Ready to burn it...:(

Discussion in '1982-Present GM Diesel' started by diesel4me, Nov 5, 2020.

  1. diesel4me

    diesel4me 1 ton status Premium Member

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    Well,after putting two new batteries in my '82 K2500 (6.2 ),I had a bitch of a time getting it to start ..it's been doing this for awhile now..

    What it's been doing lately is after I turn on the glow plugs for about 10 seconds ,and crank it,it'll fire right up...but immediately stall unless I keep it floored,and let it rev way up (something I hate doing to any engine after a cold start)..it will usually keep running ,like its "flooded",and after 5-10 seconds or so,it'll clear itself out after belching a big cloud out of the exhaust--then I can let off the throttle gradually and it'll idle ,and everything is ok..

    BUT--if it stalls after that first start,it will just crank & crank over even if I re-activate the glow pugs each time,and if I'm lucky,after a LONG cranking,it will start firing like only one or two cylinders are firing,and eventually more & more of them start firing,and it'll finally run,belch out the cloud,and clear itself out--IF the batteries aren't dying by then..(new batteries haven't yet,but I've been careful not to overheat the starter,or let the batteries get weak enough not to crank fast enough lest I kill them dead or wound them permanently)..

    I even resorted to taking off the air cleaner,tried spraying diesel in the intake with a pump sprayer while I cranked it remotely from under the hood,after activating the glow plugs..NADA..thing just cranked and cranked..(This has worked before for me when I ran out of fuel,to get it running long enough to self bleed).

    THEN I took a few pages of newspaper,crumpled it up,LIT IT ON FIRE,and put it in the intake..let the flames get going really good,then cranked it over a good 15 seconds..NOTHING..not even a fart..this tells me the glow plugs must be working,as it would most likely fire right up with a flame being sucked into the intake..

    I then took off the return line hose at the injector pump,after reading the fitting in the pump has a glass check ball in it that can stick,and block the fuel flow,which will stall the engine...took out the fitting,sprayed it with carb cleaner,the glass ball is intact,clean,and the spring was free,so I dount that was causing any trouble..

    Put it back together,got in the truck,activated the glow plugs,and it wanted to fire up right away,and I had to hold it floored,until the thing "cleared out" and revved up,and belched the usual cloud out of both exhaust pipes..(unburned diesel I assume,its not coolant or oil smoke)...

    So I have no clue WTF is wrong with this P-O-S,the electric fuel pump I put near the tank works OK,I open the bleeder on the firewall fuel filter and fuel gushes out when it is on,so I know its not too low on fuel or starving...lift pump is still in the fuel system too,its not leaking either,so I assume its OK...(and it should run on the electric pump even if it was junk)..

    The pink wire on the injector pump makes the solenoid inside click on and off when I pulled it off and put it back on with the key on too,so I assume that is working OK..

    Once (IF) I get the truck started,it'll run all day,and fire up on one turn as long as its still "warm"--it was near 60 degrees out yesterday,so it's not like it was below freezing...
    I'd buy 8 new glow plugs if I thought it would cure this--but I have my doubts seeing open flames wouldn't light it off!..

    After I finally got it to start I left it running about 15 minutes--now I see the oil leak has returned,it looks to be coming off the drivers side head in the rear,possibly between the head & block,or it may just be the valve cover gasket..guess I'll be dumping a quart in (at least) every time I drive it again..

    SIGH....I wish I had the ability to rip this six point turd out and put a gas engine in this pig...after 17 years of it I'm about "done"...I fully expect the starter to crap out next,from all the excess cranking lately too,that'll be the third one ..
    The oil pan should be replaced too,but I am betting if I took it off,I'd find cracks in the block webs--or have the crank snap a week later if none are apparent,with my luck..:surepal:

    Anyone have any ideas WTF is wrong with it ?...could a slow drippy leak at the bottom of the fuel take let air get sucked in the fuel lines overnight ?--if so,then why does it fire right up,THEN stall,instead of having to be cranked excessively to bleed the air out?...I'm pretty much stumped..


    Like I said...READY TO BURN IT!..:angry1:
     
  2. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

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    All it takes is a small fuel line leak and it will do exactly what you describe. The leak can be small enough to not even drip, just enough to allow some air into the system. My theory on it lighting off but needing revs at first is there is fuel at the injection pump, but air behind that. 6.2's don't "self bleed" worth a shit. I'd take a long look at the supply line to the IP. It likely isn't any of the individual fuel lines...
     
    campfire and red EOD like this.
  3. diesel4me

    diesel4me 1 ton status Premium Member

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    I ran 3/8" copper tubing in one long length from the electric fuel pump next to the fuel tank to the firewall fuel filter (its a 33123 Wix can style),and used new short pieces of 3/8" hose with double clamps to plumb it to the pump & tank sending unit...pretty sure there is NO air getting in there,unless maybe the sending unit feed pipe inside the tank has a rot hole in it or something,and even then it'd only let air in if the fuel level was below it..

