Loud ticking/tapping/knocking from 1.6 IDI 81 jetta

[R.O.R-2.0]

I know you don't want to think this hard R.O.R. but how many times does the fuel get compressed between the intake of the IP and the output of the injector bodies. 

Does the vane pump compress then inject to the secondary then in the internal pump in the head then again at the injector?  Does the injector count at all because it only recieves a compressed stream of fluid and reacts to it?  I think the name is misleading, true it allows the fuel to enter the cylinder but does it actually inject it? 

I know nit pick, nit pick.

I think for bubbling at the threads most any liquid would do.  Water, WD40, brake clean if you are fast enough to see it, watch the flash point there.  The use of carb cleaner was more accidental than anything else. 

MY 2 pennies

im talking about the actual INJECTORS.. not the various pumps that are used to feed them.

there are only 4 primary sources for the engine to receive fuel, and that is thru one of the 4 injectors..

there is nothing else on the engine that even remotely functions as a secondary fuel injector, in any way, shape, or form..

the various pumps TRANSFER fuel, as well as pressurize it, so the timing advance can operate, and the pump head can more easily operate with PRESSURIZED fuel at the inlet of the pump head, rather than relying on vacuum to suck the fuel into the pump head to be transferred one final time, thru the delivery check valves, thru the injection lines, and finally, shot thru the injector as a finely atomized mist, and burned by the engine..

tank>lift pump(if equipped)>vane pump>pressure regulator>pump head>delivery valves>injector lines>injectors..

so, to really NIT PICK, the fuel NEVER gets compressed, being that liquids do not compress 

im sorry Dale, but sometimes i feel the need to REALLY THINK (basically over-analyze) about things, and throw out the most smart-assed response i can come up with..

i mean no hard feelings either, like i said, im just being a smart-ass, that was just meant to be humorous, because you commented on me not wanting to think too hard about things.. so i took it one step further, and got some-what technical with my response. lol..

[Krisverde]

Yes that's right. I just know the bentley shows upper and lower body of the injector. Anyways I sprayed around the area again and made sure to stay away from intake... No change in idle speed.

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so, it was just getting a WHIFF of vaporized carb cleaner to the intake air.. that would definitely account for a rise in idle speed..

being that the injector, and pre-chamber are both under VERY HIGH pressure, i didnt see how the engine could actually ingest enough carb cleaner thru the injector threads to actually change anything..

That's what my thought was too. I just wanted yalls opinion on it to confirm haha.

Is it worth checking the compression on the engine? I mean it's been running "smooth" besides the ticking. I can't believe I don't have feeler gauges.

[R.O.R-2.0]

Yes that's right. I just know the bentley shows upper and lower body of the injector. Anyways I sprayed around the area again and made sure to stay away from intake... No change in idle speed.

Sent from my BlackBerry 9780 using Tapatalk

so, it was just getting a WHIFF of vaporized carb cleaner to the intake air.. that would definitely account for a rise in idle speed..

being that the injector, and pre-chamber are both under VERY HIGH pressure, i didnt see how the engine could actually ingest enough carb cleaner thru the injector threads to actually change anything..

That's what my thought was too. I just wanted yalls opinion on it to confirm haha.

Is it worth checking the compression on the engine? I mean it's been running "smooth" besides the ticking. I can't believe I don't have feeler gauges.

cant hurt.

[ORCoaster]

R.O.R.  no offense taken on my part.  I was kind of going under the assumption that to inject something was fitting of number 1 of this definition:

'inject
[in-jekt]   Origin
in·ject   [in-jekt]
verb (used with object)
1.
to force (a fluid) into a passage, cavity, or tissue: to inject a medicine into the veins.
2.
to introduce (something new or different): to inject humor into a situation.
3.
to introduce arbitrarily or inappropriately; intrude.
4.
to interject (a remark, suggestion, etc.), as into conversation.
Origin:
1590–1600;  < Latin injectus  past participle of in ( j ) icere  to throw in, equivalent to in- in-2  + -jec-  (combining form of jac-  throw) + -tus  past participle suffix

Related forms
re·in·ject, verb (used with object)
un·in·ject·ed, adjective

Seems we both tend to inject comments here as in number two and four.

I was thinking that as the fluid moves along its path from tank to engine there are a number of places where the pressure goes up therefore it was "injected" 

At the final end though when the fuel is sitting at the injector is it not the pressure from the pump head that actually moves fuel in small increments down the line?  Kind of like packing a papertowel tube with a sock.  Stuff some in and when you start a second sock the first has to come out.  I never thought that the fuel being shot out the check valve made it all the way to the injector. 

Thus in my mind the injector never actually increase any of the fuel pressure at all does it?  It just reacts to the pressurized fuel coming down the line and when it exceeds the spring pressure internal to the body it pushed up on the pintle and out comes the fuel. 

Like getting a shot.  The needle is a pipe and the syringe is the compressor.

Yes?

[Krisverde]

Made another vid. This time you can hear the sound better. http://youtu.be/VLazfaGfO8M

#1 is leaking from the part where it's threaded into the head and where the nozzle housing threads on. Looks like ill just need to tighten them up. # 3 has a slight leak from the same place right in the middle. If that makes sense. That would tell me why it bucks a little on higher rpm's and I mean rev it out. Either way i'm sure these are simple fixes.

[745 turbogreasel]

I'd stop the leaks first.  Next listen to each injector with the stethoscope.

Was anything done to the injectors?

Unless they are new, the rubber return hoses love to leak after being disturbed, and are often mistaken for an injector leaking.

Phones are pretty good about filtering noise...Broken valve spring might be a possibility.

[theman53]

It could be that a valve is sticking open from being miss timed at one point in life. It sounds something like that to me from the phone vid. I don't think it is rod knock, I would say valve for sure. Check and recheck the timing. If needed pull the head and inspect. At that point you could take it to a machinist and have him look at it too.

The injectors could make a sound like that. I have heard them make some bad noises, but never over the phone vid. Hard to tell. What is the IP static timing set to?

[Krisverde]

Head needs to come off tomorrow. Something oh so fun happened and the engine no longer turns over. Yes there was oil in it LOL.