I have a 91 RS V6 3.1 L. My question is I have tdc on number 1 cyl but rotor button points to #4 cyl.
Thankyou
P.S I am new to all this stuff

 

... which means you're either actually on TDC #4 or your dizzy is 180* out, in which case you need to march your plug wires around the cap 3 terminals. You'd need to pull a valve cover to verify this.

 

In a four stroke engine, the #1 cyl will reach TDC twice for every 360 degrees of crank rotation. In other words, you were probbaly seeing #4 at TDC since that's the pair for #1 (one will be on intake, the other will be on exhaust). Rotate the engine another 360* and your dizzy will point to #1 --- both the cam and distributor will rotate 180* for every crank 360.

 

 

Your timing chain has a gear on the cam that is 1/2 the size of the one on the crank, SO

When the crank rotates once, the cam goes 1/2 a turn. The cam drives the distributor so it's rotation matches the cam. Since your cyl needs to evacuate the exhaust gasses, it needs to move up with the valve open to push the exhaust out. Then it goes back down and draws fresh air and fuel in as the intake valve closes. When it reaches the top the intake valve is closed and the spark plug fires. Then when the piston hits bottom the intake valve is then again ready to open, and opens as the piston travels back up to expel the gases. Since the piston is at top dead center twice, you are reading the exhaust TDC and not intake (where the spark is happening).

http://auto.howstuffworks.com/engine1.htm

 

think you meant exhaust valve here

 

thanks

It's sure easier to explain something like this in real life, rather than try to type it out, that's why I included the link.

 

I got the car running today but now I am getting code 42 and 43 .Thankyou for any help