6.2 suddenly smoking bad after cold start ,and misfiring..

Discussion in '1982-Present GM Diesel' started by diesel4me, Jan 19, 2019.

  1. diesel4me

    diesel4me 1 ton status Premium Member

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    I have maintained this thing as well as any other gas powered truck I've had,and spent hundreds more on it,trying to keep it able to start in the winter by replacing numerous glow plugs,buying anti-gel and injector cleaner,and the fact I'm unfamiliar with the 6.2's as far as never having replaced a water pump--- (which looks like NO fun,set up like a Caddy or Buick with long thin bolts that will probably bust off in the block),and me not ever having replaced an injector pump, makes me unwilling to learn how too now,even if I could bend over under the hood for hours and do it.

    I just assume keep the diesel in it,IF I could keep it going "economically"..which is a myth in my opinion,when it comes to a 6.2..the one in my truck has never gotten over 15 mpg no matter what I do with it,empty,loaded,plowing,etc..its just a 3 ton ingot..
    You cant expect miracles as far as mpg with 6.250 lbs empty,to haul around.

    I have had SBC and BBC powered square bodies that did as well as far as MPG--even if I got only 12 mpg I'd be ok with that--I do not go far very often....diesel fuel costs at least 50 cents more per gallon here also,it has topped $4 a gallon in the past--now it's about $2.85..Gas is only $2.35 ..so you don't "save" much there..

    And if you run out of GAS,you just dump in more,and crank it over for 10 seconds and it starts right up again..no bleeding,no dead pair of batteries,no potential starter frying involved..

    But with the cost of something like an injector pump being $500,more than the truck is probably worth to anyone but me,I cant see dumping that much money into a potential pile of scrap iron if it decides to grenade shortly afterwards..


    Other stupid little items on the 6.2 are ridiculously expensive and hard to source..a CDR valve is about extinct now,if you do find one for sale its close to $100--same deal for the VRV valve that controls the vacuum to the TH400 modulator,and the vacuum pump on this thing has failed repeatedly,one I got from a member here lasted the longest,those are also well over $100..

    The HPCA switch on the IP is also over $100..and few used ones are available,salvage yards wont "break up" parts off a running 6.2 and the few I've seen in boneyards are picked clean,probably before they got hauled in..

    I also have not done much more than put glow plugs and filters on this thing,I'm scared to touch the injectors due to the lines being rather flaky and likely to twist off--I have some spares a member sent me a few years ago,but I'm not going to be able to climb up into the engine compartment to install them..so I drive with the fear one might spring a leak someday..I coated them with grease to delay further corrosion..

    The oil pan has been rotted out and patched up for years with fiberglass bondo and RTV, I have 2 good used pans on hand,but cant lay under it long enough to try replacing it..

    The exhaust manifold on the passenger side now has a rot hole in the center section..that is a miserable suck pill to change,I have never fully recovered from having to torch and sawsall the drivers side one off 2 years ago..and it was a good thing I had a blown up parts motor,because those manifolds are hen's teeth in salvage yards and if you see a new one online,they sell for over $400..

    I'd yank the engine out rather than lay over the fender or under it for days trying to install those parts--and likely be unable to succeed in doing it..(Pulling the engine may not be possible in my condition now either,but it would still be less work and make those repairs easier with it out )...but if I took it out,I'd be very tempted NOT to put it back in..

    I've had small blocks apart down to bare blocks several times,I know them inside and out,and being familiar with them makes me much more confident I can fix "everything" on them..the water pump and timing chain can be done in an hour or so,try that on a 6.2..bet the pump costs triple for the diesel too..and the one on mine could fail any day,its been on it the 16 years I've had it,it might even be original..

    Take the truck to any of the garages here and they cringe,and give you a outrageous "estimate" because they want no part of working on a 35 year old truck with a "rare" diesel that has a lot of rot and rust..so I have to deal with fixing it myself,and am less able to with each passing year..

