Throttle adjustment

[Merv]

On my Carrera (1988), the throttle take up is slower than I would like.  There is a degree of 'nothing' when the pedal is initially depressed, then it all happens perfectly.  I like sharp throttle response.  On the earlier cars I have worked on with complete rod/ball/cup linkages I was able to adjust the system to my liking- from pedal to engine.  On the 3.2 with its electronic control of throttle response up to WOT, is there any degree of adjustment at the pedal end that can reduce the initial slack response?

[Peter M]

Merv,

If you talking about "freeplay" in the mechanism, then "yes" it can be reduced by adjusting the linkage freeplay down near the transmission.

If you are talking about initial engine response, ie the butterfly is already actually moving off the position stop, then "no" unless you dump the AFM and upgrade the ecu.

In all cases always check the clamp on the air inlet elbow on the throttle body is not fouling the throttle arm and preventing WOT.  You would be amazed how many 3.2's suffer from this.  

[Merv]

Thanks Peter.  I have already replaced the bushes and tightened things up in the linkages in bell crank area of the tranny.  It seems that I will need to delve more into the WOT process and make sure that there is no hang up there.

[autojack]

I've had this bookmarked for a couple of years, planned to do it myself, but then Dave Brennan sorted it for me when he came to do a general service.

http://forums.pelicanparts.com/porsche-911-technical-forum/461311-throttle-cable-adjustment-how.html

[Merv]

Nice thread. Similar to the early cars with rod length, fulcrum angles and bell crank bushings all in play.  Except for the WOT switch arrangement and electronic peripherals on the engine.

I checked the throttle action this morning.  With the pedal fully depressed I have at 1.5 - 2cm of action still remaining on the butterfly.  That seems excessive.

I will check the throttle end first.  I hate crawling around in there!

 

EDIT: I was able to get an extra cm on the rod attached to the pedal and that gives better clearance at the back of the pedal from the number of layers of rubber, pedal board, carpet, etc., that are there. Now I am getting WOT at the butterfly and the response is faster with a slightly longer pedal travel.

[Harry]

Hi Merv,

Just been through the same issue with my 86 Carrera.

1. Get an assistant to depress the accelerator pedal as far a it goes, check to ensure the throttle is opening fully. If not adjust the slack in the cable.

2. Check that the WOT switch is operating as it should, it should make contact at about 75% throttle opening. Remove the connector and check continuity across the top two pins, the switch should close @ 75% if it is not closing rotate the switch clockwise until it does (place a large flat screw driver on the mount and hit with a hammer 😄)

3. Get in touch with Steve Wong and buy a chip, wow, what  difference it made to my car in throttle response, power and civility so smooth and really makes a huge difference.

 

Cheers,,

Harry.

 

[Airhead]

I was happily driving my 3.2 and thought it went pretty good. David from Nurburgring Mechanical did a couple of jobs for me found it was only getting part throttle. About 2/3rds he said.

Shit. It goes well now. 😀

[jnr356]

was it previously serviced in heidelberg?

nearly every one comes out of there with a  hose clamp interfering with the throttle linkage