Philip Lochner 1980 Jaguar XJS V12 5.3L (10:1 CR)

Philip Lochner
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Philip Lochner 1980 Jaguar XJS V12 5.3L (10:1 CR)

Post by Philip Lochner » Sat Jun 24, 2006 7:24 am

Last update: 13 Aug 2009

My Other MS projects::
Jaguar E-type V12 : viewtopic.php?f=92&t=22941
Cobra V12: viewtopic.php?f=92&t=22908
Land Rover V8 4.6 : viewtopic.php?t=17941
Land Rover V8 3.9 : viewtopic.php?t=22468

I have a PDF file attached with the same pics of the links to - BUT you need to be subscribed to MSRUNS to see these attachments.

Vehicle: 1980 Jaguar XJS Pic: ( ... 1155725717 )
Engine: 5.3L V12 (Pre-HE = flat head) 10:1 CR Mechanically standard
Gearbox: 5sp Tremec manual purchased from Keisler Engineering.
Injection: Port injection (12 x low impedance injectors) - 2squirts / simultaneous
Spark: Dual EDIS-6 systems with blue 8mm Magnecor HT leads
ECU: MS-2/Extra 2.1.0d on V3 board with continuous Baro, dual WBOs controlling spark and fuel, built to control 2 stage NOS (not yet installed)
Comment: I would never have gone out to buy this car. It came to me in 03(family). Now that I had it, I had to get it to a useable state. Its taken me 4 years.... and in this time it has forced me to "master" fuel injection and ignition timing (compliments of MS)

Summary (for those not interested in reading the chronological reports further below):

MS Controls fuelling via the stock Low Impedance injectors using PWM (no current limit resistors) with the left bank on inj_1 circuit and the right bank on inj_2 circuit. For a road going engine it is highly beneficial to use an ECU (like MS of course ) that does NOT rely on current limit resistors to control low impedance injectors in a batch fired application. This because such resistors will INcrease the DIFFERENCE in opening times between injectors which can result in highly different AFRs between the different cylinders particularly when short injectors pulses are being called for (idle and partial throttle). This will manifest itself primarily when trying to lean out the AFRs at partial throttle. For race applications using current limit resistors is fine.

Initially I tuned the car on one VE (fuelling) table but found large AFR differences at low rpms between the two banks. She now runs dual VE tables where each bank is fuelled according to its own fuelling map with very similar AFRs resulting from being able to adujst each bank individually. I installed additional wires for the PWM flyback currents directly from the V3 board to the 12V injector wires as a precautionary measure having seen some guys having problems not doing so.

The OEM ECU (and my other MS/V3/B&G 2.687) injects 2 squirts/alternating per engine cycle. I'm now squirting 3 squirts/simultaneous. I found the engine to have noticeably more torque at low rpms, and engine response is most certainly more snappy - with less AE enrichments. Even the engine sound changed when I converted to 3/sim with it now sounding more like a V12!!

Ignition (Dual EDIS-6 wasted spark) Pic: ... 1175449785

Each bank has the firing order of a straight 6. For this reason I decided to try using two EDIS-6 systems with each system doing ignition for one bank. Wiring diagram at the bottom of this post (download.php?id=5721) After testing the concept on the bench I implemented it on the car.

This was quite a challenge as it requires mounting a 36-1 trigger wheel on the pulley as well as two VR sensors 60 degs apart. I converted the mechanical fan to electrical in order to make room for these VR sensors and mounted the trigger wheel where the front-most groove of the crank pulley used to be (no longer needed for the mechanical fan.

The EDIS-6 modules are mounted in a coil pack assembly ( ... 1170846543 ) in a double-decker kind of assembly which I fabricated from 3mm mild steel sheeting. This same assembly may not work on the HE engines as their plugs are tilted towards the centre of the V making that area narrower. Although the EDIS modules are sitting deep in the V (rather hot) underneath the coil packs, so far they have not missed a beat. I am running 83degC thermostats due to our hot climate. Rather than using two EDIS-6 coil packs (6 post) I have used 3 EDIS-4/8 coil packs (4-post) in order to have all the LH bank HT leads sit on the left and the RH HT leads on the right for neatness.

