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6.2's cold starting

Discussion in '1982-Present GM Diesel' started by 86dieselburb, Oct 26, 2004.

  1. 86dieselburb

    86dieselburb 1/2 ton status

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    6.2\'s cold starting

    I recently got myself and 86 diesel burb. Is it normal for these things to be kinda hard to start when cold? I'm kinda new to this diesel stuff and am used to gassers that start right up first time. The overnight temps around here have been getting in the low 40's. The motor has 302K on it but seems to run great otherwise. I have been resorting to turning ignition wait till glow plug light goes out, push gas pedal half way and crank the motor. Seems it takes at minimum 3 tries before it comes to life. Think new glow plugs will help?
     
  2. 6.2puller

    6.2puller 1/2 ton status

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    Re: 6.2\'s cold starting

    I have learned that their are a few keys to starting the 6.2L. One is glow plugs but an even more important one is cranking RPM. The stock starters are pretty weak. An older one is even weaker. When I got my truck it wouldn't start 50% of the time and I instantly thought glow plugs. (I was a gas guy getting his first diesel like you) Reading on here I saw the cranking RPM mentioned alot. I checked the amperage draw at my starter and it was way loaded up and not turning much. So starter replacement was in order prior to glow plugs. A little research on starters taught me that the 6.5L gear reduction starter is the way to go. It bolts on and gives you way more crank for your amp. After replacing that I only did the glow plugs because the looked as old as my truck. The truck started 100% with just the new starter.

    So I would check the glow plugs to make sure they are working (test light between glow plug terminal and the wire that goes on that terminal durring glow plug cycle) and only replace them if they are not working. If they are working look to your starter for your problems.
     
  3. 86dieselburb

    86dieselburb 1/2 ton status

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    Re: 6.2\'s cold starting

    Thanks for the input. Probably would be good insurance to replace the starter anyways. Not sure how old it is anyways. I'll have to keep my eye out for a gear reduction starter.
     
  4. 86dieselburb

    86dieselburb 1/2 ton status

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    Re: 6.2\'s cold starting

    Had another question. Do all 6.5TD's use the gear reduction starter? I was just browsing around some parts store web sites and they don't make any mention of a gear reduction starter.
     
  5. 6.2puller

    6.2puller 1/2 ton status

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    Re: 6.2\'s cold starting

    ebay link That the one I am running. I think they all had gear reduction starters. For the record, I have posted this guys link numerous times but I am not in any way connected to him. I just felt it was a good deal and passing it on.
     
  6. 86dieselburb

    86dieselburb 1/2 ton status

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    Re: 6.2\'s cold starting

    Thank you. I was just looking at that starter.
     
  7. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

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    Re: 6.2\'s cold starting

    In cold weather I usually hold the throttle halfway down...and if it's really cold I hold it all the way down.

    Good GP's, good cranking speed, and if it gets really cold plug in the block heater...and you shouldn't have any starting troubles. With 302K miles on it I'm sure the compression isn't what it used to be...so it may be crankier than the average 6.2 anyways until it warms up.

    The gear reduction starter is often referred to as a 28MT. Most parts places I've used show two starters available for the 6.2 (depending on what year you ask about).

    Rene
     
  8. 86dieselburb

    86dieselburb 1/2 ton status

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    Re: 6.2\'s cold starting

    Yeah it just seems "cranky" when its cold. After its been running, starts up great For having 302K it has great oil pressure, 38psi at idle and near 50psi running. But you may be correct about the compression being low. I was pleased with the performance of it untill I put on a 6 inch lift with 36 inch tires. It's a wee bit of a slug now even with the 4.10's. I live up in the mountains so 45mph is max speed getting up the hill now. Does great on the flat.

    Thanks for clueing me in on the 28MT designation.
     
  9. AgDieseler

    AgDieseler Certified Scrap Producer Premium Member GMOTM Winner

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    Re: 6.2\'s cold starting

    At 301K, my old 6.2L always started with 1/2 turn of the crankshaft - cold or hot. That's thanks to a healthy glowplug system, good batteries, and decent compression. I say decent because I have no real data to back it up, but if you've got plugs that are lighting strong, and a starter that spins well (and assuming your fuel system is in good working order), then solid compression is the only thing left. If you're just going for better starting performance, a head gasket R&R along with a timing set would certainly do the trick for faster given the above parts are met.
     
  10. 86dieselburb

    86dieselburb 1/2 ton status

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    Re: 6.2\'s cold starting

    Well, I know the batteries are strong. I just replaced those when I bought it. I'll try the starter first and see how that helps, then if it still is cranky i'll try the glow plugs. I figure if I need to R&R the head gaskets and timing chain, might as well rebuild the whole motor or replace it. I have a brand new custom FI 454 just itching to go into something. But I like the diesel and would rather sell the 454 and use the cash to rebuild the diesel. Guess i'll just have to tinker on it a bit and see what works best.
     

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