Hi H1 friends. As you might remember from my last posts, I have a 2000 4dr soft top that I ran for a while on SVO. It didn't work out so well. I blew up a few IP's. That's not a fun job, replacing it. But over a year ago, the truck just died again. Ran crappy (sputtered, staled, restarted etc). But it finally just quit. I tried three different PMD's, to no avail. Changed to a stock PMD harness (I had extended mine and relocated tothe battery tray). No luck. I thought I might have burned a valve or piston due to high EGT's after installing Predator's "stage 1 wake up kit". I planned on tearing down the heads and seeing if the valves were shot. I started taking the upper end apart. Then I got sidetracked. I had another vehicle to drive. My ADD took over and I left it for a long time. Recently, I bit the bullet and had it towed to a local Diesel shop (Shimandle's in Norrth Royalton, OH). I'm naming them, because they did a great job and treated me right. Brad, who worked on the truck called me and told me he got it running and there didn't seem to be anything wrong. BTW they used my PMD and extended harness with no issues.

My original post
https://www.hummerforums.com/forum/h...ght-pmd-24805/


HERE'S WHERE MY QUESTIONS START

1. When it first died, I tried everything my limited knowledge base allowed me. I cranked it over for several minutes (not in a row.. I gave the starter some rest between tries). I tried to check compression with a Harbor Freight Diesel comp tester. I had good compression in 7 cyls but one (i can't remember if it was driver or pass side) back of the engine only read 100#. The others were all over 315#. I also thought that I had stripped a glow plug hole. I was using very light pressure turning the comp test plug into the hole when it broke free and started to spin easily, then snug, then easy again.
The guy who got it running says all glow plugs went in fine and none seemed stripped ????? Maybe just the first couple threads stripped, and the plug compensated for this? Why was one cylinder (NOT the one with the "stripped" glow plug threads) low? (this is what made me think I had a bad valve or piston)

2. Like I said I cranked it alot. I thought that Hummech (Mike had told me these fuel systems would "self bleed" with continued cranking. I honestly can't remember if I had cracked an injector and tried it the old fashioned way. But do you think I could have just had air that wouldn't clear, and a good bleeding was all that was needed? The guy who got it running just "put things back together (plug harnesses fuel lines etc." and bled the fuel lines, and "whammo" it started up. It seems to be running fine now...

3. Another (unrelated) issue I had just noticed prior to the break down was that I seemed to have a rapidly worsening trans fluid leak right at the front seal area of the trans (there was almost a steady stream leaking out of the hole at the front bottom cover). The shop found it to be 4 quarts low. BUT THEY COULDN'T FIND ANY LEAKS????? I drove it home last night. No leaks... Brought it to work today,,,, no leaks? What could have leaked that bad before, and remedied itself by sitting for over a year??

This is just ODD.

 

If trucks sit a lot the hoses can get dried out and crack and leal when you start using again. The more you use it the leaks may get better or even disappear for awhile but the hoses should be replaced.
2000 year model could be the number 8 cylinder issue on your low pressure reading. The split cylinder wall will cause a slow, at first, drop in coolant level.
People that ran SVO seemed to go through a lot of injection pumps. One thing people forgot is that the filters got plugged up fairly quickly also.
You can bleed the fuel system at the valve inside the drivers front wheel well or loosen the fitting on top of the fuel filter canister and turn the key on until you get a solid stream of fuel.