If it's standard shift there's a plastic cap on the top of the bell housing. The there's marks on the flywheel and a pointer. You may need to unscrew the outer plastic part to see the pointer.
JoBo
Ok, this seems so silly. I normally work only on Air-cooled...but the daughter's home from college. I went to replace her cap and rotoron her '90 Jetta GL (1800 engine), and wound up dropping a piece of something into the distributor. Long story short...I had to take the whole thing out to shake the silly thing out. Now I realize I have no tune-up data, and can't find a mark on a pulley to save my life anyway. So...how do we set timing on a 1990 Jetta? It's 40 miles to the nearest auto parts store, so I'd hate to have to travel all that way just to buy a book today. Any help is deeply appreciated.
And you don't do it at idle either unlike most cars. That '90 Jetta (if it's not a 16V) is probably Digifant. You need to set the timing at about
2500rpm so have someone in the car keeping up the RPMs for you.This Is how I know to do it if it a digifant fuel system:
Warm car to operating temp, unplug blue coolant temp sensor at the top of the block , rev car three times past 3000 rpm to clear computer, maintain
2500 rpm while viewing mark on the bell housing after removing green inspection cover, set timing to +6 deg mark , plug sensor back in and you're done .MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.