Author Topic: testing glow plugs (Read 7501 times)

Jettagli16v · « **Reply #30 on:** March 03, 2009, 11:30:46 pm »

OK, Now I have 4 new Duraterm's in and 90% pimped wiring.
It only took about a half hour to install the plugs (lines still on)
but that was largely magnet trickery, and gear wrenches.

I was unhappy with the fused distribution blocks available from the auto parts stores,
so I will find a nice one tomorrow,
and finish the "everything glow plug related is brand new" job.
At that point if the damn thing dont run, I am down to fuel or compression, right? Damn I hope these plugs do the trick...

-Brad

Jettagli16v · « **Reply #31 on:** March 05, 2009, 03:53:12 pm »

Update:
I keep hearing "cranking speed" in the discussion of a no start.
I got a new battery and starter today, and will install tonight and we shall see what happens!
I also bought 8 new heat shields in case I do need a compression test.
($1.22 ea, 4 for now, 4 for next time!)
Wish me luck!
-Brad

Jettagli16v · « **Reply #32 on:** March 05, 2009, 10:53:24 pm »

NOW,
I have effectively ruled out both the starter and battery. That should take care of the slow cranking speed theory.
The battery tested bad, and was replaced under warranty.
The starter did not engage and disengage smoothly, so it too was replaced.
After installing both, the car cranks more smoothly,
but still does not start.

Next stop:
Compression test?

(I wonder if this devolved from a troubleshooting thread to an inner monologue and nobody let me know?)

-Brad

clbanman · « **Reply #33 on:** March 05, 2009, 11:04:57 pm »

Are you sure you are getting fuel? Power to fuel shut-off solenoid? Can you hear it activating?

Jettagli16v · « **Reply #34 on:** March 06, 2009, 11:08:35 am »

Thanks for the reply!
I am not sure I am getting fuel,
though I can smell lots of it coming out from the exhaust during cranking.
I do have 12v at the fuel solenoid,
and can feel it clicking when activated.

I just bought a diesel compression tester, and the line wrench from VW usa.
I may wait for the wrench to show up, or I may give it a go with a 17 open end.

Any specific things to be careful of when removing injectors and lines for the first time? The Bentley really glosses over this subject.
Wont I need to reprime the lines and injectors after I re-install?

Thanks,
Brad

Jettagli16v · « **Reply #35 on:** March 06, 2009, 11:38:11 am »

I totally jascked that thread...
sorry.
I will now start a new one.
Thanks!
-Brad

vanbcguy · « **Reply #36 on:** March 06, 2009, 11:53:44 am »

Removing injectors:

YES there are things to worry about! The problem is the injector is a steel body into an aluminum casting that is VERY thin along the front of the head.

If they've been in there for a long time they're probably somewhat stuck. Hit them with some PB Blaster or another GOOD penetrating oil ASAP and give it some soak time. The more soaks the better!

Ideally you want to remove the injectors while the engine is warm - this will be a bit of a problem given your situation so you'll have to be careful. The issue is they tend to carbon up around the threads. When the engine is warm it increases the clearances in there a tad.

You'll probably have to use a breaker bar. The key is to AVOID putting pressure on the thin part of the head casting at the front of the engine at all costs. NEVER pull the breaker bar towards you, ALWAYS push it towards the head so the lateral force is going away from the thin bit of the boss. If you search around for "cracked injector boss" you'll find more than a few tales of woe...

More than likely you'll find they don't want to just unscrew - they'll move a bit and get stuck again. Treat them like a tap - loosen a half turn, tighten a quarter turn, loosen a half turn, tighten a quarter turn, repeat. The idea is to try and avoid galling up the threads because the set that will get wrecked is the soft aluminum head, not the hard steel injector.

If one gets really stuck, tighten it back up a bit and give it a GOOD soaking with PB Blaster and then walk away for an hour or so. If you're lucky you'll come back and find it much improved. The key thing is not to get carried away and try to force them - a broken head ends up turning a simple job into something MUCH more complicated.

Once they're out you need to remove the heat shields. I've personally had quite good luck here and mine have always come out somewhat easily. The best tool I've used is a strong magnet - since the head is aluminum which isn't magnetic the heat shield is pretty easy to grab. For the ones that are a bit more stuck I use an old bicycle spoke - the head of the spoke grabs the inside of the heat shield quite well. Other people have suggested using a large wood screw or cranking the motor over and having the compression blow it out. With any luck though they're not particularly stuck.

turborabbit · « **Reply #37 on:** March 07, 2009, 02:29:44 pm »

Wow, I've really been lucky-I'll be more carefull next time I pull injectors.
I didn't see mention of the special injector socket that makes the job much easier-Hasnet (sp?) for about $100-cheap if you appreciate the all-around beauty of these little motors. I prefer a 17mm Snap-on Flank Drive to remove the spider. Loosen #2 at the IP last-duh-and tighten the same first before attempting to attach any other unions. There seems to be a world of difference between starting compression and running compression, but knowing your compression values for each cylinder can save you a lot of the trouble I've gone through, avoiding the inevitable. It's worth it though-as much as I despise mechanicing, oil, grease, diesel and especially gasoline-I can't imagine driving any other vehicle than my caddy, until I go electric-good luck-warren :wink: