Can anyone tell me where the fuel quality switch is on '87 DME.. part # would be 944.618.121.04 ? I think its the same for '85.5 - '87 944 including the '87 924S. The last time i had the DME out i dont think i saw anything that resembled the switch..but maybe i overlooked it on the casing. Can the switch only be reached with the DME taken out of the case? Ill check case again tomorrow.. but im fairly certain i didnt see anything.

Secondly, can anyone post a picture of the 'tool' i need to fabricate to change the setting?

For a few reasons i still feel like i am not getting optimal fuel mileage, 300miles and i get maybe 20mpg if i dont open it up to often with mixed driving..maybe 1/4 of it being highway. This is when i run both the FRWilk chip and in stock modes.

Ive changed everything that could relate to milage already..so i am down to the FQS and readjusting the wiper arm on the AFM.

 

It's on the inside of the DME obviously but there is a small stick-um cover on the outside of the aluminum case. Remove the stick-um and you will find another of Porsches wonderful inventions...a triangular socket that can be turned with nothing but some tool that fits. I used a small torx head screwdriver through trial and error. Turned all the way CCW is position zero, each click CW increases by one.

Yes your mileage is suspect. I get 25-26 mpg avg. even on a hard run with the Turbo and a consistent 26-29 mpg on the 83.

 

Okay thanks Steve, i probably over looked it with the cover on it. Ill take a look at it tomorrow. I am really hoping this is the cause of my crappy gas mileage.

 

For the record a small flat-head screwdriver does the job wonderfully.

 

Be sure and count how many CCW clicks it takes to get to zero. You can mess things up pretty bad if you don't have that reference point. A lot depends on what the recommended setting is with any chip set. On the Vitesse AFM chip it's 0=if # 4 pings, 4=normal if no ping; subsequent settings are 1/5; 2/6; 3/7; and 4/8 depending upon what injector size used. The lower of the paired settings for Vitesse is a timing retarded setting to eliminate knock based upon fuel quality. There was a post of what the OE factory settings mean about 5 months ago. Did the FW chip come with any massaging of the the FQS switch for fuel quality/injector size?

 

http://members.rennlist.com/951_racerx/FQS-adjust.html

Click thumbnails for bigger shot.

 

Thanks for the pictures Testarossa, those help alot!

Steve, as far as i know the FRWilk chip is supposed to be on the stock number '0' setting.. i just looked over the instructions and it makes no indication i am supposed to switch anything. Its pouring rain right now so ill have to check it later tonight. Thanks alot.

The thought of this being the reason of my crap mileage is making me excited, could it be i will see more than 20mpg on a tank??!?! The suspense is terrible... i hope it lasts..

 

This is VERY timely... my in-town mileage on my 87 S **SUCKS**, and the car seems to run a bit rich. Plus, when it warms up, it seems almost like the timing is slightly off; the belt is close to needing a regular tightening (been about 12K since it was replaced, new, with head work). Sorry for asking what may be a very basic question, but what is the procedure to check/set the ignition timing on the S?

Thanks-

Lynn