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slow cranking when hot

Discussion in 'The Garage' started by akbound, Dec 12, 2004.

  1. akbound

    akbound 1/2 ton status

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    My '78 Buick LeSabre has an Olds 403 c.i. engine in it. For abou the past 2 years it has cranked slowly when hot. I had thought that a remote solenoid would cure it, but I found this on Mad Electrical's site:

    The START'M UP kit will reduce current flow through the lengthy circuit to only 2 amps–then the system will work fine.

    (2) SLOW CRANKING, a gr-r-runt, gr-r-runt. This kit won't fix it! You'll need to work with ignition timing, battery cables, the starter, and the rest of the system.

    That being said, where should I start? I would rather have my fingernails pulled out than to work on electrical gremlins!!
    TNX!
     
  2. rodzzilla

    rodzzilla 1/2 ton status

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    You could back the timing down a little to see. Does your starter drag only when hot? I had a slow starter on my truck that finally died the other day. Did an autopsy on it to find the front bushing was worn out and allowed the windings to drag.
     
  3. Stomper

    Stomper ΜΟΛΩΝ ΛΑΒΕ GMOTM Winner

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    I'd start with the brass starter bushings.
     
  4. 3 on the tree

    3 on the tree 1/2 ton status

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    Used to have a 70 Burb with a built 406. It started fine till I put headers on it, then got the slow roll when hot. I know it was a hot starter cause I could spray it with a garden hose for a minute or two and it worked just fine. I finally found a factory heat shield and put it on , along with some extra insulation, problem solved.
     
  5. kick

    kick 1/2 ton status

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    Yeah that was the fix for one I had.
     
  6. R72K5

    R72K5 Banned

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    i would retard timing a little and then see, IMHO starter heat soak is overrated, of all the vehicles ive had or been around i have never come across this problem ever so id have to say its a very rare occurance, have seen slow hot cranking many times and its always been due to timing being too far ahead,


    hey i had a 77 electra with the 403 they are fun engine, they are heavy but strong and will push anything, so are the 425's in the caddies they are torque monster low RPM, i shoulda kept both, i had a 79 de ville limousine with 425 i played demo derby with it out here on the property with some trees and some other cars i had around, after i pulled it out i put it on a wooden pallet and fired it up and ran it out in the driveway now and then, one of the board members has it in a truck now, both engines seemed stronger than the 73 olds 88 i had with 455 in it, all were great runners, the 455 is in a boat nowadays

    good luck
     
  7. dyeager535

    dyeager535 1 ton status Premium Member

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    I've dealt with this on Olds/403's before.

    There were a couple of problems with mine.

    First off, the negative battery cable was WAY too small from the factory. This is in a slightly newer car, but the cable got hot with very little cranking.

    Along those lines, the starter itself wasn't in good shape either. The small cable, combined with the starters draw, makes short work of the starter...once everything starts to heat up, the starter just won't turn over good.

    The problem with the cables isn't really just a hot start problem though, because the longer you need to crank it, the more heat generated.

    In any case, do you have the factory heat shield that bolts to the block above the starter?

    I'm not sure how effective they are, but GM thought they were necessary, so if you don't have one, I'd try it. 307's and 403's (from what I've seen) use different shields, but the only difference I noticed was the thickness of the 403 shield, the 307 piece was thin sheet metal.
     
  8. akbound

    akbound 1/2 ton status

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    It does have the heat shield in place. Of course it also has the crossover pipe that goes right under the oil pan to keep the oil well cooked.

    I will definately check the timing. I have heard a tiny bit of pinging lately.

    If that doesn't cure it, I will take off the crossover pipe and wrap it in insulation.

    I love the big boat. I bought it in 2001 with 60k miles on it from a little old lady (for all of $1100!). It now has 130k on it. It looks like crap and also goes like it, too! On a straight line it won't burn out from a stop, but it breaks loose at about 15 mph. I also don't get cut off on the highway because people can tell that I just don't care and want them to hit me. I have been driving it alot while I wait for Alaska to send me my oil money so that I can put 300 horses under the hood of the Blazer.

    Thanks for all the help!! You guys rock!
     

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