Hi.
My TPS wont stay set and my car now has the ever frustrating pulsing idol between 1000-1500rpm.

Ive just finished modifing a S5 TB to go on my S4. by modifiing i mean i did the throttle plates removal (as per FC3s pro ) at the same time as this i attempted to modfied the throttle system to take the arm for the OMP.
to do this I had to cut a few things down, and more than likely, this is why it wont stay set.
the things i cut down to fit and why were:
the bushing of the OMP arm that activates the rod which controls the OMP. I did this because ( as experienced people will know ) on the S5 TB the pin that runs through the TB and holds the throttle plates etc is consideraby shorter on the S5 than on the S4, so i couldnt just add the OMP arm on there as then other things wouldnt fit.

The S5 TPS adjuster arm. not the front one with the adjusting screw going though it but the rear on which is presses against. I cut some of the meat from the arm to allow the OMP arm to move more freely as it was hitting against the TPS adjustment arm.

I did all this because i had a S5 TB with TPS and i wanted to do the TB mod and then seperate the TPS out and use the S4 part as per standard ( done buy actualy swaping in a S4 tps so it had the correct plug already )and then to use the S5 full range for my SAFC so it could use the map sensor signal for ajusting my FCON but also have a full range Throttle % reading at the same time.


your probably just gona say, pull it all apart again and put it back the way it was but i dont have a S5 TPS adjuster arm or a S4 OMP arm so im kinda stuck on both counts in some respects
I guess the ther option is remove the OMP and run premix and then just find a replacement S5 adjuster arm.

Your thoughts?

 

Hmmmm.....did you mess with the rear of the TB as far as the fast idle cam is concerned?

I had trouble adjusting my TPS because the cam wasn't releasing and the throttle wasn't closed even when fully warmed up. I used a flat screwdriver to move the cam out of the way...you will see the plates rotate a hair and close further.

Another more common mistake is to push on the adjusting screw slightly while adjusting the TPS arm and thereby having the throttle slightly open. Hope this helps.

 

yes i removed the fast idle cam etc when i removed the front throttle plates etc.

I was being very careful not to push on the screw as like you say it opens the throttle slightly. The actually adjustment arm is flexing because i cut it up abit and thats causing the tps to go out of adjustment every time you move the throttle.

Its a new adjustment arm and getting rid of the OMP and going premix for me i think.

 

so. I swapped out the S5 1/4 throttle TPS for the running S4 TPS from my last S4 TB that a took off adn ive still got a surgind idle. i set the tps and its sitting around 1ohm +\-0.02/3 ohms

maybe ive got a vacum leak aye.