alrite, i was drivin, and i notice that when its 'half' warm (idle not yet down to 750) the idle goes up to 1600, then sputters, and down to 1300, then smoothly back up to 1600, then sputters, its about a 2 second interval...neone know whats goin on?

thanks,
Jeff

 

The TPS (Throttle Position Sensor) is need of adjustment to spec or replacement.

 

the tps is external to the throttle body right?

 

Here's an easy way to find it. Find your throttle cable that runs around the engine. Follow it to the throttle body. On the other end you'll see 1 (S4) or 2 (S5) plungers that go out when the throttle cable is pulled. Really easy.

 

alrite, so should i shouldnt have to worry about a low compression since it seems to lose rpms? (sorry..havnt eaten today, so im a lil wacked out..haha)

 

You mean that the idle when warm falls every now and then?

 

no, it seems to idle high (1500) and sit there for a sec, then drop to 1300 (noticable difference) then speed slowely back up to 1500, then drop to 1300. its kinda pathetic..like its trying to reach 1600, but before it gets there, it just dies and goes back to 1300..then 1400...1500...brum...1300...etc..

its weirding me out

 

hhmm.. i dont know what that is all about, but, your idle is considerably high compaired to my 88, and other S4s i have see, my idle is steady (give or take a little bit) 700RPMs, same with my freinds 88 and 86 SE..... that may not have anything to do with it... just thought i would mention it

 

So does it idle fine when it is warm? Turn your headlights on. What happens? The idle should dip and pick back up again. It could be voltage regulator. What is voltage reading?