Hey guys, I work at Subaru and I've been using shop time after hours to detail my car and do small jobs. Since it's the weekend, I was allowed 4 hours of shop time so decided to get cracking on the bigger issues such as my ebrake and exhaust leak. Anyways, so i took care of the ebrake issue. Now the other issue being the exhaust. I had a leak from where the mid-hangers are welded to the mid pipe and the gasket from the manifold to the downpipe was missing so I was pretty much using just the manifold to exhaust any fumes and whatnot so it was quite loud. Anyways, I cut a exhast manifold in half and drills a hole along with minor modifications to the gasket to make it fit and used exhaust cement to help with sealing. I also changed my CAS with a non-cracked one, but the car wouldn't start so i changed it back and it started again... however at 3200-3300 rpm, there's a fluttering sound and the revving doesn't sound at all smooth. What I want to know is what would cause this? The CAS timing, Exhaust (lack of back pressure at the leak since now the flow goes past just the manifold), or something else. Any help is much appreciated! Please ask me questions if I'm not being clear.

 

your other CAS was faulty and now your timing is out.

 

Exactly my thinking, get a hold of a good CAS, install it and then set the timing. If after all that it still gives you a bit of a missfire at 3500RPM you can try this. I was told that there is a grounding issue on the FC's that will cause a hesitation or missfire at around 3500 to 3800RPM. Just run a fairly heavy wire (I used left over wire from installing the power cable for my sub amp) from the engine to the chassis, and then from the chassis to the battery. Give it a try, I don't know if that is 100% true, but it seemed to work for me.

 

Can someone please post a step by step procedure of how to set base timing.

 

The man:
http://www.aaroncake.net/rx-7/grounding.htm