Buzzy engine. Injector??

[trev]

Rebuilt and installed a head on my 1.6 TD Jetta.

 Got the pump timed, and all put together, and it runs pretty well, if I do say so.

 Bit buzzy.

 It runs smoothly under fairly hard driving conditions, but not so smoothly at downtown acceptable speeds. If you know what I mean. It's not rough, just buzzy.

 I was wondering if this sounds like a symptom of one half-kacked injector? Or one out of whack with the rest, in any case.

 No idea how old the injectors are, or whether they were matched. Came with the head, on my parts car.

 I have a spare set of known high mileage injectors on the bench, and am considering swapping them in, but I would rather put up with this until I can scrounge up a new set of nozzles and make up a pop tester to set them up with.

 I also am only mostly sure that I got all four injectors from the same head, when installing them (I stripped the two heads at different areas of my bench, but there was some migration over the time frame).

 Belts are all tight, IP timing is on.

 The only other thing I can think of, is that I may have got the cam pulley off a degree or two while tightening things down, as I was using a slab of aluminum barstock for the lock. It looked good when I had it all tight.

 ??

 Cheers
  Trev

[Doug]

So check the timing again just to be sure. I would look for something that is loose and vibrating at higher rpm such as a bracket anchor bolt. Did you replace the cam belt idler wheel/bearing? Is the cam belt too tight?

[trev]

I should be able to get to the timing this weekend, and will post back the results.

 Belt tensions are all good.

 The vibe feels like it's from the engine itself, but I'll root around the engine again for loose stuff.

 Just seems, well, not quite even when it runs.

 Gotta get on those nozzles, I guess. I'm not keen on playing "swap the injector" as a troubleshooting method, unless I am really at the last hope.



 Cheers
  Trev

[fatmobile]

Check the like angle bracket that goes from the alternator bracket to the injection pump bracket.
 I've been breaking bolts on that one,... and when I do it buzzes/vibrates at about 2500rpm.