I still think you may have an vacuum leak somewhere, but I also think some other components are still broken or way out of range. So it's a combination of some things. When I adjust my bac with the engine running it doesn't do anything unless I turn it too much and the car dies. But I aquired decent idle from fixing a vacuum leak and adjusting the TPS. I think your TPS is still bad possibly.

On another note I was looking through the FSM (Factory Service Manual) and I saw that it says to put an adhesive on the top of the adjust screw of the variable resistor AFTER you adjust it. I guess they do this to keep it from moving or to stop people who don't know what they're doing from changing the setting. Maybe that is what is wrong with yours. It just has some adhesive on top of the screw. Check for yourself on page 4B-82 of the FSM. Here is a link to the FSM.

http://www.teamfc3s.org/main/factory...TEMS_TURBO.pdf

 

i think its a problem with the BAC, because sometimes the IDLE is alright, then the car dies and then the IDLE is jumping up and down... when i have a VAC leak it would "continuously" suck... or not?

why should my TPS being bad?

it has no jumps or out of range readings ... and a maximum resistance of 6.2 kOhm... (FSM says that it would be bad if it reads over 6.5 kOhm)

i also have a little (very little) exhaust leak in the precat... but where the precat meets the maincat (after the O2 sensor)... but i think this wouldn't be the greatest prob...

but VAC leak... what should i check exactly? there are millions of VAC lines on the S4 *grml*... is there a good graphic where ALL IDLE-related VAC lines showed?

and there is also no adhesive on the Resistor... it looks to me like somebody had broke off the head from the bolt :/

other question by the way...

is it possible to IDLE the engine without that creepy ****? mechanical?

 

I NEVER check the resistance of the tps with the engine running.

I'd suggest leaving the connector connected to the tps........fully getting the engine Hot...........and reading the output of the TPS at the ECU (green/red wire). It should be apporx 1vdc at idle. Or backprobe the green/red wire at the tps with a piece of spare wire a foot or two long (so you can leave the intercooler on), and monitor the output with a meter while the engine is idling.

Or set it per the FSM using two LED's inserted in the green check connector. Either way works.

Your problem probably lies elsewhere than the TPS. What kind of idle speed do you get when it's under 1100 rpm?

If the idle is over 750, installing the initial set coupler will most likely NOT effect the idle of the car. IF you installed the initial set coupler and the idle did not change, then there is something other than the BAC that is setting the idle, like what was suggested above.....a vacuum leak.

Or someone has been messing with the throttle stop screw, or ?????

http://www.teamfc3s.org/info/articles/idle.html

 

i will check tommorow how much Voltage i have @ IDLE... don't need to meassure it at the ecu, i can see it on my SAFCII

i will also change the Resistor and the BAC again used parts which are of a complete stock motor and with complete stock screw-positions + checking the TPS output ... i think this would be a good point to eliminate this 3 parts as a mistake what do you think?

 

I'm sorry I didn't read that you had decent idle so I'm guessing at least you don't have a big vacuum leak.

Doing all those things would likely rule out TPS, variable resistor, and hopefully BAC.

I have a question? Does your car's engine speed up when you first turn it on?

Does the idle bounce around by itself from 1000 to 1500?

 

sometimes i have the complete 300rpm coldstart routine, sometimes he will IDLE for the first few minutes about 1500rpm, sometimes at 1100... its really weird, sometimes he also IDLE's "good" (with a minnor jumping of 50-80 rpm's)...

my personal tipp... the BAC don't works every time right... i've already cleaned it with brake and rustcleaner etc. but nothing helps...

also my Variable Resistor is definitly shott... the replacement Variable Resistor has the following readings...

A-B 5,3 kOhm (isnt covered in the FSM)
A-C 1,4 kOhm
B-C 4,1 kOhm

my Variable Resistor don't give readings between B and C so i think its definitly a weak point in the system... maybe some internal damage between the terminals and trough the engine vibrations sometimes connection and sometimes not... how knows? but its definitly a point too start i think

also i get behind the screw problem... it seems that european engines have other Variable Resistor... wie need a "special" screw Driver too adjust the resistor

 

@Hailers

i have 0.54Volts output from my TPS...

should i try too tune the TPS via my SAFC to get IDLE readings from 1Volt?

 

soooo, i've had a look at the outputs...

its a little bit confusing...

when my engine is completely cold, the Cold-Start IDLE is ok (3000 rpm)

after cruising around, i have a TPS output from 1 to 1.1 Volt...

but after the car warms ab a little bit more, i only have a output of 0,2 to 0,25 Volts...

soooooooo... should i try to turn the car on, wait until i have this outputs and try to set the TPS with the engine running and a helper sitting inside the car who checks the output from my TPS!?