    I have had probably a dozen trucks with small and big blocks and I didn't have any real issues with them,and I used them to commute 70 miles to work & back daily..carbs don't bother me a bit,I prefer a hand choke and do not mind sitting a few minutes after a cold start to let it warm up..carb icing was an issue at times,but I was able to deal with that ..as for EMP's,I have point style distributors..they may not work after one,the diesel may have the advantage there..but that is probably not going to happen ..

    I do like the diesel's throttle response and how it runs (or used to) after a cold start,no choking ,no hesitation or lean spit backs taking off,but all the other disadvantages to me make it not worth having..

    The lowly 307 engines I have with dinky 2 bbl carbs are rated at 200 HP--the 6.2 is 140 HP...torque on the 307 is 300 ft/lbs,the 6.2 is lucky to make 240 ft/lbs..though the diesel makes that torque at a much lower RPM that the 307..
    The truck probably has low enough gearing to not make much difference as far as plowing goes,I've had 305's and 350's that had no trouble at all,in high range,with 3:08 gears..I find a weaker engine and high gears actually plows better ,it cant spin the tires as easily..

    I'd be happy with a straight six too,it would be sufficient for my uses,but trying to find any here is difficult..most got thrown away in perfect condition to swap in a V8 decades ago..wish now I had hoarded the ones I had given to me that ran perfect now..

    I have not changed the air filter on this truck in a long time,but unless its full of mice nests or nut shells,it should be fine,I've only driven it about 5000 miles since it was replaced..I will take a look at it just in case..
    If may just be a rubber fuel line has collapsed or some other fuel related issue ,like water,jelling,or a blocked up fuel filter,dying lift pump (another S-O-B_ to replace!)..I don't know..
    I'm just hoping to keep this thing limping along until spring when the weather is warm enough to tear it apart,I will probably be putting my van back on the road,or buy some other daily driver to use while its apart..unless someone makes me a decent offer for it as-is..
    I'd rather keep it in a way,its emission exempt being so old,no computers,sensors or check engine lights or other BS to put up with..
     
  2. yellowK20

    yellowK20 Well Lubricated Premium Member GMOTM Winner

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    I know you think that your 307 makes more power , but I promise you it doesn’t.
    You do understand the difference between gross horsepower and net horsepower right??

    The highest horsepower 307 was 200 hp GROSS the exact same engine made 130 hp NET
     
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  3. diesel4me

    diesel4me 1 ton status Premium Member

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    I wouldn't expect it to be a powerhouse or even as torquey down low as the 6.2 is,but it'll be sufficient enough for my needs..
    I bet it would not bog down on hills as much as the 6.2 either..
    You can wind up a 307 a lot higher than the 3600 rpm redline the diesel peaks out at too..

    A SBC will start with ONE battery too,in the coldest weather we get here,without needing $80 worth of glow plugs and fuel additives,or a block heater..

    I have a 307 in my G-10 van that's from a '73 Chevelle,the lowest rated HP version with EGR,only year a 307 had it,and the last year they made them..its only a 115 HP "net" rating,230 ft/lbs ,but it was still an improvement ,however slight,over the 250 six I should have left in it,there was nothing wrong with it..the van has 2:73 gears too,which does not help,but the 307 pulls it around OK,and gets the same mpg,15 or so ..the six had better low end torque,but had no guts when you wound it up..nearly the same HP and torque specs of a 6.2..

    A friend has a 305 he pulled from an '86 Monte SS that came out of a '91 Firebird with TPI,that he's replacing with a warmed over 350,I could get hold of that real cheap probably too,the longer stroke of a 305 is a bit better than a 307,but not enough to justify rebuilding it..

    I know that engine ran strong,but the car sat 15+ years in a barn,and suffered for it..
    He pulled the heads off it and found a lot of carbon chunks had come loose,and some mice left nut shells in the intake,some made it into the cylinders,but didn't do any damage,just stuck a few valves open..
    I bet just freeing up the valves and putting the heads back on it would get it running decent again..

