can the computer for this engine (controls the timing and so forth) fail to intermittent? Or is it always good / fully bad ?

    PHM
    --------


    Quote Originally Posted by Missouri Guy View Post
    I have seen the rotor burn a small small hole in the middle and arc down to the shaft..
    I have seen distributor caps go bad to where it arcs to one post each spark due to carbon tracking... Scratchs.. cracks.. so it it trying to fire two posts at once.
    Let's just say the number four post for instance... It will get a spark each time from the crack and the post that is supposed to get the spark only gets limited voltage... That number four now firing random can cause bucking.. back firing terrible idle and so on.
    I first suspected distributor trouble... But I cant get away that the problem began when you had a temporary connection problem at the battery.
    Maybe you just had a terrible day and this problem would have occurred anyway if there had been no connection loss.... In that case with General Motors the problem is often right at the distributor...Cheap rotors used to be a problem (arcing to the post).. but you have spark which can still be a bad cap tracking on the inside.


    Sent from LG Stylo 4 using Tapatalk
    PHM
    --------
    The conventional view serves to protect us from the painful job of thinking.

  11. #23
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    Jul 2010
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    US of A
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    Quote Originally Posted by Poodle Head Mikey View Post
    The entire distributor, including all it's parts, was replaced maybe 4000-5000 miles ago. Not to say that new parts can't also fail - but I tend to look elsewhere for trouble. I guess 60,000 volt ignition is more prone to carbon track but I sure don't see any evidence of it examining the still-new-looking parts involved.

    It's raining today and I have a custom oak railing and balusters to build today (and I Just Now finished just the Pattern for the railing end angles <g>) but since I already have the timing cover off: maybe tomorrow I'll start rebuilding the engine from there on out. Eliminating timing issues as I go.

    After that I'm debating buying a super-duty scanner - or having the SOB towed to a shop and make them find the problem(s). <g>

    Can the computer for this engine (controls the timing and so forth) fail to intermittent? Or is it always good / fully bad ?

    PHM
    --------
    ECM or PCM can be intermittent especially with a bad ground.
    Signature removed Violated rule #15

  12. #24
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    Apr 2012
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    Quote Originally Posted by Poodle Head Mikey View Post
    The entire distributor, including all it's parts, was replaced maybe 4000-5000 miles ago. Not to say that new parts can't also fail - but I tend to look elsewhere for trouble. I guess 60,000 volt ignition is more prone to carbon track but I sure don't see any evidence of it examining the still-new-looking parts involved.

    It's raining today and I have a custom oak railing and balusters to build today (and I Just Now finished just the Pattern for the railing end angles ) but since I already have the timing cover off: maybe tomorrow I'll start rebuilding the engine from there on out. Eliminating timing issues as I go.

    After that I'm debating buying a super-duty scanner - or having the SOB towed to a shop and make them find the problem(s).

    Can the computer for this engine (controls the timing and so forth) fail to intermittent? Or is it always good / fully bad ?

    PHM
    --------
    I am only leading you to the distributor as it is easy to check .. and it not an uncommon problem...You had mentioned backfiring running rough..and an engine misfire code.
    How the misfire code works ..is the computer detects that brief temporary nano second slowing of the engine in relation where the engine is in the fireing sequence...If our engine is bucking.. running real rough ..etc(other than besides a steady miss)..that misfire code may not be accurate..it was just slow enough in the sequence to get (blamed)...but the fact that it tossed one out shows us it is at least running rough.
    I would go straight to basics and work my way up by the trying the following
    I would check ignition timing while cranking..if you are showing a little before TDC you are good.
    You had mentioned a backfire...Timing off very many degrees can cause this.
    Lean fuel mixture can sometimes cause it..and so can arcing in the cap where it is not supposed to be arcing.
    Since the voltage is much higher than back in the old days..arcing is more apt to occur as well.
    As far as the computer ...do it by process of elimination.
    Unplug fuel pump relay...and see if engine will run on starting fluid...is yes ignition is working properly and it is a fuel delivery problem.

    Check timing while cranking...touch before TDC....just for grins...check the opposite cylinder (opposite wire on distributor) while you are there....should also fire just before TDC.
    But don't stop there that cheap timing light can do so much more...If you don't want to replace the cap you can check it with the timing light.. With the other four plug wires...one at a time try them for erratic firing .. they should all fire with the same amount of time in between flashes..a sporadic spark on any of them will point to a cap.
    A good light can find an internal arc too if the tracking is tracking to a post ...as the induction of the light will pick it up and it will be fireing six times more than it should be.

    The GM computer isn't generally a item to fail....but as someone has mentioned... Bad grounds can cause a host of problems

    If it does start...keep it going as long as you can.
    Some problems have to exist a decent amount of time before a code will be set... others a warm engine must present

    A missing engine with EFI will sometimes barely run until the computer figures out that cylinder is missing...reason...the air leaving that cylinder hasn't been (used) the computer doest know that and changes the fuel mixture because it thinks the air fuel mixture is wrong as that is what the oxygen senors are telling it.. that's why if you get it started..run it for several minutes..the computer will figure out whats wrong with it almost everytime..



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  13. #25
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    Apr 2012
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    You can also try a reset... Let's say it was trying to learn... But wasn't done yet... You shut it off... Whilst it was bucking and shaking.. try a reset First... Free and easy

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  14. #26
    Join Date
    Sep 2002
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    Thread Starter
    It was just a straw-grabbing wild-ass guess. I disconnect the battery every time I leave this van alone in Florida for more than a week. And it has never done anything with the battery eventually reconnected but start and run smooth.

    I used to have a Jeep Cherokee that always seemed to require some 're-learning' every time the battery was disconnected. That'
    s what put it in my mind with this van - but this van has never seemed to require it before.

    But while we're talking: how is that "resetting" process accomplished anyway? <g>

    PHM
    --------


    Quote Originally Posted by Missouri Guy View Post
    You can also try a reset... Let's say it was trying to learn... But wasn't done yet... You shut it off... Whilst it was bucking and shaking.. try a reset First... Free and easy

    Sent from LG Stylo 4 using Tapatalk
    PHM
    --------
    The conventional view serves to protect us from the painful job of thinking.

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