Here is a video about freeze plug installation, they are pretty much the same on all vehicles so the process is what you want to pay attention to.
If one is rusted you might as well replace them all and that requires removal of the engine
The timer relay for glow plugs on a 86 Jetta is under the steering column. It is located in slot ten.
Yes, but you'd be better off with a 2003 Jetta
Replace the exaust manifold with Turbo charger and dont forget to install the oil line to the turbo otherwise u will ruin the turbo as of dryness.
http://volkswagen.msk.ru/vw_doc/eva2/
.045
If you're using platinum plugs, don't worry about the gap. Install them right out of the box. Gapping them will destroy the platinum and they won't fire correctly. It will not run.
.035
.045
Red means STOP. Your owner's manual will have the description on what the ? means.
no
There are none. I believe they use a perma gap plug.