Car runs on 4 cylinders instead of 5 why? - 1990 Audi 100

It is possible that you may have two coil packs going bad as cylinders 3 and 5 are on different packs. To attempt to prove this without going broke, you could swap the 1/4 coil pack with one of the other two and see if the misfire changes the 1 or 4 cylinder instead. If it does, you have the issue resolved. See the diagram below for more details.



If you can't read the coil packs on the right, they are paired from top to bottom as 3/6, 2/5, and 1/4

usually a miss fire is cause by a bad coil or wire if u have the single coils in each cylinder if u code read it it will tell u which one is bad ....if coil pack then could be it needs a new set of wires and yes it would run shaky cause instead of running on 6 or 4 its running on 5 or 3 which throws off balance o rotation just light an uneven load in the washer

What did the spark plugs look like when you took them out of cylinders 4 & 5 that you say are not running. If they are wet and black and smell like gas, I would guess you have back spark plug wires going to those cylinders. If they looked about the same as the other cylinders, or a tannish color and dry, then I would guess injectors.

you could have a broken motor rod,if not broken it will soon.

The 1995 Camaro did not come with a 3.1 V6, but instead a 3.4 V6.
Assuming this is what you meant, the correct firing order is 1-2-3-4-5-6.
Here is a representation with the cylinders labeled in order. 5 6 3 4 1 2 ---nose of car---

Firing order: 1-4-2-5-3-6
Below are the cylinder numbers:
Rear of vehicle 3 - 6 2 - 4 1 - 5 Front of vehicle

Get a compression tester and find out if you blew a cylinder. You'll need to test all cylinders. Your most likely running on 7 cylinders instead of 8 or 5 instead of 6 if you have the V-6.

what leads you to believe that your engine is running on 5 cylinders instead of 6

Did you mean 3100 engine instead of 3300?

1-3-5-6-2

By-the-way, the ODD cylinders 1-3-5 are on the side of the engine closest to the firewall, with the number one cylinder closest to the passenger side of the vehicle and the number 5 cylinder closest to the driver's side. Obviously, the EVEN cylinders 2-4-6 are on the side of the engine closest to the front of the vehicle with the number 2 cylinder closest to the passenger side, and the number 6 cylinder closest to the driver's side.

BROKEN VALVE SPRING WOULD BE MY GUESS.