    Back in 2003 when I first got this truck in not running condition,I was very tempted to just buy a new "Mr.Goodwrench" 350 for $1500 at the dealer and swap that in it,then I'd have had a dependable drive train I could trust on long trips and no worries..but I was talked out of that by several people,I wish now I hadn't listened to them..truck is now not worth investing that kind of money into it..most anyone else would have just scrapped it long ago..my regrets about selling or parting out the other trucks I had make me hesitant to let this one suffer the same fate..I cant buy one equal or better than it for less than $2,000 around here any more..
     
  4. yellowK20

    yellowK20 Well Lubricated Premium Member GMOTM Winner

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    It’s not worth fixing because you haven’t maintained it , in 300,000 miles I have done a thing to my engine except change the oil and replace the harmonic balancer ( only as preventative measure) and at 75.00 it’s been cheap insurance.

    The 6.2/6.5 doesn’t “need” fuel additives but I do it as preventative maintenance , let me know how your old 307 2bbl like ethanol gas !

    Diesel is cheaper here , on top of that I can filter my used oil and put it in my tank at a 30/70blend for summer use (anymore then that and it’s smokey).

    No to be fair , my truck does have a turbo . But I have 2 burbs and 1-crew cab and 1 single cab 1/2 ton with N/A 6.2’s they all run like Swiss watches and they all get better mileage and comparable power to 350 TBI engines
     
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  5. diesel4me

    diesel4me 1 ton status Premium Member

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    You just want to argue evidently,I told you I have taken as good care of the engine as any other I've owned,probably a lot more!....the engine came from a junkyard before I bought the truck too,so who knows what abuse it had before I ever saw it..
    I was told it had only 80K out of the donor truck..whether that is fact or fiction I cannot say..it sounds a lot noisier than the 6.2 in my Suburban,so I'm betting it had much more than that on it..(the burb has 155,000 on it)..

    You have done nothing to yours in 300,000 miles other than oil changes and a harmonic balancer ?..what about the injectors,glow plugs,you cant tell me the glow plugs lasted 300,000 miles in Alaska!..mine rot away in 2-3 years..sounds to me like that is lack of maintenence..

    I'd also never risk putting anything but good clean pump diesel in mine,using anything else would just be risking trouble with the IP and injectors in my opinion..if I were as cheap as you make me out to be I'd be running it on anything that would burn,but I'm not willing to ruin the IP and gunk up the whole fuel system to save a few bucks on fuel..it wouldn't be worth it to me--not when a stupid fuel filter alone costs $30..

    You have been very lucky with your diesels,good for you..
    I'm not too fond of them,and I'm just tired of having to put up with the 6.2's quirks and never feeling I can trust it not to fly apart somewhere far from home after 16 years..if I lived where you do,I'd never want to trust my life to a 6.2,nor would I want to be a soldier in combat who needs to trust one to get him out of a bad situation..
    I feel I risk my life every time I go anywhere in the truck,especially in severe cold or snowy conditions..never know if its going to grenade or shut off due to a fuel issue--bad enough the rest of the truck is no prize..

    The old carbed gas engines run fine on ethanol fuel as long as you dont let them sit for months too..yes,it sucks compared to the old leaded fuel they were designed to run on,but I'm sure for the amount of time I'll be running a gas engine I'll make out just fine..if I had to rebuild the carb every so often,no big deal..I'd rather do that than replace an IP for $500+ bucks ,and still fear it may not hold together..
     
  6. yellowK20

    yellowK20 Well Lubricated Premium Member GMOTM Winner

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    I grew up in the salt , wash your shit and it won’t rot out .

