Help resurrecting dormant military 6.2 blazer

[dka99burb]

My brother-n-law has an old military 6.2 blazer that has been sitting for a few years. He was talking of the gas swap and I stopped him. What should we do to try to start the old girl? I have been learning a lot about these GM diesels with my burb but it has not sit and is not straight mechanical. I figure we start by changing fluids; including the fuel. Where from there? Clean IP? disconnect lines? what's next? I guess I am worried that if there are contaminants in fuel they mess up the IP or clog injectors.. Suggestions appreciated.

 

[ak diesel driver]

install an electric LP and then pump new fuel all the way to the IP. run it into a container so you can see what it looks like.

 

[BigBlueChevy]

Change the oil + filter and reprime the engine too. Fill the engine with about 5 quarts of oil, and put the other 2.5 quarts into one of those "bug Sprayers" (the ones you find in the lawn and garden aisle to fill with pesticides, then have to pump up). Replace the hose with one that you can run into the main oil rifle of the engine and pump that last 2.5 quarts of oil in that way. It will pressurize the engine with oil BEFORE having to spin it over. Other than that there's not much to it. And no matter how tempting it is, DON'T use ether to try and get it to start. Even with the glow plugs disconnected.

Good luck!

 

[WarWagon]

Pump some fuel out of the tank from the fuel filter and see what it looks like. Getting old fuel out of the IP will be the hard part.
Otherwise if the fuel smells good and is clear you can use it.
I would change the fuel pump as suggested as well as the fuel filter.
You need two good batts and 100 RPM min to start. Used junk batts will not do the job.

Don't drop the trans oil yet unless you want to refill the converter - A long process taking like 9 quarts. The converters will drain into the pan over several months. Or it did with the 4L80E I had sitting and dropped the pan before starting the engine. Be warned it will take 30 min to get the converter air bubbles out 1 quart at a time.

 

[dka99burb]

Thanks guys. I am looking forward to going down to visit and play with the 6.2. I don't know if he will beat me to it but I will send him the info.
Does the 6.2 not have an electric fuel pump? I assume it uses a mechanical one mounted where our turbo drain plate is located?

 

[just a number]

you assume correct about the pump location. the 6.2 used a mechanical pump. either way works. the electrics are a lot easier to prime/bleed, but can get expensive. you could clear out a lot of the old fuel in the IP by disconnecting the return line on the top of the IP and supply power to the shutoff. do it after you drain the bulk at the filter.

What setup are they running 24V or a converted to 12V?

 

[dka99burb]

I don't know yet. I have to get back with him. I told him that we had to play with the 6.2L before I would let him swap it to a gasser. I think he may stick with it if I can prove it to him.
He is in East Texas.

 

[3500GMC]

Always totally bypass the mech LP when/if you switch to an electric LP.

New batts, crank 'er up! Give the starter plenty of time to cool if fussy.

 

[WarWagon]

The fuel pump concern/suggestion is because the old fuel may have eaten the old diaphram in the mechanical fuel pump. It will cheerfully pump fuel into the crankcase if the diaphram goes bad. Electrics are less wear on the starter during filter changes. I would replace the fuel pump even if you are staying with a mechanical unit just to be safe.