Another oddity with Jaguar; The 7" of vacuum at idle noted by your distributor, may not be true manifold pressure, but throttle body vacuum. At idle the distributor is getting throttle body vacuum signal; with a little throttle and a slight delay, a valve under the intake manifold switches the distributor vacuum source from throttle body to manifold vacuum. UK cars used manifold Vacuum exclusively.
Rgds
David

 

So, the fuel injection on a Series 3 is D Jetronic, isn't it? If so, I may have the wrong distributor.

 

https://www.jagweb.com/aj6eng/42efi/index.php

 

So, when I reached out originally, 123 told me that this distributor (Tune+) would fit my car. I think they misunderstood my question. Now, they are telling me that I would need the Tune+ 6-R-V-G-IE for a D Jetronic fuel injection. I'm not sure of the difference between D Jetronic and L Jetronic.

 

I sent them an inquiry and this was the response.

Monday, March 25th, 2024 at 4:18 AM
To: info@123ignition.de
Dear Sir:
I have 1984 XJ6 S3 (EFI) jaguar with 8.1 CR and recommended fuel of 87 octane (US)
What programable distributor do you have that is recommended ?
What is the initial static advance setting? and
What is lowest ohm coil value do you recommend?
Thank you.
David



Hello,
pls have a look here:
distributor: https://www.123ignition.de/123-ignit...bluetooth.aspx
coil, select 1.5 Ohm, oil filling: https://www.123ignition.de/123-ignit...-ignition.aspx
wire cable: https://www.123ignition.de/123-ignit...aguar-xj6.aspx
for the advance setting we probably have ignition data we can program before dispatch
Kind regards
Anke Verheyen
+49(2452)9574663
+49(2452)9574668

I looked for this on their web-site and could not find?? "Tune+ 6-R-V-G-IE "
Rgds
David
PS: I think the AJ6 write-up confirms that you have L not D Jetronic fuel injection.
https://123ignition.com/product/tune-6-r-v-g/ ???

 

Based on the signature block, those a re the folks I reached out to originally. They made the same recommendation.

THe pictures are of the chat I had in the past couple of days....

 

1

 

David,

You gave me another idea.... I put a "T" in the vacuum line to the brake booster and then attached it to the distributor. I temporarily plugged the other vacuum line I took off the distributor. Fired it up, and sure enough, the vacuum is now reading -13 inHG at idle!

However, now it seems that my alternator is failing. This is a new issue. Every time I start the car, it is slow to wake, and I have to rev the engine a few times to get it to start charging. I can't help but think this may also be related. I ordered a new one and will be installing it this weekend. Maybe after that I will have some more news.

****UPDATE****

I had replaced the lights on the dash with LEDs last week. For some convoluted reason, you can't change the ignition warning light with an LED or the alternator won't wake on start up. This is one of the craziest things I think I have discovered about Jags so far! So I went out and replaced the light with an incandescent light and now the alternator is working again, and the idle is smoother! Going to test it again tomorrow. SMH, a light bulb! Who'd a thunk it?!

 

Good find. What RPM are you getting at 13" vacuum ??
I think you need to look for the other 5" of manifold Vacuum... 13"+ 5" = 18". All the symptoms you have listed point to a vacuum leak: hard start, lumpy idle, but seeming to be ok at higher RPMs!!! At the higher RPM, the excess air from the leak causes excess oxygen at O2 sensor, O2 sensor tells the ECU to add more fuel until the leak is neutralized. At idle, you have mechanical mixture ratio (AFM), only modified by CTS communications with ECU as to coolant temperature.

While you are waiting for more input from 123 and new Alternator; get yourself a Nice Cigar. Pull the hose of the manifold brake booster nipple. Put new line on nipple, light the Cigar, and blow smoke into manifold until you see it escaping somewhere!!!
At least you will be able to enjoy a Fine Cigar while potentially eliminating one more issue. (yes have your Fire Extinguisher close by)
Rgds
David
PS: Agreed, you have to be careful with upgrades??....."So I went out and replaced the light with an incandescent light and now the alternator is working again"

 

So, I noticed that the vacuum line came off of the cruise control and was just dangling. I reconnected it. I now have -17" to -18"Hg at 850-900 at the distributor.

