I jsut put my new rebuilt engine in and my trailing are not firing??wat can be the problem..also will s5 trailing coil packs worj on a s4

 

Sure they are not firing??? Is the Tach working?

 

Yes, s5 trailing coils will worj in an s4 car. What are your symptoms?

 

well the tach moves slightly but when I put a screw driver in the plug wire tehn ground it I dont get any spark

 

Your leaving some things out. Does the engine start or not? If it starts then tell us if the tach works normal.

No start and a jumping/bumping tach means the trails are firing.

Trail plugs/coils are not required for starting a engine. The only way you would notice is if the tach did not work.

 

the tach works but I think the reason my engineisnt startingis b/c I have a vacum leak the tach does work but I groudn them and it doenst spark

 

FYI.........The tach works off the trail coils Working and firing. Movement of the tach needle therefore most likely means the trail plugs are firing. Something like that.

A engine will start just fine and dandy without the trail coils working or not. Concentrate on the lead plugs and Flooding and the right timing.