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UPDATE 1982 6.2 runs crappy problem need help UPDATE

sweetk30

sweetk30

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a farmer friend of mine has a 82 c-30 with a 6.2 and its been getting worse the more he drives it.

starts up vary hard and blows lots of white smoke from exaust and have to use full throttle basicly to keep it running and it dosnt rev up much.

it almost sounds like its missing a few cylinders firring like a skipping gas motor.

he is thinking the injection pump is on its way out or possible injectors.

i am no oil burrner mechanic. so any help would be great. thanks.
 
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I would also think the IP/injectors.

But check the fuel system first for leaks and make sure it has a good fuel filter.

Also check the lift pump, it should have around 7 psi.
 
I would do what Doc says,and maybe when you change the fuel filter,try putting a can of Seafoam in it instead of all diesel fuel,that will give the pump & injectors a good cleanout..if that fails to improve things,I'd do a compression test next--leaky valves can cause hard starts and incomplete combustion,and we all know diesels need at least 300 psi to run well and start easily...white smoke could be from coolant ,a bad head gasket is a possibility--pump timing can cause white smoke of its retarted too much and kill power to,along with making it start hard too...I think a sloppy timing chain has a lot more detrimental effect on a 6.2 than a gas motor..
 
When's the last time he changed the fuel filter? I would slap a new filter on it and see what happens.
 
when i looked at it. he had 2 new filters. the spin on up on the firewall and the little spin on at the back side of the intake.

talked some more to him today. late this past summer he had a batch of some bio or cooking oil in it. even since then its been going down hill.

he has now got it on regular fuel and the new filters.
 
hey diesel for me i thought these 6.2's had gears for timing and not chains? when i did the water pump there was gears in the no chain? unless its down farther or the cam only?
 
The injector pump is gear driven,but there is a timing chain between the crank & cam,unless someone swapped in an aftermarket gear drive instead..
 
well today got up to 50* so he played with it a bit. didnt have pressure gauge to test lift pump pressure.

starts on ether and have to give it full fuel pedel to barly keep runnin. skips bad and has some white smoke out the pipes.

does this sound like anything specific ? thanks guys.
 
Sounds like a blown head gasket, but a compression test will help to narrow things down. You can get a diesel compression test set at harbor freight for a decent price.
 
I'm with Kennyw Sounds like a head gasket or cracked head
 
If you end up needing new heads let me know, I have two sets of heads here, off of humvee's. I can't garuntee they will be perfect, etc, but they ran fine when pulled. Would damn near give em to ya if you needed some.
 
us74k5 said:
If you end up needing new heads let me know, I have two sets of heads here, off of humvee's. I can't garuntee they will be perfect, etc, but they ran fine when pulled. Would damn near give em to ya if you needed some.
Click to expand...
You wanna sell them?
PM me if so.
I have the 599 block, but no heads.
 
seems to me that the elephant in the room is that he ran used cooking oil, and now is having problems. Yes older IDI engines are the most friendly to running the stuff, but you cant get around the fact that they were not DESIGNED to run the stuff. IMHO to run SVO or WVO you need a very very complex filtering and cleaning and drying system to prep the fuel, and then more filters, and a tank heater on board the truck.

Sounds to me like a combination of possible coking of the injectors, clogged fuel lines, and waxing of the fuel in the filters.

Also of note, i know the first few tanks of biodiesel you run, it acts like a solvent, and starts breaking up the varnishes and deposites left by dino diesel, these deposites that are broken loose from the tank, work their way up the fuel lines to the filters and so on. this filter clogging shortly after using bio diesel has given bio a bad name, even though its related to dino diesel use.

If the filters have not been changed since he ran the WVO, he needs to replace the filters. I would also strongly advise a diesel purge (see sticky at the top of the GM Diesel forum, i posted it up with photos and step by step instructions) using either lubro moly diesel purge, or PS diesel kleen. and then put a full 32oz bottle of PS diesel kleen in the tank with fresh dinodiesel or reputable biodiesel.

might also not be a bad idea to pull the injectors and have them cleaned/rebuilt if necessary.

regarding a blown head gasket, and burning coolant, its easy to perform a pressure test of the cooling system to check for leaks. totally worth the time invested.
 
oh, another easy thing to check are the glow plugs. especially if he's having issues with starting the darn thing. white smoke can also be unburned fuel from a diesel. i get a medium sized white puff of smoke out the back of my truck when i start it cold after its been sitting for a while. i also have a coolant leak somewhere.... so maybe i have a blown head gasket, but mine drives like a champ, so im thinking its a leaking radiator.

BUT i digress. check the wiring for the glow plugs, and the resistance on the glow plugs themselves.
 
i know he used canola oil fuel as he grew it and had it made. not waste oil stuff.

and he has had bad glow plugs for a bit now. i dont think thay even work.

fixin all the fuel system will be a waste to time if that. truck not worth that much money in the end.

and when we did have it runnin foot to the floor it was for almost 1 min. so if it was cold start with out glow plugs i would think it would of cleared up by then.
 
If the glow plugs don't work, you may never get the cold cylinders to fire if the compression is low. I would always start with something cheap like GP's when you know they are not working.
 
see thats why i asked here. i dont know much on them other than super basic info.

i learned sumtin 2 day thanks :thumb:
 
well i guess his mechanic found a bad injection pump and also injectors. the lines are crusty with rust on the outsides.

so he wants me to look for some good used stuff .. . . . :whistle:
 
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