Still is not idling smoothly. I am going to put a battery charger on it, then let the car run for a little bit to see if it smoothes out any. Again I appreciate all the help!!

 

Perfectly understandable, actually!

The "excite" circuit of the alternator needs xxx-resistance to function. It was/is standard procedure for many cars for the warning light bulb give the required resistance. The LED bulb does not provide enough resistance to do the job.

If the excite circuit doesn't work the alternator won't work, or won't work until a higher RPM is reached

But there's something not so understandable.....

In the warning lamp cluster Jaguar included a resistor for the alternator warning light. Presumably so the charging system would work if the bulb failed. If my presumption is correct then your resistor is on the blink. Not that I'd worry much, mind you. Your charging system is now working.

Cheers
DD

 

Glad to hear you have good manifold Vacuum.
I think you mentioned you installed new spark plugs a few months back. Most automotive parts web-sites will show resistance plugs as OEM recommendation. This was for Radio Interference; with modern resistance spark plug wires, this is not required, and waste some of the spark energy.
These are the Plugs I would recommend to get best idle.
6 x Spark Plugs Made in Japan NGK V-Power 7327 BP5EY ( on E-Bay)
Rgds
David

 

Pulled these today. The before and after pictures are about a week apart. I'd say, she is running a little rich!!


After

After

Before

Before

 

This morning, I put in a fresh set of spark plugs, then I pulled the new cold start injector and replaced it with my old one. I can't get past the feeling that the new cold start injector was leaking. Once done, I fired it up. It was the most buttery smooth idle I have ever felt in this car. It was almost as smooth as my V-12!! I took it on a little drive and then came back home. I started it again. Both times, it fired right up with no hesitation. I'm going to give it a few minutes and then try again. Recently it had started out running better when I first started it for the day, then ran badly after it got warm. I just want to make sure that doesn't happen again.

 

Guys, I think we can now put this into the "Resolved" column!! Thanks again for everyones' help and input!!

 

Let us know when you are 100% satisfied with 123 setup and the technical support.
Many potential issues eliminated one (or two) at a time until the car runs as designed. Well done and documented for others to learn from.
Rgds
David

 

Will do. I had another unrelated item to fix before putting the Jag back out on the street. I'll report back in a day or two with how 123 Ignition is working. I'll upload my map curve too. Hopefully, that will help someone else set up theirs, too! Thanks again!

 

So, it has been about a week now. My XJ6 is still running great. All the issues I had before (at the beginning of this thread) have been resolved. I used the 123 Ignition distributor, 123 1.5 ohm matching coil, and Pertronix 8mm spark plug wires. I bought a smoke machine on Amazon for $75 and eliminated all vacuum leaks. I have heard others say that their car was like a completely different car after the upgrade. I would say that is a very good/accurate description! I would NOT recommend www.123ignition.de as a source to buy the ignition system. I found them to be very rude and difficult to work with. At one point I had to file a dispute with my credit card company because they charged me, I didn't receive anything, and they refused to respond to my emails. That site is a reseller of the 123 system and there are others that I am sure would be much better to buy from. I am attaching my map curves below. Hopefully, this will help someone else. Thanks everyone who provided help and feedback! I cannot express how much I appreciate it!!

 

Great news on the results, the well documented process will help others.. I not sure I would have passed up a $12 Cuban cigar, for the $75 Amazon Smoke Machine, but then again, you may have occasion to check for vacuum leaks in the future.
Rgds
David

 

After watching you tube on XJ6 S2 distributor upgrade to 123 blue tune. I still feel the math is a little left handed??
See if this work sheet is how you understand the Math from vacuum to absolute "kPa abs"
Thanks
David