1986 6.2 with no one around to give me advice

Hey guys! I have read threads from this site before and they have helped me a few times already, but i am having problems answering some questions about my truck lately. I dont have any friends familiar with diesels, and this is my first rodeo with one.
I have an 86 gmc with the 6.2. After some fuel gelling issues in cold weather that i was unaware of, i burnt up a starter one weekend trying to get her to start. New starter, fresh fuel and some winterizer cured that issue. Expensive mistake, but live and learn.
During the starter install i noticed i have a fuel leak under what looks like the passenger tank, but i havent been able to tell of its the transfer pump or a tank/line issue yet. (24 degrees and snow today in ohio)
The last time i drove the truck i noticed it would jump up a couple hundred rpm on a steady cruze without any throttle input, and on the same trip it also lost power a couple times. (Pumping the pedal and no response) i thought i was gonna have to call a buddy with a trailer to get me home.
I scared myself reading online cause i kept seeing “runaway diesels” while searching, so i have parked it and not driven it since.
I was able to find a post on here where the owner replaced fuel injectors and it seemed to clear up his idle surge problem, but i was hoping i could give a run down of whats happening and see if anyone could give me some advice- in case my issue is different then his-
So with the truck in the driveway i started it the other day, it started relatively easily after 2 glow plug cycles, but ran really rough and never quit smoking out of the passenger side. With a tail wind from the field i had smoke traveling easily 50 feet past the front of the truck.
The driver side seemed to not be smoking after start up, but passenger side just rolled smoke. During the 3-5 minutes i was trying to keep it running. It seemed to sort of chug for lack of better terms, like i had to hold the throttle and rev it to keep it running. After a few minutes with the smoke not clearing out i shut the truck off in fear that i might make things worse and once again started researching my new problem.

The internet is a great thing, but theres almost too much information on it. -as in, when you want to find one specific answer but no matter how long you look, you only find other things. Like 6.5 trucks, cold start videos, turbo videos, and cat videos. Haha

I hope this post isnt confusing, and im sure i probably have more then one issue with this truck, but if anyone on here wouldnt mind giving me some tips as to where to start, i would so greatly appreciate the favor, your time and help.

Have a great day! And thanks in advance to whoever might be able to give me a couple tips!
-Brian

Hi
It's pretty tough to get an old 6.2 to run away without messing with the injector pump.
No transfer pumps near your tanks,just a mechanical one on the engine unless someone has added one.
Your tank leaking is probably a rust hole,the tanks have a gravel guard that fills with mud ans salt over the years.
Your one bank smoking sounds like bad glow plugs,but could be injectors.I would check,change the glow-plugs first.
I would also start chasing your fuel system for leaks.Leaks in the fuel sytem could cause all your issues as well.I would switch to the tank that dosn't leak and start diagnosing the fuel lines for leaks,one way is to slightly pressurize the tank and watch where the lines get wet.Not much pressure maybe up to 5 lbs

Thanks! Being new to diesels its hard to even know how to word a question properly.
But i appreciate the advice! I will get a new set of glow plugs first and start chasing that fuel leak!
I appreciate your time!
I will jump back on here and let you know how it goes!:cool:

I had an issue similar to this on my International truck. Lots of white smoke, loss of power, knocking. It ends up I had one injector stuck open. Replaced bad injector, problem solved.

Always begin troubleshooting a diesel engine running problem by making sure the basics are covered...

1- Plenty of fresh clean diesel fuel in the tank (no gasoline, water, algae or old fuel)?
2- Clean fuel filter? Replace it even if it's only been a couple months in service. A partially restricted fuel filter can cause surging.
3- Lift pump generating fuel pressure? A bad lift pump can cause surging.
4- Air leaks in the fuel supply lines? The twin saddle tanks and switcher can produce an air leak. Some amount of air in the fuel supply lines can cause surging.
5- Wiring integrity?... begin by checking all of the wiring connecting to the fuel injection pump, work your way back to the fuses and ignition switch if necessary. A faulty cold advance solenoid/sensor/wiring could cause a 200-rpm surging problem. Normally... the HPCA (Housing Pressure Cold Advance) solenoid system within the fuel injection pump raises the engine idle speed by 200-rpm (combination of idle speed solenoid and timing advance) when the engine temperature is below about 95 degrees. So, a bad wiring or part can cause it to go up and go down by 200-rpm when it's not supposed to.

Jim