    I would think the electric pump would pressurize the fuel lines enough to show up any spots that would let air get in..

    The fuel hoses from the firewall filter to the lift pump and injector pump aren't new,but aren't showing any weepage either..

    I doubt replacing them will improve anything,but I probably should anyways,especially the one that goes under the intake to the injector pump,that one was there when I got the truck back in '03...its only a 1/4" hose too,so I had to use a pair of barb fittings to reduce the 3/8" line off the filter to connect them together--that's air tight too,I used thread sealant on the fittings..double clamped everything too..

    One place that might be suspect is the throttle shaft bushings on the injector pump--the valley under the intake does seem "wet" but it is most likely motor oil from the CDR plumbing or a valve cover weeping..
    I've read if the seals there leak it'll cause similar symptoms,amd some have rigged up a "priming bulb" off a boat tank to the return line,using clear hose ,so you can pump the bulb until fuel is showing and no bubbles are in the line--then it'll fire right up..old VW diesels could be jerry rigged that way and driven many more thousands of miles without having to replace those seals..

    I have no problem doing that IF it'll solve this issue..

    What gets me is it seems to be getting plenty of fuel,maybe too much,judging by how much excess fuel gets blown out the exhaust when it finally start..

    BUT If this thing ends up needing an injector pump or a water pump--its getting ripped out and replaced with some other GAS engine that will start in winter...far as I'm concerned diesels suck for a plow truck,nothing but grief getting them started ,even if you use a block heater,have all the glow plugs working,at least in my experience with this p-o-s..

    I'm not willing to kill myself bending over for a day or more to replace either the water pump or injector pump on this engine,or lie under it trying to put a better oil pan on it ,when it may have a massive failure a week later..it's not worth it..
    If it leaves me stranded and needs a tow home,that'll be the last straw for the 6.2...

    I'm already sick with a runny nose and sneezing now,my sinuses are fuct from spending all day sunday out in the damp chilly weather trying to ghetto fab a battery tray to mount the battery on the passenger side,its a nasty head cold type crap..hoping its not covid...

    Now it's supposed to be near 70 daily till next Wednesday,and I'm feeling too sick to go outside any do anything..

    The truck still needs a new fuel tank and that rear spring hanger replaced,this would be the perfect time to do those miserable jobs and weld up some spots on the frame,it'll be the last chance before the weather really sucks here..(It already snowed 4" last week here)..

    What really pisses me off is I have saved up about 3 grand and have looked at several trucks for sale under that amount both online locally and at used car lots nearby,every one of them have at least some frame or cross member rot,or 300,000 miles on them,body rot,or have a check engine light on.
    One truck that was "nice" I found out had a title problem,so its "parts only"..--even when you have cash to buy something around here,there's nothing any better than what I have now for that price..
    I just assume put the money in this truck than buy another bigger headache..
     
  4. 6.2 man

    6.2 man 1/2 ton status Premium Member

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    Something that could be happening is the return valve on the Injector pump is screwed up . This will allow fuel to return to the tank faster than it's filling the pump . I take some pliers and pinch off the return line and try starting the engine .
     
  5. diesel4me

    diesel4me 1 ton status Premium Member

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    I'll try that next time it either doesn't start,or stalls after the first cold start..but the glass check ball was clean,not sticking,and the spring if anything seemed to have a lot more tension than I thought it should--I could not blow thru the valve by mouth,but carb cleaner passed freely thru it..
    I also want to put clear hose on that short return line so I can see if any bubbles are showing..(not sure if ordinary vinyl hose will stand up to diesel fuel or not)..

    Past 2 days its been near 70 degrees and it fired up OK,I kept it at a fast idle (not floored like I had to before) and it quickly cleared out and was able to idle without stalling..drove fine the 10 miles I went in it too..
    I'm going to do the test light check of the glow plugs,it may have some dead ones by now..rather replace them now than in the dead of winter..

