Well, I think I have the "dreaded" dead or dying distributor amplifier issue.

Symptom:

Running fine then just dies. Period. Then no successful restarting. Almost catches (receiving fuel) and dies. This lasts for about 5-10 minutes.

Lastest:

After storage for 5 months ( I just purchased the car in November) The car started just fine. I pulled it outside and it idled for about 10 to 15 minutes warming up while I wiped it down, etc. I was about to take it for a short drive and when I hit the lock button by accident the car immediately died. ( I think this was just a coincidence or slight current draw triggered something but I digress). The aforementioned issue occurred. After 5 -10 minutes it started and I decided to take a chance and pull out of the driveway after 5 minutes. It died again before the end of the driveway.

A repeat of the above with the exception that I pulled into the garage as it was getting dark.


The first time:

This very symptom occurred when I first picked up the car in Maryland last year. I heard a "clack" in the interior someplace (but now I think its a ventilation flap, etc) but at the time thought maybe it was the fuel inertia switch.
When I was leaving the place of purchase after a test drive, check transfer the car shut down as described above! JUST before a 600-mile trip.

Well, I made it home pretty uneventfully but the car did lose power while in gear once or twice very briefly so I knew something was up.

Over the winter it sat enclosed and I just placed a new fuel inertia switch just in case.

Conclusion:

The symptoms described reminds me of the 1977 TR7 I had that was my first car and the bloody thing died on me in a similar fashion (once right in the middle of traffic). I believe it was the distributor amplifier and it was replaced with an electronic replacement. I can't recall what it was as this was many years.
ago.

That said I'm suspecting this may be the case. I have a 1978 XJ6L with FI. I have to check the distributor style to see of the amplifier is integrated or separate (as per Pertronix description for part numbers) and the coil could be original as it looks like it has the same patina as the rest of the motor compartment.

Does anyone here have the S2 from this era and changed to a Petronix or similar?

Any other ideas on what may cause the symptoms above which may be indicative of the era and brand of car?

 

Gotta get the specie identifies. The TR7, Pertronix and your car are different.

Check the inside of your distributor No points and condenser. No pertronix box or similar. But, follow the wires from the distributor back. On the intake, you will find a tin box. Inside is the GM/Delco amplifier..

It as a lot of other electronic devices fail under heated condition. It can be tested, cold or warm on the bench or in situ. I'll leave it to others more familiar with this systemn to guide you.

What I can do is to suggest that you carefuly check the wires and connectors for cleanliness and soundness.

Jaguar mantra, good elsewhere.. Clean,. tighten and lubricate.

Carll

 

Thank you, Carl, for the response.

However, I'm aware the systems are different. I was just describing the symptoms were similar.

I checked the outer visuals for the distributor and I noted a blue cap with SCREW down attachment and not the twin band release the specific era distributor should have. A quick search appears the dealership the OP took the car year after year replaced it with a later '82-'87 style. Which I find odd since they would have had to change the drive.

That said the proper distributor for a '78-'79 model is I believe a 45DE6 with the band clamps and a much different appearing cap (in black).

I'll have to check by pulling it out this weekend to confirm and take your advice and check all leads and the amplifier unit.

 

Thank you, Carl, for the response.

However, I'm aware the systems are different. I was just describing the symptoms were similar.

I checked the outer visuals for the distributor and I noted a blue cap with SCREW down attachment and not the twin band release the specific era distributor should have. A quick search appears the dealership the OP took the car year after year replaced it with a later '82-'87 style. Which I find odd since they would have had to change the drive.

That said the proper distributor for a '78-'79 model is I believe a 45DE6 with the band clamps and a much different appearing cap (in black).

I'll have to check by pulling it out this weekend to confirm and take your advice and check all leads and the amplifier unit.

 

Well, I checked the system again and found the issue I believe. The usual "fix" is not applicable here and the PO had the dealer (or more accurately the dealer decided to install a different distributor from a later car and an "InterMotive" computer control module 15955. Of course, I don't think it could be placed in a worse spot. Next to the distributor (about between 6 - 8 inches away and under the intake manifold bolted to a brace which is attached to the motor, etc. And of note to add to the annoyance I started it now the tachometer does not work.

I looked up InterMotive and indeed they provide programmable units, etc. I could not find this number though.

See images below. I highly doubt anyone here on the forum has this set up and thus could not really offer any support other than replacing the unit.

InterMotive control Module. A aftermarket solution the dealer came up with for the PO. Located a few inches from the distributor.

