I just got a motor rebuilt and in a car, and I started cranking it and it turns out that the spark plugs are only firing part of the time. I've been looking at the tach since the tach signal comes from the ignition, and the tach only jumps while it's cranking part of the time. The ECU is throwing a code, but I can't find a list of S4 NA codes. For a s4 turbo, it would be the IAT sensor.. except NA's don't have that so it has to be something else.

 

Mine did the same thing, I replaced the CAS and cleaned up the ground under the intake manifold and it was fixed.

 

okay. This isn't my handle (i'm powrdby13b) or my house so I'm gonna have to go check that out here in a bit. Thanks a lot man!

 

n/a's do have an IAT sensor. Go to either of these websites, has alot of info on both s4 and s5. http://howto.globalvicinity.com/gv_w...wi=2&co=1&vi=1
www.rotaryresurrection.com

also i am pretty sure you need the LED's to get the codes off of an S4.

 

Spark plugs are fouled?


-Ted

 

This could be....try doing voltage drops at the coils