View Single Post
SFE SFE is offline
Registered
 
Join Date: Nov 2022
Posts: 35
MFI engine stalls at idle when RPM transducer is engaged

Hi all,

Here is the problem...

Car is a 1969 911E (2.0 liters with MFI) which was completely rebuild.




The only thing that was not working was the RPM Transducer (also called the Speed switch I guess).

So I bought a new one :



When I test the transducer it's ok : I put 3000 rpm, press the microswitch and the rpm oscillate between 1300 and 1600.

When I stay at idle, after a few seconds 12V is intermittently sent to the shut off solenoid and the engine end up stalling (the solenoid should not be energized below 1300 rpm and my idle is a solid 900 rpm one).

Here is a video of what happens :

https://youtube.com/shorts/lgupWjk-Fgo

With some folks on the Early 911s registry forum we checked all the wiring and everything seems OK.

Any idea ?

Last edited by SFE; 09-06-2023 at 09:18 AM..
Old 09-06-2023, 08:24 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)