A different distributor with the screw retention style rather than the twin clamp. '82-87 Vanden Plas FT58K9 45DM6

Now I'm sure IF I could find this unit or replace with a suitable replacement. I'm sure it'll cost more than the route I'm taking.

That route goes back to the original distributor first of all. I ironically found a NOS unit 45DE6 for my year XJ6 '78-79. And for $165.00 no less free shipping and NEW. From there I can install a Petroninix and bypass the fail prone distributor amplifier.

To recap, I don't have the "AC Delco amplifier" on the intake manifold and the '78-79 cars with FI had the piggyback style of the distributor.

So are there any comments on what else I may need? Besides timing set as close as possible before the start-up of the new distributor and TDC or BDC on 6cyl? And of course, following the wiring.

I want to start the car with the NOS distributor and then move on and install the Petronix unit for the 45DE6, new coil and I may as well throw in new plugs.

And lastly does anyone here with the internal amplifier know if the unit can be replaced with something simple like the AC Delco.

Thanks in advance!!


-C

 

C

There is probably more info than you want at post Jaguar XJ6 S3 Ignition System Repairs:

So I summarize , I would not go back to the old NOS distributor, the 45DM6 is a better unit if healthy.
Look at inside of Distributor cap and rotor, if looks ok move on to Amplifier.

Without trouble shooting, the odds are the GM 4 pin module inside the amplifier on the front of the intake manifold is the issue. Remove amp 2 attach bolts and remove back plate 4 screws and you see the 4 pin GM module. Your local auto store should have a AC D1906 module or can get it in a day. It will come with new heat sink paste, make sure you get all the old heat sink material out with Acetone. Once installed put it all back together and see if you problem comes back.

If it comes back, leads to pickup in distributor could have a break. wiggle wires and connectors looking for loose or poor connections; check all this with multi-meter.

Finally the coil itself can fail when warm... I had this on a coil less than one year old, and it drove me crazy, as it always worked when I tried to sort it out. Finally a Tech at XKs unlimited had it occur when it was in shop. You need to have the coil that matches the 45DM6 distributor, not the old one. Coil P/N LU-BD198: 40,000 Volt 0.8 Ohms Coilor equivalent.

This trail you are on, has been traveled many times with XJ6 S3 owners.

If you want to just skip to new distributor without trying to fix your current setup, you will see toward the end of the XJ6 S3 System Repairs Posts comments, Jaguar owners have successfully installed Pertronix distributors,with matching coil. This eliminates the Amplifier, but you must plug the holes (shorter bolts) where the amplifier is mounted on the intake manifold or you will have a massive intake air leak. Pertronix D171618 is a high performance unit, that is plug and play with a matching coil that has Jaguar fans.

Intermittent heat related failures are tough and expensive, if you have car in the shop all the time, most of this is easy to do yourself. Good Luck

Rgds David

 

David,

THANK YOU very much for your detailed response and taking the time to do so! I much appreciate it!

The link provided is NEVER enough information! lol I keep in mind if I decide to go the route of the OE NOS distributor.

With your comments/suggestions, I'll check on my set up today. The one element you did not mention was the inclusion of the InterMotive unit.

I'll search for the amplifier on the intake manifold and see if it's even connected. The issue is the InterMotive module role in all of this. Is it now the amplifier, etc? I see the two wires leading from the distributor directly to it. So I'll see what is exiting from it.

I'll also check on the distributor as suggested. I'd rather stay with the set up for now if I can find the fault "easy enough".

One last comment made is also of interest. The coil. It appears the original coil is still in place judging by the "patina". If this is the case when I arrive home to check it this means the coil was never replaced to reflect the distributor change.

The mystery continues...


-C

 

JAGUAR XJ SERIES 15955 Ignition Module by INTERMOTOR

C

This is an aftermarket amplifier matched to the 45DM6 distributor. If you open it up you will find inside the 4 pin GM style module that is suspect. This I would changed to the AC D1906 Module



So at this point it is 50-50 whether it is the 4 pin module inside the amplifier or the ignition coil that is the culprit. Your favorite auto store should have a AC Delco, Bosch or Lucas ignition coil that will be fine. Request a ignition coil for a 1984 XJ6 4.2L engine Jaguar. (this will match your distributor). If they have several choices between 1.0 -1.5 ohm, a 1.0 ohm will have a hotter spark. The coil is easier to change in this process of elimination and is approximately same cost as module.

