I am currently finishing a auto to 5-speed swap on a S5 convertable. I am having issues with the car not wanting to idle and not starting with out a little shot of carb cleaner in the intake manifold. I was on IATN and posted about the car. some one mentioned about how the auto computer has input on cold start enrichment and the ISC valve. has any one ever run into this or performed this swap. I tried a dearch but came up empty. any help is greatly appreciated.

Thank you.

 

I read somewhere that not wiring up the neutral safety switch can cause a rough idle. Now, this doesn't make sense to me and I didn't do it when I made the swap. I did however, unplug the auto computer.

What's a "dearch"? lol

Brian

 

Mine was an s4 but i removed the auto computer allgether.

 

A few years ago I swapped the auto trans for a manual on my S4. Its been a while so check the schematics in the FSM or Haynes manual to verify my next statement. I believe that on the back of the throttle body, there is a vaccuum hose that goes down to the auto trans vaccuum modulator. With the manual trans, this hose is not needed. You will need to get one of those little rubber nipple cap things to block off the vaccuum port that the hose used to attach to on the throttle body. Also, you may need to adjust the idle on the throttle body because the engine will have a different load on it now that it is not spinning a torque converter full of fluid. On S5 cars, their is a computer for the auto tranny that interfaces with the main ECU. This should be unplugged and/or removed. I don't remember if my S4 had one but I know the nuetral safety switch nor the reverse light wiring should not affect the idle. Hope that helps.