3.2 Carrera throttle body stop adjustment

[bcheney]

Can someone let me know how you can adjust the linkage so the lever is up against throttle body stop? See attached pic. I just installed my rebuilt 3.2 into my 89 Targa and I am idling at 2600...This is even with the throttle cable disconnected from the bellcrank on the side of the G50 transmission and the cruise control cable disconnected. You can see the gap between the arm and the stop in the mirror....I had to take the pic that way as my iPhone would fit into that tight spot! The car is still on the jack stands...can't wait to give her clearance to roll! The orange glowing ring at the top right of pic is from the small LED flashlight I used to brighten up things...

[ischmitz]

Have you checked what's preventing the lever from closing and hitting the idle switch? A properly adjusted stop allows the lever to hit the stop while at the same time depressing the idle micro switch. The idle switch is needed to get stable idle. Yours looks like something is preventing the throttle plate from shutting all the way. Maybe there is some gunk inside the throttle body obstructing the throttle plate. Or the return spring it not strong enough or the shaft needs lubrication. Or something else is obstructing the throttle lever. Hard to tell from your photo. I would remove the throttle body and examine it. Then once it moves freely put it back, and only connect the throttle cable and go from there.

Assuming no one has tampered with the adjustment I'd leave it alone. If you have to adjust it from scratch first you need to adjust the stop position. This has to be done with the ICV centered (by inserting a paper clip into 3-pin diagnostics plug). Think of the ICV as a variable bypass to the throttle body controlled by the DME. You want the engine to almost meet the idle condition with the ICV centered so it later has enough range to regulate idle. This is done with the engine at operating temperature. Once the idle switch is pressed the DME goes into a closed-loop mode. It regulates the ICV to maintain the 800 RPM or 880 RPM (later models).

Next, the micro switch might have to be adjusted relative to the stop so it gets depressed but not loaded up by the throttle lever stop. It can't be misused as mechanical limit.

Ingo

[DRACO A5OG]

Originally Posted by bcheney

I am idling at 2600...This is even with the throttle cable disconnected from the bellcrank on the side of the G50 transmission and the cruise control cable disconnected.

+1 above, check the idle switch is making contact with the lever arm. If not you will need to adjust it to insure it makes proper contact. If you can move it further to make contact with the switch then it may be your return spring/s there are 3, 2 under the manifold and the one at the TB lever.

Good idea to see if anything is lodged in the TB too.

Jim

[Chuck.H]

If I recall correctly, there is a little slop (not a Porsche term for sure) in that curved throttle arm as it connects to the throttle shaft, such that when the cable pulls on it, the arm first opens the throttle idle switch BEFORE the throttle plate actually moves. I think getting this right goes a long way to getting smooth low-rpm drivability.

Chuck.H
'89 TurboLookTarga, 382k miles

[JAR0023]

Linkage is two pieces. It moves a mm or so off the idle switch before the throttle plate starts to open.

Unless you dropped it on it's head I can't see that linkage being out of adjustment. I'd be looking for something binding.

There are multiple return springs. On at the throttle body and either one or two under the intake.

IIRC the arm from the throttle body linkage down down to the pivot console on the engine has a bend in it. It's not reversed is it? -J

[steely]

Set screw "E" need adjustment?

[bcheney]

Thanks to everyone who chimed in. I got working nicely now!

[DRACO A5OG]

Congrats!