Added note: Your picture of the amplifier does not show how it is mounted. On the 84 XJ6 it is mounted on the front of Fuel Injected intake manifold (Blue Arrow), which acts as a Huge Heat Sink and electrical ground. Since the the most common failure is overheating, the mounting with a large heat sink is critical. Also the amplifier case needs to be well grounded; an additional 14 gauge ground wire from a ring connector under one of the two mounting bolts to a know good ground on the car is important.






Rgds
David

 

Once again David...Thank You!

And also kudos to the internet search! I did the same and could not find the bloody InterMotive unit as accurately as you have.

I did pull the cap and it all appears fine with little wear. Actually, the cap and rotor appear new.

I ran out of time so the Intermotive unit will come out today. I'm glad you pretty much answered my question and thoughts regarding the location of the unit. It is mounted right next to the distributor (about 5"-8" away on a 10" -12" "stalk" that has one mount point at the base. It's attached low on this "stalk" with one bolt. The "stalk" angles upward under the manifold (springboarding) and the unit is mounted to it by 2 13mm bolts.

Judging by your comment regarding the heat and vibration issue, (which I was thinking as well) the placement of the unit is not helping things. First NVH. I'm guessing the "stalk" vibrates since it only has one mounting point and it's NOT on the motor with metal to metal contact between the "stalk" and chassis or subframe, etc. I suspect heat wise it's not a great situation either. In any case, it's safe to say the "stalk" is not a great heatsink. The grounding of one of the mount bolts seems to be non-existent...UNLESS The green wire in the image is a ground (which IS grounded on the top end) that is attached to the back of the upper mount bolt with a nut and washer. I shall find out today.

It may be mounted there due to the length of the wires from the distributor and they (the dealership) mounted it where it is due to this aspect of physicality rather than mount the unit higher on the intake manifold thus needing to lengthen the distributor wires (unless there is a drawback to doing this). And this IF they need to be lengthened. I will have to see when I relocate the unit to the manifold. That is IF I can mount the unit there. This is, after all, a series 2 car and a suitable mount place may not exist like the series 3 cars. The series 2 cars had the 45DE6 with the piggyback amplifier so I doubt the manifold would have a spot for an amplifier unless Leyland knew the future... lol But you never know.

However, upon reflection, this is probably why the dealership installed the springboard "stalk" thing.

I'll pull the Intermotive unit out today and open it and replace the module. The coil suggestion is a go as well. I may as well and while I'm at it replace the aged ignition cables. And clean up the rather suspect wire routing.

Once again, thank you very much!

- Chris


PS. I'm attaching the earlier image of the Intermotive unit. The number 15955 is spot on to your example. The location I hope you can see make out by my description. The intake manifold is seen upper left corner of the image and the distributor is located lower right of the image.


The interMotive unit. Note the intake manifold directly above and to the left. The distributor is lower right with blue cap.

 

Chris
Can you take a picture of the stalk once the amplifier is removed. if it is robust enough, you may get away with a 4 x 4 x 1/8 aluminum plate(heat sink) between amplifier and stalk.??
Rgds
David

 

Will do...

 

Chris

See this E-bay listing for heat-sinks that can go on cover of Amplifier right over module inside. I did this with my 3.8S retrofit of XJ6 S3 distributor and amplifier system. I used 1/8' thick aluminum 4" x 1" x 5" angle as heat-sink and mount (on RH engine mount bracket), plus putting self adhesive heat-sinks on cover.
Rgds
David

E-Bay listing: 4pcs 22x22x10mm Aluminum Heatsink with Blue Thermal Adhesive Heat Transfer Pad US $1.99 free shipping (2-3 weeks shipping, but can be added later.)

 

David,

I removed the "stalk" last night as well as the coil, etc. I'll attach images at the end of the saga. lol

Se, The "stalk" is utilizing one of the bolts for a lower mount. Once out the amplifier was easy as you can imagine removing. I also removed the coil but did not bother to take a photo as it's old enough to have what markings were on the body to wear away. It is a Lucas brand. I'm going to assume by its appearance it's as or near as old as the car.

I then opened the amplifier body and there lay the module. It came out no issue and whatever was used to "affix" it to the bottom plate was for not. Actually, the grey/white substance looked and felt more like some sort of graphite grease. Not quite slimly but not quite dry either.

I purchased a new module but of course, at first the auto parts staff had no idea what I was showing them and the usual question of "what year car" was asked. You can use your imagination where this lead. Once I steered them back on track to the AC D1906 which he found no such number as this particular series of stores (O'Rielly's) do not carry AC products. Nor does Autozone. BUT NAPA may.