Although the concept tested fine on the bench, something was clearly not right requiring an additional piece of electronics called the "SAW module" ( ... 1177496359 ) to change (delay) the SAW advance signal coming from MS so that it would be suitable for the B-bank EDIS module. (more detail below). I found that using spark plugs with internal resistors were imperative (before installing Magnecor HT leads).

Keeping the 12-cyl tacho happy required an additional function to be added to the SAW module ( although I recon this can be done in other ways too) and then I added a fuel cut relay to cut 12V to the injector rails in the event that EDIS-B should fail to prevent those with catalysts from frying their cats, so now is called the Dual Edis Signal Conditioning (DESC) module and I've made a proper PCB for it:

Chronological report

Update 21 June 09:
Upgraded to MS2/Extra RC3 2.1.0 yesterday by simply uploading the 2.0.1 msq. TPS based AE settings needed changing due to corrrected TPSdot measurement but other than that, perfect.

I also decided to change the injection regime from 3/simultaneous to 2/simultaneous due to the fact that PWs were getting uncomfortably close to the opening times of the injectors with 3/simultaneous. Still tuning but it does not seem like I've lost any of the responsiveness of the engine.

Update 23 May 08:
At long last I've "cured" the noisy CLT, IAT and TPS signals. All it took was NOT earthing these on the engine block but connecting them to an earth wire coming directly from MS.

Having LoZ injectors (6 of them per inj circuit) now worries me a bit that the remaining earth wire might be having a bit of a hard time. I'll be investigating that with my scope.

Update 14 May 08:
The Jag is running on 2.0.1 now.

The only "glitch" I had was the new MS-2/V3 unit I built for the 2.0.1fw was not happy with the 4k7 resistor in R12 whereas the unit running R2Beta 17 (and the unit in my Landy running 2.884) is happy with it. Although it was happy on stim with 4k7, I suspect that during cranking, the voltage drops to about 9V which results in the optocoupler just not getting enough current to work.

The newer LC-1 on the Left bank decides to report "heater circuit open" every now and then. I am really not having a good experience with LC-1s lately. 4 units recently deployed (in 3 different vehicles are all giving problems.

Update 28 April 08:
I recently tidied up some of my wiring (including connections feeding 12V to the injectors). Upon starting the car after this work I was shocked/frustrated that she was running "pig rich" as someone wrote on the forum. To cut a long story short, I eventually found that the injector opening time had reduced from 1.3ms to 1.15ms. This resulted in a significant enrichment at idle ( due to my 3/simultaneous injection scheme). It seems that my tidying up of the wiring improved some electrical connections to such an extent that more current could now flow through the injectors to such an extent that they opened quicker resulting in the significant AFR change.

Update 24 Dec 07:
Changed (a few days ago) afterstart tolerance under advanced timing settings to 50% and now she starts better than with the OEM ECU!!

Update 16 Dec 07:
Spent some time on setting up the baro correction table and now AFRs are more consistent. I just can not get over it on how much the engine's character has improved using 3/simultaneous rather than 2/alt. PWs at idle ARE VERY close to opening time but it seems less of an issue on the Jag than on the Landy (where some injectors don't open at all making the engine unstable - forces me to LOWER the fuel pressure at idle so i can have longer PWs OR match the injectors with injectors that have more similar opening times)

Starting is still not what it should be with the engine dying immediately after firing on that first few cranks. Can't figure out if I'm giving too much or too little fuel. One thing I want to try is setting the "cranking speed" very low, say 10, so MS goes into running mode immediately...

Changed PWM current limit to 20% (meaning 20% on and 80% off) and the injector PWM period to 90us and now MS runs only luke warm. Injectors are still being kept positively open even at full throttle.

Update 15 Dec 07:
Got the new MS/V3 into the car yesterday and took it for its first tune today running MS2/Extra Beta 2.0 fw for the sake of continuous baro AND dual WBO (perhaps 2 stage NOS later). Its running on single VE table at the moment and I will activate dual table as soon as dual table issues are sorted.

The increased torque at lower rpms, and snappier engine response on throttle changes is most noticeable. (Found the same on the Land Rover) Also, at higher rpms, the engine distinctly sounds more like a V12 than with 2/alt injection scheme.

