Deceleration system for extra engine braking?
04-22-2017, 06:56 PM
#16
Burning Brakes
Thread Starter
Fixed
I finally got around to looking into this today. I purchased a microswitch from 928 Specialists some time back, and today removed the lower microswitch with the intent to replace it. I checked it on my ohmmeter first and it worked fine!
For what it's worth, mine was an adjustment/mechanical issue. It's now apparent that the switch was adjusted at the factory to BARELY engage with the throttle closed. And for some reason something changed over time and it wasn't engaging reliably every time. Btw there are elongated slots where the screws go through to allow the switch to be positioned closer or further away from the throttle mechanism and mine had been positioned all the way 'close' to the throttle mechanim. I almost suspect that the long external arm on the switch (mild steel?) slowly bent over many years. When I put the switch back on, I discovered all this because the switch would not properly engage - even at the closest setting -- so I very slightly bent the arm on the switch up and away from the switch, basically straightening it out.
The key point for future adjustment - just ensure the switch clicks as close as possible to the throttle at idle -- literally something like the last 1/64 of an inch or so! Any more than that and I think you'd notice having to step on the gas to kick the engine out of deceleration mode, as opposed to just barely touching the gas.
FWIW!!
Rick
For what it's worth, mine was an adjustment/mechanical issue. It's now apparent that the switch was adjusted at the factory to BARELY engage with the throttle closed. And for some reason something changed over time and it wasn't engaging reliably every time. Btw there are elongated slots where the screws go through to allow the switch to be positioned closer or further away from the throttle mechanism and mine had been positioned all the way 'close' to the throttle mechanim. I almost suspect that the long external arm on the switch (mild steel?) slowly bent over many years. When I put the switch back on, I discovered all this because the switch would not properly engage - even at the closest setting -- so I very slightly bent the arm on the switch up and away from the switch, basically straightening it out.
The key point for future adjustment - just ensure the switch clicks as close as possible to the throttle at idle -- literally something like the last 1/64 of an inch or so! Any more than that and I think you'd notice having to step on the gas to kick the engine out of deceleration mode, as opposed to just barely touching the gas.
FWIW!!
Rick
04-22-2017, 07:08 PM
#17
Burning Brakes
Thread Starter
Oh one more word to the wise... The screws securing the microswitch thread not into the mounting plate but instead into a small separate little backing plate. Watch out that the backing plate doesn't fall into the valley... Mine did and I was lucky to be able to fish it back without having to disassemble the intake!!
