Noticed recently that my 86 951, when slowing down in 3rd, 4th, 5th gears.. slightly bucks... or chugs upon this deceleration. Very slight, but annoying, like passengers noticed.

Sort of weird, didn't do this before.

There was some adjustment recently to the TPS switch and a new throttle cable. Could that cause this? But I've triple checked and all seems to be adjusted properly (both the cable and the TPS switch)

B

 

You're on the right track with the throttle switch, position sensor, throttle cable. There's supposed to be no fuel on decel above 2000RPM, so if the switch comes off the idle setting intermittently, you'll get less than smooth decel. Make sure the throttle cable isn't so tight that it's pulling it off idle accidentally.