I'm probably going to have to wait until the morning for a compression test, but assuming it's good then what? I've got fuel, air and spark as far as I can tell and the bi*** still won't start. I'm thinking a match at this point.

 

Interesting side note; I can still smell starting fluid when I crank her over even though it's literally been 3 weeks since I sprayed any into the intake. Normal?

 

When you remove the spark plugs for the compression test, look at them right away as you take them out and see if they look wet with gas. If the spark plugs are wet with gas, you can be getting spark through the wires but they won't spark inside the engine. This would seem to be the scenario if you get no response from starting fluid.

 

I had pulled the plugs again yesterday to check them when I did the regulator. I wouldn't say that they were wet, not obviously anyways. Also on most of them they were starting to show signs of firing, starting to get tanned if you will. I blew them all off anyways and left them out while I changed the regulator. Same thing, no start, though when I put them back in afterwards and immediately tried to start her.

 

Well, you've got a strange one on your hands. I thought you would find wet plugs for sure after eliminating the timing. Compression test will still be interesting, but it's become a long shot.

There is a saying that you need three things to make an engine run. Fuel, compression and ignition. If it's not running, which one is missing? At this point, I'd say you have them covered. Not a mystery I can solve.

Good luck!

 

OK, update.
Did the compression check on all cylinders. Wow, low. Bear in mind this is engine cold, obviously since it won't start but the results are pretty telling. I did not do a wet test, this is just dry with WOT.
#1 - 95
#2 - 90
#3 - 90
#4 - 100
#5 - 90
#6 - 95
#7 - 105
#8 - 95

Now again I'm not a mechanic, and I can't find any "recommended" values for proper compression PSI; but from what I've read I should be seeing something at least in the 130'ish range across all cylinders. Please correct me if I'm wrong.

So seeing as though they are all within 15%-20% of each other, I don't/didn't "think"(dangerous word for me) that I'm looking at a really failing engine here. Again please correct me if I am wrong.

I went back and really checked the timing this time, bear with me as this is my first (well technically third I guess counting yesterday) time doing this. I cleaned everything off real well on the balancer again and made a very obvious, but thinner, yellow mark at the 10*. As far as I can tell I was wrong yesterday when I said it looked to be timed at the correct 10*. It now looks as though I'm more in the 6*-*8 range.

Do we think that this is my problem folks? I sure hope so.

 

Those compression readings are lower than expected. Depending on the CR, I would expect somewhere from 110 to 130 lbs. Normally, I would think the timing would be a good indicator of a slipped timing chain, but low compression could be as well. Perhaps PO reset the timing before you bought? (just a hunch).

Normal cylinder pressure would be atmospheric pressure X compression ratio. I think a 7.5l is 8.5:1 compression and with atmospheric at 14.7 lbs, that would be 8.5X14.7= 125 lbs. (approximate).

If you pop the valve cover and observe the intake/exhaust rockers on the #1 cylinder, you should be at top dead center between the exhaust closing and the intake opening. Maybe see if this correlates to the timing marker on the damper? Out of sync would indicate a jumped timing chain.

 

Not Enough, while it's possible the previous owner did something with the timing I really can't say for sure. It does seem to be not quite advanced enough, but I don't know if it would be enough so that it didn't start.

Ok so update.

I checked the oil, because at this point I'm just grasping at straws, and it was really full, like really full to the point where I knew something was up as I would never have put that much in. And it smelled like gas, uhoh. That speaks to major flooding, to me anyways, even though my past spark plug inspections didn't reveal anything obviously abnormal to my untrained eye.
So I drain/change the oil, pull the plugs and crank it over to blow it out. Put it all back together and try to start with the FP relay pulled and WOT. The smallest, smallest split second she sounded like she wanted to catch, twice. But then nothing.
Pulled the plugs again and crank it over. Back in and try to start with FP relay pulled, not a sniff. Same with FP relay in.
Check the oil again and it still smells like gas. Change it again, pull the plugs and check compression again in a couple cylinders, 3&4 because they're easy access, and compression has improved +15 and +10 psi respectively. Crank it over some more to again blow it out. All back together, nothing.
What. The. F***
It looked like I was on the right track because of that sniff, and may still be, but I'm having trouble believing it's still flooded. I think I'm close though and trying to stay positive here. Anyone know anything that could possibly push this girl over the edge?

 

First you need to get the fuel pressure back down were it should be. You may have to replace the FPR or check for a pinched fuel return line.
Gas wash cylinders will give lower compression.

 

I changed the FPR yesterday? It's all blending together at this point but either way it's been swapped out. The old one definitely had something rattling around in it when I got it out and shook it. So that part's done. I have not as of yet checked for a pinched return line though. Pressure at the rail was 34'ish with KOEO with the new FPR installed, whereas before it was 0 and wouldn't move till I cranked. In conjunction with the pinched fuel line search I will also check fuel pressure on cranking.

 

You need to check the pressure with pin #6 of the Self-test plug grounded or shorted to pin #2 with the key on. It should be 40psi.

Do not worry about fuel pressure while cranking or turning the key on and off as the pressure could be any where. If you turn the key on and off enough you should also get around 40psi. However it should never go above 40psi unless you have a blower on the engine.




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Subford, thank you for the pictures.
Just went out and did the test. It's dead on at 40 PSI.

 

90 PSI of compression is extremely low. I'd expect 130-140 PSI at the minimum for a healthy engine. I think it'd still run with 90 though.

 

At this point I think I have so much gas wash, and possibly so much gas period, that that has shot my compression. Again at this point I'm going to keep pulling the plugs and adding oil/cranking until when I put her back together again she fires I think.

 

Note a few drops of oil into each plug hole will bring the compression back up for a gas washed engine.