Jonny Retrofit

Good to know, thanks for reporting back.

Repeat the test with your meter at the green wire connector. Then, at the connector on the side of the distributor. You should get the same ohm reading as you a measuring across the sensor in the distributor. Narrow it down. My money would still be on the wiring ‘upstream’. The wiring goes through the 14 way plug on the back of the relay panel. Check and clean contacts. You can splay the pins out a bit for better contact.

Correct, the locking collar is only for the SC and Turbo distributors. Locking an earlier distributor is fairly easy. If you remove the vacuum unit, points, side clips and the 'spade' connector, you can pull out the internals to reveal the weights. I am not sure if all units are the same but on the early ones, there is a rectangular steel plate with the weights beneath. Put the unit in a vice, to stop the gear rotating and turn the centre shaft and watch the weight move. You want to lock the weights so they are fully out. best way is to drill and tap an M4 hole in the steel pla

@gtgrad Good job!

@Mothy yes, this has come up in discussions a few times. I think the issue might be 'tuning' the knock sensor to the 911 engine and finding a suitable place to install the sensor without having to drill the heads to carry the 964 system. The knock sensor itself does not provide a simple knock / no knock signal. There is electronics involved for the signal conditioning and setting up to the cylinder size etc.

Green LED on top of CDI+ unit should: 1) light up bright for 1 second when ignition turned on 2) flash when cranking.

Next test is remove coil king lead, insert spare spark plug directly into coil top. Ground plug thread with a clip or a jump lead to ground. Crank. Spark?

Tacho sweep on ignition is good - a feature. What coil are you running? And what is the resistance across the two terminals (ignition off, box disconnected)?

@gtgrad CDI 6 pin connections are as follows looking at the PLUG** on the harness with it's two keyway 'ears' at the top A top left: COIL 'A' 15 top middle: 12V 7 top right: Distributor Signal + 31/1 bottom left: COIL '1' (-) TD bottom middle: Tacho Drive 31d bottom right: Distributor Signal - **Note: The sticker on the side of the CDI case shows the CDI SOCKET connections on the unit as you look into the connector. Basic checks CDI box disconnected. At CDI plug on loom with ignition OFF: Check resistance between pins 7 and 31d. Sh

Looks that way if you have a JB distributor but check the spec sheet.

General Info: 3 Pin. Designed for use with 'points'. Used on all road going 911 cars from '69 up to and including Carrera 3.0 6 Pin. Uses a 'variable reluctor' (VR) pickup, sometimes referred to as a 'magnetic pickup'. Fitted to all Turbo cars and SC. 8 Pin boxes are also VR. 3 and 6 Pin units are NOT interchangeable as the input circuit is different. Twin plug: It depends on distributor choice. Most of the aftermarket twin plug distributors (including the JB Racing one) use a VR pickup - the actual pickup sensor part is usually made by MSD or Mallory. So in t

HI Chris, Tachos on these cars are quite sensitive to battery voltage. It should not be less than 12v or more than 15v. If it is outside this range, investigate the alternator or the voltage regulator (external unit on some early cars). With a twin plug setup, you have two independent ignition systems and the car will quite happily run on one. Therefore the chances of both systems failing at the same time are very small, unless the items that are common to both are at fault, these being: 1) The 12V supply . Check for a solid 12V at both CDI+ units. 2) Ground. Pins 31/

The blower system and Porsche wiring is low side switching. As you look at the front of our blower unit, top left is 12V. The other three pins are ground for each speed. From memory, the bottom right is the high speed ground. You could use a variable motor speed controller. It would need to be rated at 15A continuous. Generally speaking, variable speed control was avoided in automotive because of the large amount heat that needs to be ‘lost’ at low speeds. Traditional 3 speed resistor packs get round this problem by using the fan air to cool the resistors.

The blower in our system is designed to be controlled with the original fan slider from the fresh air system. All LWB cars (‘68-) have these controls. This is part of the original car’s wiring so does not connect to our ECU. If you want to delete the slider panel completely, you will still need a fan speed switch of some kind. You would also need a way to ‘steer’ to the screen and feet provided by the other slider levers. If you are happy to use one fan speed only, you could use the grey contact relay wire to activate a relay to switch the blower fan on. That would then tur

Glad you found the updated wiring diagram. On the 964/993, the temperature is regulated by the CCU, blending in hot air from the heat exchangers. The CCU only commands the AC compressor on and off. Installing our system without the temperature sensors, temperature control from the CCU will work in the same way. The system will function in what we call Hi/Lo mode, running at high power unless the battery voltage falls in which case it will run at low power. Most customers are fitting the high output alternator so the system is unlikely to go to low power. In the Climate mode, t