dead cylinder after rebuild

[rabbitman]

That spray looks fine to me.

[Mark(The Miser)UK]

Does this spray pattern look normal? this is from the pump outlet for my #2 cylinder? I ran 3 differnet injectors and they all looked the same. http://www.youtube.com/watch?v=z0gOuSEbpyI

I also found a better comp tester. I get 350 psi-(leaving the other 3 injectors in. It would be higher with them out.) Plenty enough that the cylinder should fire. Out of desperation, I even tried a different fuel line.

Compression sounds  fine.
The injection seems ok. Especially as the other injectors give same pattern.
It would have been easier to tell if the camera was back a little more, and the target was perpendicular  to the spray perhaps 1ft to 18" away.
A further test  for comparison would be to do the same  trick with one of the other fuel lines, just in case the problem is in the delivery valve.
Good luck.[three hours between writing and posting!]

[sdwarf36]

Tested a few more things. I did a leakdown-7% leakage-all past the rings. not suprising considering this cylinder has never fired to put a load on the rings. Also tested compression on a running cylinder-close to 500.  A little more difference than I thought-but its a seated ring vs a washed out one.

[rabbitman]

350 psi is plenty enough to get it to fire.

With 350psi, a good injector and injector line and still a dead cylinder I think it's time to look elsewere, the delivery valve would've been rechecked by Giles so that shouldn't be an issue.

You didn't leave the exhaust lifter out of that cylinder..........

[sdwarf36]

No-i remembered all the valves + buckets. Lash is on the money too.

[maxfax]

Did you forget and leave your "stash" in the #2 intake runner? 

[sdwarf36]

Something in the intake port crossed my mind too-but without air you wouldnt get compression.

[rabbitman]

Something in the intake port crossed my mind too-but without air you wouldnt get compression.

That's why I thought exhaust side. This is weird.

It sounds like you have timing way off on one cylinder, not possible.

Did you try taking all of the injector lines off and cranking it so you can see the order of injection? Not like that can change either but I'm about out of ideas.......

[maxfax]

Well, yes and no..  Thinking out loud here - It was pretty common back in the final days of GM using flat tappet cams that the lobes would wear off rather quickly.. Typically you'd have a very weak or dead hole with a low compression reading.. Although in your situation you still seem to have about 70% compression which is much better than the 40 some percent that would usually be found on those.. And enough that it should at least fire somewhat..   Plus I would think that whatever is stuck in there would have gotten sucked though the engine by this time..   For spits and giggles your could try the leak down tester on the intake and exhaust strokes to see what may happen..


Had you tried another #2 injector line??  I missed you mentioning it if you did...

I'm on the same page as rabbitman at this point..  I don't see how a pre-cup could really be screwed up as they usually just fall out or explode.. But who knows..  I've run into the exact same situation you are having on the old Case power-cell diesels.. The power cell (basically a pre combustion chamber) burns out so to speak.... The cylinder will have good compression and fuel but no fire till you replace the power cell..

[rabbitman]

For spits and giggles your could try the leak down tester on the intake and exhaust strokes to see what may happen..

You mean to check if there's "open valve flow" or "open valve with something else stuck in the port flow" right?

[maxfax]

For spits and giggles your could try the leak down tester on the intake and exhaust strokes to see what may happen..

You mean to check if there's "open valve flow" or "open valve with something else stuck in the port flow" right?

You got it..  At this point I guess it can't hurt.. If nothing else maybe it'll lead him to something totally unrelated that is causing the problem.. It's happened to me more than a few times while chasing odd ball issues like this..

[81 vw pu]

A friend of mine did a rebuild on a 89 ford ranger 2.3 years ago and after a full rebuild had a dead cylinder with good compression/fuel and fire.
About drove him nuts trying to figure out what was going on. Ended up being a plugged exhaust port in the exhaust manifold on a runner with a sharp turn.
It was oil carbon from broken rings on that cylinder that was ran for who knows how many miles. No. 2 exhaust port on the vw td is fairly short but can be checked with a leakdown test with the exhaust valve open.

[nathan_b]

Something in the intake port crossed my mind too-but without air you wouldnt get compression.

I know for a fact that a 1.8t engine will make 120psi compression with no cam even in it. so while you do need air, not as much as you would think..

[Squidbait]

Sorry if this is a dumb comment, I'm still a total noob as far a diesel is concened.... but I don't see a mention of glow plugs.  Can you get combustion from cold on compression alone?

[92EcoDiesel Jetta]

You have enough compression, leakdown test not bad, you are getting fuel (at least #2 inj is spraying into open air). Maybe somehow fuel is not getting into #2 cylinder? I'd, in addition to looking for blockages in the exhaust already suggested, check for blockages in the swirl chamber. Take the injector out and blow air into #2 hole and verify there's no clog. Do it with valves open and closed and listen at the appropriate ports.