I put a compression test on my 7.3 .Every cylinder got to only 100 psi.It seems odd that there wasn't a few cylinders that went higher or at least some difference in readings.This is the second powerstroke to do this.i pulled the first engine out for low compression and put this engine in its place.Could I be washing the cylinders out trying to get them to start? I know people are going to say rings but can there be any other plausible reason for such low consistent readings? Can the truck even fire on 100 psi?

 

That means your compression tester might be bad. Odd enough that all cylinders didn't go past 100 psi.

 

double that.

sounds like the needle gets stuck at 100PSI for some reason and won't go past it.

Hook up shop air to it and see if it'll go past 100.

 

I put oil in one of the cylinders and got 200 psi

 

I've had some engines that have sat for a while, been cranked over and not starting for a while register next to nothing on compression. I had a gas engine that showed 20psi, 80, 30, 120 etc I thought for sure it was a dead engine. Was a running pulled jy motor with only 60k that just sat a few months. Once I fired it up and let it get up to temp, maybe the rings sealed better or something it was like 160 within 5psi across all 8. Maybe you're seeing something similar? I'd try a new tester too.

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Has this engine run recently? Or had it sat for any time? I just picked up a dead Kubota tractor I bought this weekend, it looked "great" inside, I still got compression (by hand) and smoke while cranking it, it even sputtered for 30 seconds on its own before I pulled the head. I noticed the heavily pitted cylinder sucking back through the exhaust so I knew the exhaust valve wasn't sealing right.

 

I went a bought a second diesel compression tester and again I only registered 100 psi.I added oil to a couple of the cylinders and they came up to 200 psi.This motor sat in a junk truck for several years and haven't run yet.I am hoping I can add oil to the cylinders and re lube the cylinders and hopefully start the engine

 

OK so you have never had this engine running? In this case, it is the ONLY time I would recommend starting fluid. Disconnect the glow plug relay and spray it in short bursts while someone cranks. I actually use Electronic Parts cleaner, it's not starting fluid, becuase I refuse to use starting I don't stock it, but it works just like it. I bet from all of the condensation there is light pitting on the cylinder walls preventing it from getting good compression. Once it heats up and runs a few minutes the rings will seal 100 times better. It's also possible the condensation may have created a small amount of rust on the valve seats from sitting. Engines that sit can loose all go the oil film that protect them from rusting, or so I have seen. Condensation gets in everywhere. The air warms up 20 degrees outside but the large thermal mass of the block doesn't so moisture will condense on it and inside of it. I can't remember in your other thread but a block heater would also do wonders in helping you start

 

I should clarify we had it fire momentarily on ether but it has never run and it has only fired momentarily 2 or three times in the year it's been in the truck

 

Are you able to keep it running by carefully spraying bursts of ether? Does it smoke at all while cranking? With the oil cap off is their smoke coming out or air that you can hear?

 

Cannot keep it running on ether as a matter of fact can't get it to fire on ether.no smoke coming from tailpipe either and I have 20psi fuel pressure when cranking

 

Fuel pressure won't matter for ether. It's strange you can't get it to fire on any cylinder either. Ether would eliminate the fuel injeciton system entirely as a culprit it usually helps determine the valves and piston/ring health. Have you checked the turbo for a blockage from a mouse? Have you tried spraying the ether after the turbo, directly into the head intake?

 

If it won't fire on starting fluid then that engine is toast

 

Even with 200 psi it will be hard to to stay running. If it looks anything like the pictures posted forget it.

Your obviously not getting fuel to the cylinder, so you can crank and spray all day without it maintaining a turnover.

Unfortunately I'd agree that motor is not worth the time of trouble shooting.

 

If you haven't remove the intake Y after the turbo I would still check there incase something made a nest that got sucked into the turbo. Starting fluid will make things fire missing half their cylinders. I can't see water or other damage to all 8 cylinder beyond getting it to fire. It may not be getting air or starting fluid through it if you were spraying through the turbo. Can you smell the starting fluid leaving the exhaust? Putting your hand over the turbo while cranking does it pull good vacuum?