    Yes , original glow plugs on the original glow plug controller . AC Delco 60g’s

    I got rid of the brick filter and went to a spin on filter , filters are 10.00 and I change them every other oil change (oil changed @5000 miles)

    I would trust my truck to drive all the way to wear you live and back without issue , I routinely drive it during the winter to remote areas in temps reaching down to -50

    The military has put 1000’s of 6.2/6.5 through the ringer over the last 35 plus years . I HAVE had my life depend on a 6.2/6.5 and so have many of my friends .

    It’s not the 6.2 is the problem , it is lack of maintenance and your own unwillingness to learn . You have had that truck 16 yrs , you have done next to no maintenance on it . You put crappy tires on it , crappy mismatched batteries . The truck was already in poor shape when you got it. I’d say to done you pretty damn well .
     
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  7. K5wrench

    K5wrench 1/2 ton status Premium Member

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    :popcorn:
     
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  8. diesel4me

    diesel4me 1 ton status Premium Member

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    I'm not complaining I didn't get my moneys worth out of the truck or the engine,believe me..I'm not going to argue some 6.2's don't last a long time or are "dependable",I just don't trust mine much..after seeing several around here break cranks or blocks without any abuse or warning,I feel their "bad reputation" is deserved..

    I agree for what I've done with it,and TO it,it has held up pretty dam good,but I'm just not a big fan of the 6.2's ,never was really..
    It was in the truck when I got it,and after I got it to run,I figured I'd just run it till it peuked and deal with an engine swap later if I had too..it has lasted 15 years longer than I thought it would,but then I've put only about 10,000 miles on it too in that time span..

    At first I was pretty impressed with the 6.2--it was "different" and it wasn't until I had to put 3 starters,three sets of glow plugs,and the other typical 6.2 issues,that I began to sour on it..
    I loved the VW Jetta diesel I had..that had its downsides too,but it got 50+ mpg and ran smooth ,rarely ever gave me any grief..

    One night I came close to running the truck out of fuel,because the area I was in only had like 3 gas stations that sold diesel--and the only one open was on the farthest end of town away from my location..yeah,my fault for letting it get that low,but that is another nail in the diesel's coffin far as I'm concerned..you cant always find diesel everywhere around here,especially after dark..

    I'm getting too old to do my own repairs and it's not that I'm unwilling to "learn",I just cant do what I used too in the past..just sitting here typing is extremely painful, never mind crawling around under a truck..

    I need something easy to work on,and doesn't have an issue very often..an old straight six or V8 would suit me just fine..Hell,I can barely change a flat tire myself now,without messing myself up bad..
    I was diagnosed with a heart condition recently,so I need no more drama or anxiety,or any roadside breakdowns if I can help it..

    If I were well off,I'd have put brand new tires and batteries in it,and kept it in the garage more,instead of outside,but it was already pretty ripe when I got it..considering how long I let it sit idle outside,it hasn't rusted all that badly since I got it--not compared to the Suburban,which was in excellent shape body wise 10 years ago,it was never registered or driven since in salt,,but it still has rotted badly now,the rockers are gone,and the door bottoms are blistered and ready to come apart..

    The bottom line is I dont need a diesel,don't really like them due to all I've listed previously,and would be better off with a gas powered truck..but for the time being,I have to keep this thing running,and able to get me around town to doctor appointments and get food..
    I'm very glad I don't live where it gets to -50..your a lot braver and luckier than I am ,I'll say that for you..you like your 6.2's and have had good luck,I'm happy for you..
     
  9. campfire

    campfire Adventure is out there! Premium Member

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    I have no interest in the opinion shoving, but I do want to correct one thing:

    It is fairly easy for an IP to inject too much fuel, if someone has been messing with it. Moreover, a simple bump in timing in either direction will create black smoke and power loss (and change the sound, too).

    I don't think Bob's truck has either of these issues, but I don't want you to think that black smoke is impossible on a 6.2. It's very possible.
     
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  10. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

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    OK, a bit of a pissing match here...