I found the VE table to be "unstable" - not giving me the same AFRs every time I get to the same operating point, but that could be the MAT based correction and/or continuous baro messing me about.

Fuel cut on overrun also worked.

Without realising it, I had my PWM duty cycle set at the default 75%. Only when I felt MS getting very hot did it occur to me to check that an change it back to 30% because my 2.687 MS never got that hot. Will see tomorrow if this sorted the heat problem.

Update 6 Dec 07:
Busy building another MS2/V3 that will run on MS2/Extra firmware as that FW supports continuous Baro and dual WBOs simultaneously. Since it also supports 2 stage nitrous, I'll be going that route too...

Update 20 Oct 07:
Travelled 268 Km today - only highway, mostly 120 - 130 km/h. This is only the 2nd time I was able to travel a longer distance with the car.
Fuel consumption* (bearing in mind this is a Pre-HE) came to :
8.6Km/L = 11.6l/100km = 20.3mpg (US) = 24.3mpg(UK)
*Distance measured with GPS, fuel as per pump reading upon re-fill.

My friend's HE returned a very similar fuel consumption but one must consider that his engine runs almost a 1000rpm higher (2700- 3000rpm) than mine (2000rpm) at the same speed which again confirms the awesome efficiency of those HE heads!

Update 29 May 07:
The tacho feature was added to the "SAW delay" circuit and it turns out that the car's original tacho still worked!! It is now displaying the correct RPMs. The SAW delay circuit is now presenting the SAW pulse to the tacho at twice the incoming rate. This was the easiest to implement in the code. (4 additional lines of code). The MS fuelling and EDIS ignition side of things are now deemed fully sorted.

After fixing what I suspect is a knocking big end bearing, the car will go for a dyno tune to determine optimal AFRs at all operating points and then this project is done.

Update 11 May 07:
Figured out how to drive the tacho (rev counter). Either fit the rev counter from a Marelli based 6-cyl jag and connect it up to a PIP signal or use a circuit that will double the PIP pulse rate. The "SAW delay circuit" I've had developed, will be enhanced to include this doubling of the PIP pulse rate, as well as monitoring both PIP signals and disabling fuel supply in the absence of either to avoid damaging cats (if fitted) by dropping out a relay in series with the main 12V to the injector rail.

Update 27 April 07:
Fitted cold air intake ducts to the car today. Megasquirt was reporting temps of 65ºC up to 70ºC in town driving and around on 55ºC on freeway.
Now the temperatures are 27º - 34ºC. Interesting is to see how the air is still being heated through the air cleaner housing at idle due to its slow movement through the system at idle. Stuck some high density foam over the air cleaner housing for good measure (and because I had the foam and the time) :)
Pics at: ... 1177702011

Update 24 April 07:
The distributorless ignition system for the V12, based on using two EDIS-6 systems, is now working perfectly. I fitted a SAW delay circuit which memorises the SAW pulsewidth coming from MS to the A-bank EDIS and delays this pulse until after the falling edge of the PIP signal from the B-bank EDIS and then presents the pulse to the B-bank EDIS. This arrangement now delivers smooth acceleration all the way to 6500rpm.

FWIW: This circuit can be used on ANY EDIS equipped car with ANY
ECU (controlling EDIS) to convert the setup to dual EDIS for a coil-
per-plug or coil-over-plug solution or dual wasted spark as in this
case. This means a carburetted V12 can also be fitted with this
dual EDIS distributorless ignition system using Megasquirt or
Megajolt Light Junior or any ignition system capable of controlling
EDIS ignition.

Update 30 Mar 07:
Driving the car daily with no issues when driven "normally". Fitted the Magnecor leads with no noticeable improvement over the hodgepodge of leads I was using before. I'm not saying the Magnecor does not deliver but that the other leads were already acceptable in terms of EMI and RFI matched with plugs with internal resistors.

Moving the B-bank VR sensor clearly changed the PIP B vs SAW phase relationship but I could not get the B-bank EDIS to be happy, so I've set it back to its proper 60º location - where A and B-banks get exactly the same ignition timing.

Checking the B-bank advance with a timing light shows clearly that it advances as expected but this is only at 0 load. The hesitations above 4000rpm only manifest at or close to wide open throttle. I suppose it could also be possible that the 10º defaults occur so quickly that its not visible to the human eye but only detectable when driving the car.