    I may be brave (or dumb) enough to risk taking a 25 mile trip each way in the morning to the flea market,it is only going to be open maybe 3 more times before closing up for the year,and its supposed to remain in the 60's here till Wednesday,it'll likely be the last "warm spell" we'll have (We got 4" of snow Oct 30th!),so I'd like to make one last trip there.....
    But if I end up getting stranded in it,I will probably be pissed enough to do something drastic,like rip out the diesel,or sell it,maybe even scrap it...my ability to work on it is about over,so is my patience..

    I lost the headlights on my way home tonight,at 5 pm,had to use the plow lights to see!--I may have left a ground wire off when I replaced the batteries or one came off,I suspect its a ground issue because one hi beam and low beam were coming on with it on low beams,dimly,back feeding..:screwy:--or maybe the connectors at the bulbs are gangrene again....that will of course entail removing both batteries again,to get at the wires..:angry1:...love the way everything works great in July when I had to pass inspection,but as soon as November comes,everything starts effing up royally..:mad2:
     
  6. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

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    Do you still have the square filter on that truck, or canister filters? I seem to recall those square filters could crack the housing and allow air into the system...
     
  7. diesel4me

    diesel4me 1 ton status Premium Member

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    Round canister ,that takes a WIX 33123 spin on filter with a drain valve on the bottom..

    Truck started right up today,drove it 50 miles round trip--for nothing..
    Went to the flea market,that said was supposed to be open today on their FB page at 11 last night,it was supposed to be a beautiful 70 degree day,so I decided to risk one last trip there before they close up for the tear..
    I get there,and the place is deserted!...guy working there told me "a state cop came here at 4 am,showed me an "official notice" from the governor--"due to covid increases we have dropped back to phase two"--which means no "crowds" over 50 outdoors !..

    Man I was pissed!..risked my neck for nothing..:mad:

    I smelled diesel all the way there too,but as my luck goes,when I went to add $10 to the tank to ensure I'd not run out today--the dam thing overflowed when it hit $7!..my gas gauge doesn't work,and keeping track of the miles doesn't always ensure you'll not run it low,because I let it run sitting still lately ...lady at the gas station just shrugged when I told here some spilled,which I was glad of.."Not my problem"!..

    I drove off with diesel streaming off the tank...so I figured that was the cause of the odor..

    When I got home I investigated the diesel smell--turns out the hose I put on the injector pump return was almost all the way off!--some had spilled into the valley under the intake..I was able to shove it on all the way and tighten the clamp..

    I then spent the next 7 hours dismantling and rebuilding the headlamp buckets,had to fudge some Ford adjusters onto the radiator support,solder one lug back on a headlight,braze up the rust holes in the buckets before the screw tabs tore off (had to use my jewelers torch to heat up the screws to get the retainers off too)--as usual I touch one thing and 10 more things turn to :poo:..

    Last night halfway home I lost all 4 headlights,luckily the plow lights still worked OK..:mad1:

    I had to add a ground wire to the passenger side lights to get them to work,they were back feeding weird,one hi beam and a low beam came on with the high beams on dim,like candles..
    I thought I left off a ground wire when I replaced the batteries last week,but they were all still connected..I guess the lights just wanted a better ground ..:what:
    Thankfully I got them working right again,and used a dremel tool to wire brush all the headlamp plug wires...they were very green,despite some boob using chassis grease to "lube" the plugs,like a pound of it..(not me,I use never-seize!)..my hands were black as coal after that job,and sticky..

    Oh yeah..while I was in the quonset garage brazing up the headlamp buckets--a 4.0 earthquake occoured!..:ooo:

    First I heard what sounded like the rumble of a hundred chopper motorcycles,or a train going by ,then the building began "drumming" with vibrations,and the overhead door started bouncing against the tracks,like a strong wind gust hit it,or someone was pushing on it outside..it lasted about 10-15 seconds and was centered in a town about 20 miles south of here..

    This was the second time I was in the garage when we had a quake,last one was only a 2.0 ,so it was no biggie..this one started to get scary!..

    I'm too dam sore to do any more to the truck today,and there was only an hour of daylight left anyways..wanted to test the glow plugs,but my back pain is off the scale ,I couldn't bend over that long..
     
  8. BadDog

    BadDog SOL Staff Member Super Moderator Author

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    My C10 has done that for a while. Including sometimes exhibiting no problem at all.

    I suspected an fuel/air leak near the motor, but checking/replacing just didn't fix the problem. Recently it started leaking from the throttle shaft (rebuilt ~6 years ago), so my current assumption is it's been getting air in the pump when setting, only recently getting bad enough for fuel to leak noticeably under pressure.
     