    I'm going to inject one thing into the conversation. Gus, you got your diesel truck in good condition obviously, and have worked to keep it that way with proven methods. Bob, got his diesel's in "end life" condition and has not had the money or expertise to reverse that and get them to a point where easy, regular maintenance will keep them up.

    I don't think we need to get all judgey with Bob. When you start with garbage, it is really hard to overcome that. Especially on the corrosion side of things.

    I did the 6.2 thing in '02 and ran that happily until about 2012. Initially with the swapped 6.2 in my Jimmy, then further with the 83 6.2 diesel pick-up I bought from Can Can in 07. For that 10 year period of time the 6.2 made sense for my use. Times change, 6.2 stuff is harder to find now, aftermarket is pretty thin now too, diesel fuel here is about 30% more spendy. One thing posted I am amazed by is the glow plug thing. I ran AC60G's on a push button, Autolite 1110's on the same push button. I'd get maybe two years, then they'd start to fail one at a time. In my stock 83 pick-up with the stock controller I tried the AC60G's. it would not start at all. I installed Kennedy quick heats and liked them just fine...but a year or so later they began to fail one at a time.
     
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  11. campfire

    campfire Adventure is out there! Premium Member

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    60G plugs are slow-heating plugs. Pairing them with an early stock short-cycle controller isn't going to let them get very warm. There's a reason that GM changed the cycle times on later GP controller iterations.
     
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  12. yellowK20

    yellowK20 Well Lubricated Premium Member GMOTM Winner

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    My truck has 680,000 miles , It started out life at a remote mine in Nome Alaska .

    It’s been back and forth to the lower 48 pulling heavy stock trailers.

    And let’s not forget I got this truck after it had litterally been stolen and set on fire .

    Since then it’s been wheeled hard and driven from one end of this state to the other . It’s been exposed to salt water , and I plow with it .

    I promise you I have not spent much money on this thing , oil changes and the occasional hose down .
     
  13. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

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    Yes. it was an experiment because I had them already. I was going to do the push button thing again, but the truck was so original and unfucked with I went with the Quick Heats instead.

    Gus, all bullshit aside I think even you have to agree that your experience is not the common 6.2 experience. For most of the rest of us the 6.2 is a PITA anymore and the common fail points are not especially cheap. Starter prices have come down, but there was a time they were super spendy. Glow plugs, injectors and pumps...and in NA form a pretty underwhelming return on investment.
     
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  14. yellowK20

    yellowK20 Well Lubricated Premium Member GMOTM Winner

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    This is just one of my fleet , and I have had many others that I have sold . Some N/A some factory turbo , and some are banks equipped .

    My current 6.2/6.5 fleet :

    90 V3500 “smokey”
    83 burb
    91 burb on rocks
    91 burb
    91 V3500
    93 K2500
    93 K3500
    94 Blazer
    83 K10

    Every one of them could jump in and drive daily, well not the Rockwell burb but the others good to go . .

    I drive Smokey the most because it’s the one I like the best ,
     
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  15. yellowK20

    yellowK20 Well Lubricated Premium Member GMOTM Winner

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    Humvees and CUCV’s , if you seen how they are treated you would be a believer. The reliable 6.2 is the norm , not the exception.
     
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  16. KirsL

    KirsL Diesel maniac Premium Member

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    Exactly, if GM and the government didn't trust it to do its job. Another engine would of been used. But countless number of Soldier and Marines lives have and still do depend on these very basic engines. That is a more telling story then anything else you'll find on the internet.
     
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  17. sweetk30

    sweetk30 selective wrench turner guy Premium Member

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    Just had a 6.2 in my shop @ 55* temp take 5-6 try's to fire off . Yet the second unit sat outside in high 20* temps fire 2nd try and no block heater . Run smother than 1st did in warmer temp shop unit did .
     
  18. yellowK20

    yellowK20 Well Lubricated Premium Member GMOTM Winner

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    Ok , well it’s time to bow out of this thread .
     

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