Changing the MS-2 code to support "dual edis" seems too much of a challenge so I'm now looking at a hardware solution - which will also be more generic in that it would then work with ANY ECU supporting EDIS. Any single EDIS installation can then be converted to DUAL EDIS for what it may be worth.

Looks like my tacho is fried... :oops:

Update 12 Mar 07:
Managed to cure the "cutting out" referred to below today!! Car now drives very well again. The answer was to fit plugs with internal resistors (NGK BPR7ES). This reduced EMI considerably to the extent that the EDIS modules are now happy to be where they are in such physical proximity to the coil packs and right among the HT wires. Magnecor HT leads are on their way too.

Now I have only two more issues to sort:
1) EDIS module for the B-bank goes into its default 10º mode due to the incorrectly phased SAW signal it is getting. This only happens above 4000rpm and feels like "flat spots". However, I am confident that I can cure this by moving the VR sensors appropriately. It did work on the bench.
2) The rev counter (tacho). The problem here is that I don't know with certainty what type of signal really gets the tacho to work. The high voltage spikes generated by the coil primaries certainly DONT do the trick. I will now investigate earthing the tacho wire once per rev. Still need to figure out how...

During all of this I also changed the no of squirts to 2/alternating per engine cycle. Like it did on the Landy, it has made the engine run even smoother. Also, by setting the cranking speed to 60 (when in fact it is 150), the result is that it now starts - when hot - as soon as the injectors starts squirting - factory like! On the Landy, this trick did not produce similar results.

VR mounting arrangement seems to hold thus far...

Update 5 Mar 07:
Today the car started on Dual EDIS-6!! After establishing via the fantastic MS forum what the exact firing sequence of the EDIS-6 module was, the car fired up and again I found a noticeable improvement over the dissy setup, complete with MSD6A! (Found the same on the Land Rover V8..) There are a few "growing pains" to sort out, and I have not yet driven the car on the road, as it cuts out now and then for reasons yet unknown, starting is not how I want it, tach does not yet work but I remain hopeful that these will be sorted out in time.

Mounting the coil pack in the V was more of a challenge that constructing the coil pack assembly itself! It turns out that the distributor mounting flange is not horizontal but approx 3 degrees off horizonal - just enough for things to foul with each other! That means the "base plate" itself requires a base plate which is mounted at an angle to the plate on which the coil pack assembly sits (not shown in the drawings at the link below). Pics of installed system at :
(Please don't look at the wiring - this will get cleaned up as a project on its own)

What was particularly pleasing is that the EDIS "base timing" (SAW disconnected) which should be 10º was out by only 3º due to VR sensor positioning - easily fixed in MS software.

I'm not too happy with the VR mounting arrangement and will be trying to improve that - too much scope for issues.

Another interesting aspect is that the "EDIS Multispark" setting on MS-2 actually works. Looking with the scope at the Tacho output of the coil pack (where all the diodes off the coil- sides are commoned together) I could see that around idle EDIS was generating 2 sometimes 3 sparks per compression stroke but drops back to 1 spark just above idle. Would be interesting to see how this affects the rev counter (tacho) once I get that working.

Wiring diagram at: ... 1178105360

Update 4 Feb 07:
Having experienced a noticeable improvement on the Landy after installing EDIS, I decided to do the same on the Jag. I am now in the process of installing a dual EDIS-6 ignition system even though MS-2 does not yet officially support DUAL Edis. I made a bench setup similar to what will be installed on the car using one trigger wheel and two VR sensors 60 crank degs from each other. The PIP signal of the 1st EDIS system is used by MS for determining rpms and when to transmit SAW.
SAW from MS is presented to both EDIS-6 modules in parallel, even though the phasing of SAW signal for the second EDIS is way wrong as per EDIS documentation. However, the setup tested fine on the bench with both EDIS modules advancing properly.

I now have the trigger wheel mounted and the VR sensor mounting sorted after having first converted the mechanical fan to electrical. This made more space available and also freed up the fan belt tensioner pulley bracket for mounting the VR sensors. Pic (of temp install) here: ... 1170846543
Now comes the not so easy part....

