Help - 2.4 diesel DW engine won't run after IP shaft seal replacement

[blix99]

Thank you both for your replies and advice.

OK. I'll get a gauge and set the timing properly.

I did intend to borrow / buy a gauge, because I'd like to get it spot on, but thought that setting the marks up might be enough to tell me if timing was the main problem.
I'm not sure how critical even half a mm could be or if the margins are wider than this and it's something else?

What I mean is, if timing is out by an imperceptible fraction, could this be the issue?

What I might try, just as a quick test, is to advance and then retard the IP timing slightly to see it the symptoms change.

[ngoma]

Originally Posted by blix99

...but thought that setting the marks up might be enough to tell me if timing was the main problem.

Sometimes can get one running but lining up the notches to the marks is just a gross approximation. ALSO, you can have all the notches lined up at TDC, but the wrong TDC (crankshaft rotates twice to each IP rotation). Could you have inadvertently rotated the crank once while the IP was disconnected?

Originally Posted by blix99

I'm not sure how critical even half a mm could be or if the margins are wider than this and it's something else?

If you are describing mm viewing at the notches, yes, half a mm visible change there equates to a larger change at the gauge, but yet, seems like it should be close enough to start, if all else is viable.

Originally Posted by blix99

I've checked that each injector has fuel by cracking open each injector line on top and all seems OK. Cutoff solenoid seems fine (and pretty new). I've replaced all of the return pipes on the injectors. All this was done before the shaft seal change and it ran OK but with excess air drawing in.

So after replacing the seal, you didn't test for fuel (no foam or bubbles) spurting out the end of the injector hardlines?

Originally Posted by blix99

What I mean is, if timing is out by an imperceptible fraction, could this be the issue?

It can be, for some.

Originally Posted by blix99

What I might try, just as a quick test, is to advance and then retard the IP timing slightly to see it the symptoms change.

Probably worth a shot. Are the GPs functioning? Be careful about straining the injector hardlines if you are going to be rotating the IP. The preferred method is to rotate the camshaft rear cam on the camshaft, but this is only recommended if you have the gauge setup and a cam sprocket counterhold tool.

[blix99]

Thanks so much for taking the time and such a comprehensive reply.

I didn't move anything when taking the IP pulley off, so am pretty confident that it's TDC on No1, as this is where it all was when running OK, with the air leaks

Sorry, I typed in haste originally. I did check for fuel at the injectors after I had done this. I also primed to low pressure side of the pump too.

Based on what you say, I'm inclined to think the IP timing is the issue. I assumed lining the marks up was adequate to get it running but it seems it's a much, much smaller margin that this.

This makes sense when I think about it since the flywheel is maybe 400mm + across (at a guess) whereas the IP pulley is maybe 90mm. The degs and mins of these circumferences, in mm or fractions of, is massively different.

Anyway, I couldn't find anyone I knew who had a timing gauge, so I've ordered one. Should be here in the next couple of days.

I'll let you know how i get on but hopefully (hopefully : ) this sorts it.

Thanks again very much. I appreciate your time

[blix99]

Whoo bloody hoo : )

https://drive.google.com/open?id=1Nr...yVnGEH0rpgWPXX

Bought a timing gauge, just a cheap one. The brass rod that came with it; to place inside the end of the Injection pump and then inside the gauge body was too long for the VE pump so I used a drill bit. Necessity is the mother of invention and all that : )

Anyway, took me a while to get it to the right setting: 80 on the gauge (100th of mm? or whatever)

I adjusted this by moving the end cam cog rather than trying to rotate the IP itself. I'd tried turning the pump before which was almost impossible and certainly wouldn't have allowed any accuracy.

So, this has placed the marks on the IP cog past the mark on the bracket, which turning the pump wouldn't have done but I know this is the case and am happy with it. I might fix this at some point if i have to doo any other work around here but the main thing, nothing was broken and it starts / runs pretty well now.

What I will say to anyone who might stumble across this thread. Static timing of the Injection pump without a gauge is more or less impossible.
Turning the flywheel through the access slot under the IP, even just a fraction of mm had a huge effect on the reading of the gauge, which had a tolerance of + or - 0.02mm, which is pretty small by anyone's calculations.

I had to adjust several times to get the setting right. It looked OK a few times but when i rotated the engine and came back to TDC, it wasn't quite correct, probably due to tension in the IP. Once it was right, I rotated the crank by hand a couple of times with the gauge still in to check that it came back to 0.80 at TDC.

The only way you'd reach a proper setting without a gauge, as far as i can see, if via pure chance.

By the way, I referred to the IP timing sticky here, which was really helpful:
https://www.d24t.com/showthread.php?t=1684

Thanks so much for all your help. I really appreciate your time in replying and advice.

[Goteborg Vapenfabrik]

Improvising a drill bit is quite clever. Your engine is running very well now! Just be sure the fuel pipes aren't under unnecessary stress from attempting to rotate the IP to set the timing. Cracking the unions on the top of the injectors will relieve stress on the pipes. Congratulations on such a nice van.

[v8volvo]

Cheers! Sounds like a very healthy engine now.

Originally Posted by blix99

What I will say to anyone who might stumble across this thread. Static timing of the Injection pump without a gauge is more or less impossible.
Turning the flywheel through the access slot under the IP, even just a fraction of mm had a huge effect on the reading of the gauge, which had a tolerance of + or - 0.02mm, which is pretty small by anyone's calculations.

I had to adjust several times to get the setting right. It looked OK a few times but when i rotated the engine and came back to TDC, it wasn't quite correct, probably due to tension in the IP. Once it was right, I rotated the crank by hand a couple of times with the gauge still in to check that it came back to 0.80 at TDC.

The only way you'd reach a proper setting without a gauge, as far as i can see, if via pure chance.

Those are very good points, thanks for emphasizing them. Your last reflection in particular is one that is helpful for folks to see, and IMO completely true.

Unfortunately it does occur every now and then that someone happens to land on a functional timing setting by pure chance, without using precision tools or methods -- except they don't realize that they succeeded only due to blind luck, and instead convince themselves they have cleverly found a shortcut around doing the job correctly. Then they preach their "clever" method to everyone who will listen, and cause anyone who hears it confusion and trouble!

We had a case of this here on the forum just earlier this week, in another thread, with a member describing an encounter with someone who advised them that there is no need whatsoever for special tools to set timing. Fortunately that member asked first whether that was valid advice, rather than just taking it and suffering the consequences, as many do.

Anyway, successful outcomes like this one are very helpful in letting folks who are in doubt see the benefit of having the full information provided by the proper methods and equipment. Thanks for reporting the experience.

Would be fun to see more info and photos of your van, we never had those here so it's always interesting to see one of these engines in a different installation.

[blix99]

Hello again.

Sorry for the delay in replying. I'm still trying to get my van engine to work properly. I have a new question but will post that separately.

Here are a couple of photos of what my van is like and where the engine is located.

As mentioned earlier, it's a 1983 VW LT28D. The 28 signifies the gross weight of the unladen vehicle. The D is 'diesel'

This van would have been taken direct from the VW factory to Karmann, who produced many different camper conversions on behalf of Volkswagen.

Anyway. The engine is located in the cab, between the seats - actually in this case underneath the passenger bench seat. The bench seat folds up and out of the door to enable work on the engine from inside; predominantly accessed from above.
There is a solid, removable cover which clamps down over the engine when not being worked on.

I've not had this cover on very much over the last two months

Here are a few photos (sorry the first is sideways):