boca928s

my 1985 928s while in park and you hit the gas pedal it feels normal... gets high in rpm range but when driving the pedal seems much stiffer... very hard to get the car to open up, doesn't seem like it kicks down to lower gear, performance very poor... could it be related to throttle cable or more the transmission itself? it bangs hard going into 2nd and 3rd gear... gear indicator light only works lit up in d and 3 I never see it lit in 2 when i move the gear selector all the way down..... I am thinking I need tranny rebuilt...?

Adamant1971

Check the Bowden cable for proper adjustment per the WSM.

boca928s

thanks

Geo55

Hard shifts? How is your modulator valve and pressures? Sounds like you have some blown bulbs in you selector.

boca928s

my 2 never lights up... all other bulbs light up... car does not shift well.... either needs a major adjustment or rebuild.... very hard to get the car to drop down a gear even when smashing the gas pedal... if I downshift manually and I hold it in gear over 4500 rpm the car comes to life, if in drive the car drives like a yugo

jetrainor

This is likely completely irrelevant but.......i changed out the blue/black valve which snaps into the brake vacume booster and two lines come off a splitter, one of mine had been disconnected.....i dont think it is my imagination when i say i noticed a livelier pedal response.....seemed freer revving.......for what it's worth.

Landseer

Sluggish, early shift, slam shift sounds like vac leak. In 85 it will cause also timing issue that further inhibits pickup by not activating the map sensor within the engine controller at passenger footwell.

should be 2 kickkdowns, first with Bowden cable at say 2/3 throttle, second when pedal approaches floor. The floor adjustment is made with a turnbuckle link beneath pedal. That vac actuation of timing is why there is a little vac line attached to controller on 85/6.

Am not understanding pedal resistance when in gear though.

The very first thing that I normally do with 85 is adjust throttle linkage. Adjustment is at firewall, do a search here to find exact procedure. You are listening for click of TPS coming on/off idle position during this process.

Second, adjusting Bowden aka kickdown cable is also a huge initial part of waking up the car. Frankly, though I led off with comments about vaccum, this cable adjustment is most typically where most impactful improvement happens.

So adjust throttle cable, adjust bowden, adjust gas pedal turnbuckle, do a vac check at computer....

Also, do not apply a vac tester to the computer itself. Leave that be. I did and broke the internal diagram inside the map sensor that is soldered to the board. That was a major FUp. Once that happens it is so sluggish sub 3000 that you can barely drive it in traffic.

WALTSTAR

Exactly why I drive a manual..

boca928s

thanks I am not a mechanic, so I will need to have all that looked at by one...

GregBBRD

Yeah, those early dual disc clutches and the synchros/sliders never seem to have problems.

MFranke

If you adjusted any of the throttle linkage cables recently, be careful that first off, the accelerator cable and Bowden allow full range of the throttle cable (make sure you aren't overly tight on the transmission cable or the pedal cable). Then adjust the bowden (transmission) cable so that the cup lines up and goes over the ball without any pulling. Misadjustment of these can adversely affect your performance, shifts and pedal feel.