VW Mk2 1.8L 8V vs. Mk3 2.0L 8V cam gear questions

My friend has a 1996 Mk3 Golf with a 2.0L 8V engine that his son drives to school. A couple of weeks ago the belt snapped at low RPM. I have seen conflicting information as to whether or not this engine is an interference motor. As best I can tell it is interference, but just barely, so if the belt snapped at low engine speed there is a very low chance of damage.

My friend is quite skilled mechanically and is trying to show his son the ropes, so he had his son tear down the car for belt replacement. The car has an aftermarket adjustable cam gear. In the course of stripping the side of the motor down his son got the adjustments on the cam gear all jacked up. They put the belt on but the car wouldn't run.

They have a 1990 or so Mk2 Jetta with an 8V motor (probably 1.8L). They pulled the stock cam gear off the Jetta and installed it on the Golf motor. The car still won't run. My friend tried adjusting the cam gear a couple teeth forward and a couple teeth back but the best result was a sputtering attempt to start.

I did some looking around on Rockauto.com and learned the cam gear for the 1996 Golf was used on a whole bunch of VW models, but NOT Mk2 Jettas other than the 1985 GLI model.

Does anyone know what the differences between these cam gears might be? I'm thinking maybe a different number of teeth, but it could be as simple as the timing marks being different.

My friend thinks the cam gears are probably the same since the gear fits on the cam and the belt fits on the gear. He thinks maybe the car has an aftermarket cam since it has some other performance parts (intake, header, suspension, wheels).

My friend has helped me out with car problems when I have gotten in over my head more times than I can count and I'd like to be helpful in this case.

Here is a picture of my old 1991 Escort GT in pickup mode for your troubles.

from what my co-worker is telling me, the distributor also has to be lined up as well... so check your distributor timing

The VW watercooled 4cyl cam gear was the same from 75-98

Yup, same gear.

Rusty rabbit makes a good point. The distributor is driven by the intermediate shaft, it's super easy to spin that puppy a bit when doing the timing belt. The ignition timing is determined by the ecu based on crank sensor signal but the distributor needs to at least be in the correct ball park in order to work.

Also, check compression.

I have a rebuildable long block if you need one, pretty cheap.

Don't feel bad... I couldn't get my 8V to run when the timing marks were all messed up. I had to read the manual carefully and line everything back up. It was off LOL. Like the others have said - even the distributor has to be lined up. Make sure you're lining up the proper marks on the cam sprocket. There's an inner and an outer which is different! If you have it flipped around it will also drive you nuts. Finally got is started and running about a month ago.

On the ABA there's no adjustment on the distributor like the earlier cars so it has to be right at the int shaft. Make sure the rotor tip is pointing directly at the notch in the distro. It will almost point to the back of the block at the end of cly 4 (1-2 o'clock).

Also if you've pulled the cam gear off, it can be installed backwards and the timing marks will look right, but be entirely wrong.

Every ABA I have seen that broke the belt had at least a couple of bent valves. Did they check the compression?

I broke a belt on my ABA/Digi hybrid at 6200rpm and it survived. It depends on where things are when the cam stops.