94 6.5L Blazer, what's it worth?

[a5150nut]

Before you trash the old starter take it to a rebuilder or do it yourself. Put it on the shelf. Every Lifetime starter or alternator Ive ever had failed. When you get tired of replacing them drag out your old starter and put it in.

[scottm]

I had the glow plugs out and spun it last weekend. Today I opened the filter housing valve and ran the pump. And I opened the bowl drain valve and ran it a couple times, made a big puddle on the ground. Is there a purge valve to open on the injection pump?


The glow plugs are working. I plugged in the block heater and warmed it up. I unscrewed 6 of the 8 injector lines, as I couldn't get to the ones under the turbo. I cranked it and had fuel flowing at each one. Hit the key and it ran for 3 seconds! But then it died and wouldn't start again. Cranking just leads to the occasional cylinder firing but no starting, same as yesterday.


Running out of ideas here. Could the fuel be bad? It still smells like diesel. Maybe I need to check compression?

[DmaxMaverick]

The fuel is good, if it doesn't smell like something else. #2 can be contaminated, but does't spoil, like gasoline. I've used 50+ year old fuel that sat in tractors in fields with no issues. As long as it's clean, it's good. Actually, any fuel you find that's been around a few decades is probably much better than the crap they're pumping these days. I wouldn't use it in the later models with all the smog crap, but I'd burn it through any of mine.

It's still airlocked. Loosening the injector line nuts only pushes fuel, and won't pop the injectors. Sometimes it works, but not often in the extreme. Take the above advice. Remove the glow plugs you can, and spin the engine until you get fuel mist from most or all of the holes. The IP is self-purging, and has no manual method. An airlock condition is the cushion of air in the lines, which prevents high pressure from popping the injectors. You can wear out a starter and some batteries just cranking away with no resistance. It will eventually work, but you may cause more damage than help. The volume of fuel at each injection event is very small. High pressure makes the air bubbles small enough to just pass through the system.

[scottm]

I want to check compression before putting much more into it. Does anyone make a fitting that goes in the glow plug hole? And what will happen if I squirt a little motor oil in the gp holes to lube up the rings? Will it run on that oil?

[Yukon6.2]

To do a compression test you need to remove all glowplus
And you need a diesel specific compression tester which probably will have the proper fitting.
Personally i would get it running first seeing it sat so long.
To really get an idea on the health of the engine it should be a running engine.
Bring it up to operating temp, test the cylinders dry then add the oil and retest.
With the glow plugs out it will not run, with them in it`s a good chance it could run on the oil as that is what a diesel is designed to run on.

[DmaxMaverick]

Harbor Freight has a Diesel compression test kit for not much $$. It should have the GP hole adapter. Check the description for compatible engines. I think they had more than one option, last I looked.

To be accurate and consistent, a compression test must be done on a warm/hot engine, with all the GP's removed. Charge the batteries to full, if running didn't do it. Disconnect the ESS (Engine Stop Solenoid) on top of the IP during the test (stops fuel flow). Crank exactly 6 puffs (compression cycles) and record the value. DO NOT "wet" test a Diesel engine. When you put it back together and start it, it will burn off all the oil very quickly, and can cause overspeed. There is no requirement or published specified result of a wet test.

[scottm]

I ordered a diesel compression tester kit from ebay, should be here soon. I just got this book from the fine folks at the diesel page. Looks great and I'm going to read every word:

The 6.2L/6.5L Diesel Troubleshooting & Repair Guide