  9. diesel4me

    diesel4me 1 ton status Premium Member

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    So far the truck has started right up and I was able to let it return to idle almost immediately without it stalling,I drove it 50 miles non-stop Sunday (as I explained above) ,it never missed a beat..
    I used the truck at 6 am this morning to go get groceries and it was about 50 degrees and pea soup fog,but it fired right up and didn't stall,and again,no problems on that 12 mile round trip..
    It only sat all day yesterday,so maybe that was not long enough for air to sneak in somewhere..

    I won't doubt the injector pump may get air bound if I let it sit several days--I cant see the throttle shaft seals too good,the valley is "wet" but the short return hose on the IP was not on far enough and it was dripping there Sunday till I got the hose on all the way and clamped it better--the hose I used was hard and didn't want to go over the barb fitting..after it got diesel on it,it softened up enough to push it all the way on..

    Its weird how it'll start right up at first,then if it stalls,and getting it to run again takes a lot of cranking..with both an electric fuel pump at the tank and the stock lift pump ,I would think it wouldn't take long to get fuel back to the injector pump,if it had no fuel in it..but after it finally starts,its like it was flooded,so much unburned fuel and white smoke belches out the exhaust and it runs ragged until it clears out..
    That is why I think the glow plugs may be suspect.

    Since its been "warm" here the past few days in the 70's,not dropping below 40 at night,I am not sure if it could be some glow plugs are dead causing or aggravating this ,but it doesn't really affect it's starting until it gets cold enough out,if more than one glow plug isn't working..
    (Its only had 7 glow plugs since I owned it,one refuses to come out so rather than break it off and cause another major dilema,I just keep 7 working ones in it,and up until now its always started ok with 7)..
    ..
    I'm going to test them all later today if I get to before dark,our warm weather streak is expected to close tomorrow afternoon with rain moving back in..from then on it'll only be in the 50 degree range for high temps ..was hoping to get a new fuel tank and install it,replace the rear spring hanger and weld up some spots on the frame before the good weather ends,but its not likely to happen now..

    I have to wait a day for the tank to come in after ordering it,and now the old tank has at least 16 gallons in it still...could use the electric pump to transfer the fuel I suppose...cant replace the spring hanger till the tank is removed,its right next to it and I need to grind or torch off the rivets..still have a severely aching back from Sunday's headlight repair job too...be lucky if I get all this done before month's end and more snow and freezing temps return again..
     
  10. campfire

    campfire Adventure is out there! Premium Member

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    That is *exactly* what air bubbles do. If you had glow plug problems it would not fire off immediately.

    You can quickly bleed the air out if you loosen each injector line and then crank for a few seconds. But that method just saves the starter, it doesn't save much time (if any).
     
  11. diesel4me

    diesel4me 1 ton status Premium Member

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    I don't dare touch the injector lines ,they are rusted and will likely twist off if I mess with them...

    I have spares,but if I end up having to install any of those I'll be more tempted to just pull the 6.2 out and be done with it...

    If I were in better shape it'd already have a gas motor in it..but as long as the diesel keeps running I'm not going to go taking the truck apart now,too close to winter..need it to plow,and its my only transportation too,so I cant lay it up very long..
     
  12. campfire

    campfire Adventure is out there! Premium Member

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    Find the air leak. Check your copper line carefully. Copper work-hardens with vibration, so it's not a good long-term choice for a motor vehicle. Check the return lines, too. Each injector has 2 return line connections, and those are common leak points. You can buy an engine's worth of good diesel-rated injector return hose from Badger Diesel for about $20.
     
  13. diesel4me

    diesel4me 1 ton status Premium Member

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    I have tygon fuel hose on some of the injector return lines..none of them leak ..
    I have a GM retur line hose kit that came in the Burb when I bought it,but I am going to save it for that truck--they are just rubber hoses too,I like the tygon better,no clamps needed..
    I have used Firestone air brake tubing on the injector return lines before too..

    The copper line is good and not that old..

    I suspect it may be the fuel feed tube on the sending unit ,that may have a pinhole in it--it is original and sat in the empty (dual & unused ) leakytank it had when I got the truck,so it may have rusted ...since I filled the fuel tank full last Sunday,it has started right up and doesn't stall so far at least,but I haven't started it since Tuesday morning..tomorrow I will,and see if it acts up again..

    Edit--I've read on several forums the throttle shaft seals on the injector pump rarely let air get in,they just weep fuel,so its not likely causing my issue,I don't think they are leaking either really..
    The lift pump might be iffy too,its been on it since I got the truck,its not leaking externally,or pumping diesel into the crankcase,but maybe its check valves don't hold vacuum or something..thats another thing I'd hate to replace..
     

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