Then, luckily he had an epiphany and said the part in the amplifier box looked like a GM internal distributor part. His coworker came over and with my mention of "GM" when I first started my need we started looking for 80's vintage GM vehicles after I mentioned to look for 1980-87 Jaguar XJ6 (of which we found an identical image of the amplifier for over $229.00...lol

Pay dirt popped up on the screen when a 1980 Monte Carlo was searched. Several examples of the module came up including the AC D1906. Yes, the one he could not find prior. However, this module was not in stock so I just went with one that they had in stock. Unless there's some big difference between them all other than the $20.00 price difference I'll use it.

Next, I'll replace the coil. I will go to S&G which is primarily an import shop and see what they have.

Of note, I did see a place for an amplifier on the intake manifold. At least I think it is. I can see a faint outline of something that was occupying this space and the studs line up with the holes of the current amplifier unit. However, the InterMotive one is too large to fit AND I don't see how anything could have fit there with the coil occupying the same space. Also, the wires are too short anyway from the distributor. So it appears the unit will go back on the "stalk" once I paint it and make it look pretty...lol I'll also take your advice on the heatsink and clean up the wiring.

Last, I see a white wire with blue spiral tracer was broken from the white rectangular connector that dangles near the coil. I have not done my research yet in the service manual but perhaps this is the tach trigger wire? It suddenly stopped working the last time I started it.

Again, thank you, David. Let's hope this will solve the issue. Well, this one anyway!

-Chris


"Stalk" supports the amplifier unit. Note hole at bottom that bolts to lower mount in car.

"Stalk" supports the amplifier unit. No heat sink.


There she is ....

The manifold mount plate for a past amplifier? ' note coil intrudes into the space also note the coil its self. Older to say the least.

 

Thank you, David,

I see what you mean now and will take a look at the auction!


-C

 

Whew, what an exercise !!!

In my view, too many paths to think out. And each involves a bunch of bucks.

1. Back to original. Sans Pertronix, at least for a while. One change at a time philosophy!!

2. Duplicate the SIII system. Fresh GM module.

3. Fix the "stalk" issue. I see 'zip" in heat transfer there. Even if it takes the solder gun to splice in longer wires. That "stalk" is just far topo inelegant for Jaguar!!!

4. Simplist. Leave as is. Preemptive strike. A new coil !!!

Other stuff. Swap the coil end for end. It seems "backwards" to me. That would clear space on that pad. A far better place for any module than the "ugh" stalk!!!

That loose wire is probably the tach!! Schematic ? Or just hook it up!! Caveat??? Fry the tach???

In the tune of Jerry Lee Lewis, "there is a whole lot of shaking going on"!!

Carl

 

Thanks, Carl for the input! David's suggestions have helped immensely. Actually, to be honest, the process has not been to intensive so far. I'd say I have literally 45 minutes into the job, not including the stop at the auto parts store...lol


Per your comments:

1. Back to original. Sans Pertronix, at least for a while. One change at a time philosophy!! I did buy a NOS new 45DE6. Just arrived Wednesday. After David's comment on perhaps sticking with the 45DM6 Series III retrofit by the dealer when the PO had the car. When investigating the change this was when I found the InterMotive module. At this time I would say stick with the 45DM6 in place and NOT moved (timing).

2. Duplicate the SIII system. Fresh GM module. Already in place by PO. Going this way already. Purchased new GM module last night.

3. Fix the "stalk" issue. I see 'zip" in heat transfer there. Even if it takes the solder gun to splice in longer wires. That "stalk" is just far too inelegant for Jaguar!!! I see the same issue with this Mickey Mouse "stalk" but the heatsink David suggested may work. I'd like to avoid lengthening the wires from the distributor but in any case, I would have to make sure the amplifier fits and coil or no coil the InterMotive unit DOES NOT FIT in the area provided. The stud spacing is fine but the overall body is 8-10mm too large. So there goes that idea. I also tried to switch around the coil 180 before making the above discovery. No matter the body extends into the area.

4. Simplist. Leave as is. Preemptive strike. A new coil !!! Well too late for that... lol But a new coil I'm buying today. It appears old enough to have Grand coils. Since it only takes about 5-10 minutes to swap this is no big deal.

Other stuff. Swap the coil end for end. It seems "backwards" to me. That would clear space on that pad. A far better place for any module than the "ugh" stalk!!! Yes... But see above. I agree regarding the "stalk". Again, I did reverse the coil and unless the thing is clamped at the very end with the rest of the coil hanging in space the pad is covered. And again, it doesn't matter as the Intermotive unit does not fit in the space provided. I'll end up painting the "stalk" and refitting it with a heat sink as David suggested. One does not see it anyways once in place. Maybe along the way, I'll think of something else. Aka an epiphany!

