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1983 blazer diesel help.

Kurlymo0015

Kurlymo0015

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Just bought a 1983 Blazer 6.2 diesel with banks turbo automatic 4 speed. I ran out of gas unknowingly because the seller failed to tell me the gauge is broken. Now it is running rough, stalling out, no power in 2nd gear and up and erratically speeding up and slowing down. It is basically undrivable. Also is dying while in neutral. Don't really know what is going on. Any help would be appreciated. Did I clog the fuel system with gunk from the bottom of the tank? Another problem I'm having is fueling it up. The diesel just bubbles up and out if I try and fill it up past 6 gallons. I figure the air isn't escaping properly but I don't know where the clog is.
 
It's quite possible you did suck up water and gunk from the tank's bottom running it out of fuel...also air will get in the fuel lines and cause it to run weird ,possibly stall,but that should clear out after you got it re-started,which is not always easy once you airlock the injector pump..

That is IF you really did "run it out" of fuel..perhaps it was still over half full ,and it only took 6 gallons to fill it up ?..and its running poorly due to another cause,maybe a clogged fuel filter or sock filter in the tank,etc..perhaps the fuel lift pump on the engine took a dump or is gunked up ?..

The tank has a 1/2" vent hose connected to the fuel filler neck that should let air out as the tank is being filled..maybe some dirt daubers built a nest in there or something..the gas cap should be vented,air needs to get in the tank so fuel can flow out thru the fuel lines..if its blocked it'll possibly make it stall after several minutes..(pretty rare though)..
 
While I'm filling the tank fuel comes up out of that vent hose. I assumed it was for venting but nothing but fuel constantly burps out of it while I'm filling.
 
A lot of the diesel pumps around here seem to be geared towards 18 wheelers,they deliver about 50 GPM,which tends to overwhelm our dinky
1-3/4" or so filler necks..it comes out like a fire hose!..
I have to use a feather touch on the trigger when I fill my truck's tank--or risk getting a bath of stinking diesel !..especially if its not real empty..perhaps thats the real "problem",not so much your truck's tank..
 
The 6.2 is a governed engine. The erratic engine speed changes are consistent with what happens when you have trouble getting fuel into the IP. The governor opens up the IP when it runs out of fuel and the engine surges when fuel does arrive. The governor over reacts and a periodic pulsing happens until a steady supply of fuel is available.

This can be caused by swollowing an air bubble or by ingesting bad fuel (non-burn able). Either one should resolve after good fuel reaches the IP.

If the tank seems full, I would vote for fuel not reaching the engine. My K10 did this due to a leak in the fuel line (on the suction side of the pump). So it was constantly sucking air and fuel together. Surging, stalling, and rough running resulted.
 
Kurlymo0015 said:
While I'm filling the tank fuel comes up out of that vent hose. I assumed it was for venting but nothing but fuel constantly burps out of it while I'm filling.
Click to expand...

This is how full fuel tanks act. Ask me how I know...

Do you have some way of verifying that the tank isn't full?
 
I know it's not full. I can only put in 6 gallons. Than the neck fills up and stops draining. If I rock the car drive it around or force air out of the tank with a air pump it will drain and I can fill it more. It would take me hours to fill a 31 gallon tank. I got 6 gallons in this way it took me 1.5 hours. I am afraid to drive it as I don't want it to run out again and cause the issues I had previously. Btw I fixed the issue by purging the fuel lines thank you all for that help on that. Now I need to figure out how to fill the tank up. While filling. fuel poors out of the air line that is parallel to the fill neck so I'm thinking that the "air" inlet line is dipped too low in the tank and covered by fuel. So when I fill it the air pressure that is attempting to escape pushes fuel up that line. When the weight of the fuel isn't enough to counteract the air pressure that isn't being released the full stops filling and sits in the neck. The guy who owned it put 8 inches of body lift on it so I'm thinking he added a line to extend the neck and put to much of the line into the tank. Any help would be appreciated. I don't want to have to drop the tank if I don't have to.
 
With 8" body lift you should be able to work on the tank without dropping it. I would suggest removing the unsafe lift and returning the fuel filler hose to stock. It will work better that way.
 
Yes. It's very unsafe lifted in multiple locations with multiple pieces in the same places. Can't wait to take it out. I cAn reach the tank where it is right now but I'm not sure what all to do. I'm waiting for the mechanics manual at the moment.
 
