I have a 96 a4 2.8 Quattro and the engine was running fine I was driving down the road and it died. The car will run but barely. Got the car back to my house. I changed the spark plugs, wires, and coil packs because upon taking out the spark plugs the entire right bank is not firing they were completely black and the drivers side was burning fine. After changing those things the car still will not run right. It has a newer fuel filter and a brand new fuel pump as well. Does anyone have any suggestions of what this could be.

 

If it's the entire bank, my first inclination would be either a vacuum leak or that sides o2 sensor.

 

Was it running OK before, and just suddenly crapped out? Because of the shared coils between banks, it probably is over-fueled, and as Eldude speculates, that points at the pre-cat O2 sensor. If a faulty sensor told the ECU that the mixture was way too lean, it would add opening time to those injectors. You might try just upplugging the pre-cat O2 sensors, and see if the engine runs better. However, you really, really need to scan for fault codes.

 

When I was chasing down issues in my car I bought a fairly cheap portable scanner. Very much worth $ to have access to code info anytime, be able to reset codes, etc.

Note: the one I got does not define all of the codes, but they are can be googled easily. Still worth it to have hand held access to codes for less than 1 hour of shop time/charges.

I didn't shop around much so there may be better options available. But.....

I got:

Vag405 max scan ~ $45 on amazon

 

Well after more diagnosis and a couple scanners I had a code that came back as O2 right bank. So I figured it could be that but after I found the code I wanted to do a compression test. 160-180 on all drivers cylinders and I have 60 on all three of my passenger cylinders. I'm thinking I have a blown head gasket on the right bank

 

From what I hear, that's actually a feat. Evidently the head gaskets on our cars are pretty dang robust.

 

All three cylinders low and the same are more likely a cam timing thing, not head gasket.

 

Well you are correct opened up the front of the motor and the left can gear is about 4-5 teeth out of time. Any idea what could have caused this to happen. Timing belt job was done around 15,000 miles ago.

 

Was the belt loose? The '96 doesn't have a spring-loaded tensioner, so once set, the tension stays set, unless the tension roller bolt loosened. You need to put it back in time, then cross your fingers and run the compression check again.