That loose wire is probably the tach!! Schematic ? Or just hook it up!! Caveat??? Fry the tach??? That's what I'm guessing but I have a schematic at home. I just didn't go over it yet as I was about to leave to head to the auto parts store. I'll take a look over the weekend and make sure as I'd rather not fry the tach!

One last note I may have a new NOS 45DE6 for sale if I don't place it back on eBay or just keep as a period spare.

Also, with sticking with the current set up the cost is not too bad. $30.00 for a new GM Module and $30-$40.00 for a new coil. Black paint and connectors. Already have. Ok, add the NOS 45DE6 for $165.00 but I have the option to sell it.

Thank you for your input!

-C

 

Chris
white wire with blue spiral tracer was broken from the white rectangular connector that dangles near the coil. I have not done my research yet in the service manual but perhaps this is the tach trigger wire? It suddenly stopped working the last time I started it.

1. Yes, this is trigger wire to the tach.

2. The stalk looks like it is ok, very low vibration frequency and should not effect the Amplifier. (better not to cut wires)

3. I am curious what static timing the dealer setup after converting to the 45DM6 distributor? 15-16 degrees static?? 15 + 20 = 35 degrees all in advance (Vacuum capped off). Did the dealer make an annotation to the decal on the hood as to new timing target?

S2-4.2 engine: Best I can tell, is that the 45DE6 has a 14-degree mechanical advance, 28 degrees at the crank, this plus book of 8 degree static gives an all-in number of 36 degrees advance, with vacuum capped off. (91-94 Octane fuel)

S3-4.2 engine: The 45DM6 has 10-degree mechanical advance... 20 at the crank, plus (early models) 14 degree static for all in 34 degree advance with vacuum capped off. 1984 California car: 17 degrees static for all in number of 37 degrees. (“Calif car” 8.4 CR with 87 Octane fuel)

If you look at comparable ignition coils, many sights will show LU-DLB102, or (DAC3001); you will have a better set up with the later LU-DLB198 (XKs unlimited stocks them, + on E-bay)

Sounds like you are making progress... mystery gone!!!

PS: If you keep the 45DE6 as a spare, you will want to get new vacuum advance unit from britishvacuumunit@isp.com, a 30 year old NOS vacuum advance rubber diaphragm will be dust. Talk with shop owner and tell him you are going to replace the NOS pickup with a pertronix ignitor II ( P/N 9LU-161) and he will insure you get correct Vacuum advance unit... it may not be the one specified by Jaguar in 1978. (the LU-DLB198 coil will work with this)

Rgds David

 

I'm finally able to respond regarding the status of the XJ after a busy weekend.




I have to say David was an excellent source of knowledge and clear concise direction of sorting out the "mysterious" ignition fault resulting in sudden shut off at the most inopportune times. i.e at the light in traffic.

I can confidently say the issue is gone! Replaced the module, cleaned painted the "stalk" bracket while making sure the ground(s) were intact.
Replaced the coil with a DBL198, rerouted some of the wiring and repaired the "suddenly" broken tach wire.

She came to life on the first crank! However, I waited and let it idle and warm up. The last time I did this as soon as I started off on a short drive the system shut down.

NOT this time! My historic/authentic plate registration had ironically JUST arrived so I took that as a sign and decided to take a longer drive.

NO issues and all seemed well indeed! Of course, I did knock on the IP a few times when things kept working! lol

Next, I think I'll replace the ignition wires. They look original or at least very, very old. Plugs as well.

The only "mystery" now is WHICH caused the issue. Module or coil? Well, at this point I don't think it matters. Who knows, the issue could have been a combination of both.

As for the timing degree aspect, I'll have to delve into that one and find out. The vacuum is attached so thank you for reminding me to cap it when checking. I could have easily neglected to do so.

In regards to the NOS 45DE6, I am on the fence to keep it or just resell on eBay. I appreciate the reminder regarding the diaphragm and the source for a new one. I may or may not at this point do the update. I'll see how I feel as I now tackle this next item(s) on my plate which the supercharger "front end mode" service on my 2003 R53 MINI. I really need to complete it as the weather is finally starting to turn.

Again, Thank You, David, for all of your assistance. I now hope I can assist someone else in this regard as I reacquaint myself with my "old" hobby on a larger scale.