hello,
On a diagram of the CU and injection AMPLI I see 2 wires (From CU pin 4 and 5) gooing to the AMPLI (pin 11 and 12) for 4 injectorgroups of 3 injectors each.
Theoretically one could drive 4 groups with 2 wires if it was binary but I guess this system is not digital yet.
Any one can explain? Thanks!!
PS. My diagram has also a EGR-CU but there is no EGR in European versions of this car.

 

The D Jetronic is Analogue, you are correct.

Its been 25 years since I rewired the XJ12 S2, and somewhere in teh shed will be my scribblings.

I will look tomorrow and report back, but I have a very dull bell indicating that I grouped them the same as the HE, which is the P Digital system.

As in 4 groups of 3.

1, 3, 5A
2, 4, 6A
1, 3, 5B
2, 4, 6B

Not sure if I used one or two power wires, that will be in the scribbles.

 

OK, Found it.

I have rewritten it into Word, so we can all read my otherwise terrible hadwriting, and shorthand.

Need some more, ASK.

D Jetronic Injector wiring from the amp.doc

 

Slick. Not that I need it or even expect to need it in the foreseeable future, I had to look. This machine is loaded with Libraoffice, a Word knock off. It handled it well.


OTH, I'm getting the weird idea that my 94 Jeep Grand Cherokee with the I6, just might use a version of Jetronic!!!! Gotta have look somewhere. So, far over it's 215 K miles it has performed with out a hitch. Well, two. Battery and starter replaced.


Carl

 

Hello, Many thanks.
If I read it well: KB is delivering the +.
KU and KG als pulses for the transistors delivering the Minus. So, in one cycle of 720°, CYL 2A 4A 6A AND 1B3B5B are injected at the same moment by means of the KU line, the others (depending of KG-line) 360° after that first one.

 

Memory now, so pleasae dont quote me.

Waaaaaay back, I did a Bosch Training course, that included the D Jetronic system, as used on DS21 Citroen, for the sake of the course.

They had a dual contact point trigger cassette that slid into the distributor, below the Ignition Contact plate. Those trigger points were opposite each other (180deg) on that cassette plate, and operated the EFI system, just as our Trigger Board does.

Now the dull bit takes over.

The 2 contact points were NOT opened at the same time, there was only ONE lobe on the shaft related to those points, again, like our single magnet in the rotor heel.

So one set of points fired the injectors realated to them, and the 2nd set fire the others. Now that car was only a 4 cylinder, but the sequencing was the same.

Ours fires exactly as you say, then the rest at 180deg distributor rotation which =360deg of the engine rotation.

That is another reason the original 3 wire trigger board was updated to the later 4 wire unit. The early Reed switches were crap at best, and the later Hall Effect sensors were bullet proof.

 

Thanks Francis for digging into yr mem!

 

Hi Patpin,

Since you deal with XJ12, would you know where could I buy the injection wiring for a 1996 ? Thx !

 

1996 would be a 6ltr.

I reckon you will joining all of us 5.3 owners, and making your own, ONE wire at a time.

I am NOT familiar with the 6ltr set up, having only seen 1 car waaaay back when it was on our showroom, so fiddling with it was not permitted.