I've tried to set timing and idle on this car for weeks and it will not idle correctly. I have a FSM and Haynes so please no "look it up" comments. There is no BAC on the car anymore. The previous owner stripped everything emissions off and blocked everything off. It's a S4 GXL with a T2 swap. The only thing that changes the idle is playing with timing. When I set timing per factory specs it will barely idle (around 500 RPM). if I advance the **** out of it (Like 30*) it will idle smooth, but around 1500 RPM. To top it off it overheats in seconds and I think it's because I need to advance the timing 30* just to get it to drive.

Any ideas would be great. I'm thinking about trying to get everything back to stock to fix it.

there are no vacuum leaks.

 

Hi Adrian,
Have you made any adjustments the the throttle body or TPS?

 

the throttle body was modded(Previous owner), so it's all hacked together. The TPS is at 1k OHM when engine is hot.

 

You/someone removed the primary method of increasing the idle speed............the BAC has been removed. The TurboII BAC has a air bypass screw that would have let you increase the idle speed.

An alternate method is to remove the intercooler. Find the throttle stop screw and backoff it's 8mm wrench size nut and then screw it towards the linkage to increase the idle speed.

JPGs attached are of a series four throttle body. Series five MIGHT be different. Remember, the screw I talk about has no spring. Just a 8mm jamnut and screw being held in place by said jamnut.

I did a search using HAILERS and THROTTLE STOP SCREW as input. Using HAILERS2 didn't cut it.

 

what if its a jdm throttle with no jamnut how do you adjust

 

Don't be asking me hard questions. I only do the easy ones.

 

that should be how u adjust idle, thats what im using, seems to be working. the jamnut screw is under the throttle body on s5 modles. they reversed n/a and t2 throttle bodys for idle adjust? im gona see how mine is since i sealed up some vacum holes. if any one else has some info please let us know!

 

So turns out the kid put an NA throttle body. Could that cause the issues? I'm swapping on an extra T2 TB I had. What all needs to be hooked up for the BAC to work?