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Thread: 1979 Scout II 345 problems

  1. #1
    Join Date
    Mar 2009
    Posts
    6

    Default 1979 Scout II 345 problems

    Greetings! I'm new to the International Scout world. I purchased a 79 Scout II about a year ago. I'm very pleased with the original 345 and have no desire to swap out this engine. When I bought the Scout, the 345 engine had a problem. The engine would start up just fine but when you shift into drive and apply pressure to the accelerator the engine wanted to die or hesitate. Sometimes it would die, and sometimes I would have to press down a little more on the accelerator to stop it from stalling. The engine has 123k mi and 727 transmission is in great shape, bands are not worn at all.
    What I have done to try and fix the problem:
    I have replaced the distributor and coil with a NEW Malory setup, and replaced the carburetor with a NEW Holley 670 w/2in lift. The timing is correct, used cylinder 8.
    With the replacement of the above NEW parts, the problem remains unchanged.

    A pressure test revealed 50-60 PSI. (I used two different testers with the same results) I think this is extremely low and requires about 90-110, but have been unable to confirm this.

    If this is to low, do I need to pull and rebuild?

    Overall the engine performs well when driving in first/second/third gear and kick down works the power band beautifully. Only takeoff is the problem.

    At this moment I'm very confused on how to fix this problem.
    Please help, I love my Scout!

  2. #2
    Join Date
    Feb 2009
    Location
    Aiken, SC
    Posts
    2,423

    Default

    You're right, 50-60 lbs of compression is way too low. In fact, I can't believe it would run at all like that.

    When you did the compression test, did you have the throttle blocked wide open?

    More important, what is your vacuum reading at idle, about 650 rpms?

    When you set the timing, how much advance did you give it at idle.

    More important, what is the advance at 2000 rpms?

    What is your idle speed?
    Allan E.
    Curmudgeon Extraordinaire
    Charter Member, Old Hippie IH Club
    Old fashioned binder freak

  3. #3
    Join Date
    Mar 2009
    Posts
    6

    Default Update

    I wasn't doing the compression test right, I have learned and corrected that...now I can report that the compression is 140-170 which is ok.

    The vacuum reading at idle is 700-800

    Timing, advance at idle is 8

    advance at 2000rpms is 43

  4. #4
    Join Date
    Apr 2009
    Location
    Rock Island TN.
    Posts
    31

    Default Just a couple of questions

    Do you mean that your idle is 700-800.
    Vacuum is nomally measured in inches.
    Timing should be 0 degree at idle with the vacuum line disconnected and plugged from the vacuum advance on the distributor. By the way this is a ported vacuum, meaning it should have no vacuum at idle and then come up as the rpm raises, ideally as you open the throttle.
    What distributor are you using? Later, Paul
    Black Smoke Customs is now open in Rock Island, Tennessee. We are addicted to International's and Cummins B series motors. The only thing we don't do is paint and body,,,yet.
    We support ASE Certification.

  5. #5
    Join Date
    Feb 2009
    Location
    Aiken, SC
    Posts
    2,423

    Default

    700-800 rpm at idle is too fast for an automatic. Need to dial it down to 650 and read the timing again, also read the vacuum at that point. There should be no need to disconnect the vac advance for this reading on a 79 scout. In fact, if you do, it should have no effect, because there shouldn't be any vacuum on the advance at idle.

    If you are not getting smog tested, timing on a 345 should be about 0-3 degrees BTDC plus 1.2 degrees for every 1000 ft of altitude at which you expect do do the most driving. 8 degrees is okay if you live at 5500 ft, but too much at sea level. If it pings while trying to accellerate in high gear up a hill (or at all for that matter) you need to back off the timing a bit or switch to higher octane fuel. I used to have to use Premium when I left my home in the mountains and went down to Phoenix, but that was rare enough that I didn't tune for the desert. I just paid the extra 10-20 cents a gallon for gas for that one tank. It made a difference of about 1.5 mpg, which was a substantial savings in fuel in a scout.
    Allan E.
    Curmudgeon Extraordinaire
    Charter Member, Old Hippie IH Club
    Old fashioned binder freak

  6. #6
    Join Date
    Mar 2009
    Posts
    6

    Default Timing is set to 15 and it really moves now.

    I'm using a Mallory Distributor and a Mallory Coil that I ordered from JEGS. I was testing the timing on the wrong cy. I was testing the the timing on cy 7 which is on the drivers side. I think cy8 is on the passager side (found indicatior on the intake) I'm not a gear head at all so I'm just trying to figure this out. I tried the timing on 0 and 3 and basically it ran like crap and had a really bad studdering problem on takeoff and regular driving. I advanced the timing to 15 and now it seems to work. I'm wondering if the Mallory Distributor and Coil and Holley 670 carb would push the timing advance to 15 from the stock 0-3?

    More to follow after I work on it this weekend. Do scout fuel pumps make a noise when they start to go bad?

    Thanks for all the help again!

  7. #7
    Join Date
    Feb 2009
    Location
    Aiken, SC
    Posts
    2,423

    Default

    Quote Originally Posted by tonto View Post
    I'm using a Mallory Distributor and a Mallory Coil that I ordered from JEGS. I was testing the timing on the wrong cy. I was testing the the timing on cy 7 which is on the drivers side. I think cy8 is on the passager side (found indicatior on the intake) I'm not a gear head at all so I'm just trying to figure this out. I tried the timing on 0 and 3 and basically it ran like crap and had a really bad studdering problem on takeoff and regular driving. I advanced the timing to 15 and now it seems to work. I'm wondering if the Mallory Distributor and Coil and Holley 670 carb would push the timing advance to 15 from the stock 0-3?

    More to follow after I work on it this weekend. Do scout fuel pumps make a noise when they start to go bad?

    Thanks for all the help again!
    Hi rpms will advance the distributor timing. Make sure you are at proper idle speed. Slowing down the engine will reduce the advance.
    Direct vacuum advance will give you 15 degrees. Make sure your vac advance line is disconnected and blocked when you check the timing.

    In the old vehicles, pre-smog, that's what you'd do. Then you'd hook the vac back up and the advance would be on all the time. The reason it was set that way is that the most important setting was under load. The vacuum advance is there to RETARD the timing under load, not advance it when you accellerate.

    Later, the vac advance was put to ported vacuum for SMOG reasons, so it would only kick in when you gave it gas, but not at idle.
    Allan E.
    Curmudgeon Extraordinaire
    Charter Member, Old Hippie IH Club
    Old fashioned binder freak

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