Kurlymo0015 said:
Yes. It's very unsafe lifted in multiple locations with multiple pieces in the same places. Can't wait to take it out. I cAn reach the tank where it is right now but I'm not sure what all to do. I'm waiting for the mechanics manual at the moment.
Click to expand...

If it's easily accessible, pull the filler neck off at the tank and see if either hose is plugged. You should also be able to finish filling up the tank without the hose, if it's sufficiently accessible (just guessing at this, as I don't have any pictures of your setup, but it is what I did on my pickup when the bed was off).

But it sounds like you still have a problem on the engine side. Surging at idle means you're not getting steady fuel delivery.

Maybe you sucked up some crud and plugged your fuel filter. Worth checking, at the least. :dunno:
 
You guys were all right and now I feel dumb. The tank has been full the entire time. This begs the question why/how did air get into the system? Some back story on the subject: I drove 180 miles to buy the blazer on a Sunday. Bought it thinking everything was good to go. Broke down about 30 miles away from where I bought it. After a night at a hotel I limped to a diesel mechanic. Turns out the EPR valve was stuck shut. The mechanic temporarily fixed it. So I made it as far as 60 miles from home. The valve got stuck again. I limped off of the freeway constantly stalling and not being able to go above 20 mph. I parked it and came back two days later. Removed the valve completely, the mechanic had just used wire to hold it open so it didn't last very long. I drove another 45 miles and the blazer started losing power and stalling. Different problems than before. After getting help from all of you I cleared the air in the fuel system and now she's running great. Could the blocked exhaust system have forced air into the fuel system? Or is it more likely that I have a leak in the fuel system where air is getting in. Like said after the fuel system purge it's running fine and I don't see any air bubbles in the clear pre filter. I also changed the fuel filter when I did the purge. I would like to start driving it to work but I'm afraid I might break down. So for now I am just driving it close to home to see if I have any more issues. Thanks reading. Any help would be appreciated.
 
Kurlymo0015 said:
You guys were all right and now I feel dumb. The tank has been full the entire time.
Click to expand...

Don't feel dumb. I suggested checking the tank because I have done the same thing. :doah:



Kurlymo0015 said:
This begs the question why/how did air get into the system?

...

After getting help from all of you I cleared the air in the fuel system and now she's running great. Could the blocked exhaust system have forced air into the fuel system? Or is it more likely that I have a leak in the fuel system where air is getting in. Like said after the fuel system purge it's running fine and I don't see any air bubbles in the clear pre filter. I also changed the fuel filter when I did the purge. I would like to start driving it to work but I'm afraid I might break down. So for now I am just driving it close to home to see if I have any more issues. Thanks reading. Any help would be appreciated.
Click to expand...

I would not think that the exhaust issue could have caused this. And the EPR is not a requirement for running this engine (2 of my mine came without them). More on this later if you decide that it's in your way.

As for air getting into the system, I would bet that you have a leaky line somewhere. When my truck did this I plumbed up an electric fuel pump just downstream of the fuel tank. Pressurizing the fuel line made it more obvious where the leak was. And it also provided an easy way to purge air from the lines before startup. If the air gets purged from the supply line before it gets pumped into the IP, the stalling problem is eliminated. So I would run the pump for 10-15 seconds before cranking the engine over. After that, the fuel line didn't bother me until the leak got bad enough to start dripping fuel. And then I knew where the leak was. :rolleyes:

Not necessarily the best solution, but it gave me a cool switch on the dash. :)
 
The EPR valve is operated by a vacuum canister ,which has a spring inside it,that holds the "butterfly" in the exhaust pipe in the open position and it'll only close when vacuum is applied to it..

I imagine it would be rather rare for one to stick in the closed position,but I guess anything is possible..

The one on my '82 pickup is not hooked up any more (and even if it was,the vacuum pump was dead anyway,so it wouldn't have worked)..driving it with it open all the time has not displayed any adverse affects to the driveability..
My EGR valve is also inoperative,but is still bolted to the intake..

I have a J code intake on a parts engine,but so far havent had enough ambition to swap it on..doubt it'll make much of a difference,really..not for the uses I use the truck for anyway..
 
I'm going to take out the ridiculous 8" body lift on my newly acquired 83 diesel blazer. Any advice/help would be appreciated. What all do I need? Should I leave in any body lift at all? Or just bring it to stock? It has 35's on it right now. Once they wear down I want to put 33's on.
 
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