Mounting the coil packs, and EDIS modules. I have decided that all of this is to be mounted in the V which would limit wiring to this setup to 12V, PIP, SAW, TACH and the two VR sensors. This will also keep the wires to the coil primaries short which I'm hoping will minimise radio noise. Rather than using 6 terminal EDIS-6 coil packs, I'm using three 4-terminal EDIS-4/8 coil packs which will allow me to wire it such that all the LH bank HT leads come off terminals on the LH side and ditto for the RH. Should look rather neat when done. Finding a mechanical solution to this requirement is proving to be quite a challenge. Recon I will crack it though using the original dissy mounting holes for a "base plate" onto which to mount a module holding the coil packs and edis modules.
Pics of the coil pack assembly here: ... 1170846543

Update 7 Nov 06:
Injectors running true LoZ with PWM current limit are still running fine. Latest MS fw 2.687 now squirts with every second tach event (for 10 and 12 cyl) during cranking but it still cranks more during hot start than cold.

Update 9 Sept 06:
As below except that I have now implemented true LoZ injector switching using Pulse Width Modulation (PWM). This was done after implementing the mods as found by Turbo4V. Using PWM has the benefit of opening the injectors as fast as is possible as well as limiting the hold-open current to the minimum, thus minimising heat dissipation in the injectors for best longevity. Even though there are 6 injectors in // per bank, the total current STILL does not exceed the built-in 14A current limiter.

At the same time I also implemented beta fw version 2.686t11, mainly hoping to have fewer injector squirts during hot starts to enable more control over fueling during hot start cranking. Previous code versions resulted in too many injection pulses during cranking - only a problem on v12 with 6 tach events per cranking rev.

Even though I took the car on the road for 1 hour this afternoon, I reserve judgement on the PWM approach but it would certainly be a much more elegant solution to having ballast resistors on the injectors with additional electronic hw to open them faster as mentioned below.

Below the status quo as on 1 Sept 06: (Non MS Forum subscribers can't see the JPG attachments)

Megasquirt 2 is now doing ignition timing and fuelling on this V12. I removed the original "Lucas OPUS" Ignition system and replaced it with a bog standard generic VR sensor (Fiat Uno 1400 VR HUCO part no 184976 ) rigidly mounted (ie no vac adv) with both centrifugal and vacuum advance disabled. Centrifugal was disabled non-destructively by simply strapping a cable tie around the weights. Picture at : ... 1157040671

VR output goes to Megasquirt 2 which controls a MSD6A via a TP100 ignition module. Load sensing is done via MAP sensor. Revs cleanly all the way to 6500 rpm. Taking control of timing has greatly improved torque at most operating points and has significantly improved fuel consumption under partial throttle (compared to the previous untuned situation).

I have fitted dual WBOs to first measure AFRs on the original ECU and found AFRs for almost the entire map to be between 13 and 14. At idle it went to 16.5 - 17.5 causing the unstable idle experienced by many XJS owners!! (With hindsight, the lean idle may have been the result of very dirty injectors - but then, how does one explain the rich mixtures while driving) The OEM ECU was not the correct unit for this particular 10:1CR engine though.

Having taken control of fuelling I am now able to lean it out to 16.5 (2000 - 3000rpm/40kpa) before lean surge sets in.

The low impedance injectors (2.5Ohm) presented some challenge.

Using 2Ohm resistors in parallel with the 4 existing 5Ohm resistors (per group of 3 injectors - see "v12 injector setup.JPG"), and switching the injectors as high impedance resulted in injector opening times of 1.4ms with very little difference in opening times between different injectors. This is imporant to ensure similar AFRs between different cyls.

Even though the car has been running fine for almost a month now, I was not really happy with this solution (concerned about injector longevity) and decided to implement a similar approach to that used by the OEM ECU - by adding additional electronics that would switch the injectors directly to ground but only for 1ms or less (adjustable with this circuit) and then using ONLY the original 5 Ohm injectors which would reduce the "hold open current" as compared to having the 2Ohm resistors in //. This concept is shown in the file "injector open concept.JPG". The actual electronic circuit diagram is shown in "inj open cct.JPG". The elegance of this circuit is that this unit can be mounted in the engine by near the resistor pack and is triggered by the two MS injector circuits. Ideal would have been to have 4 of these injector opening circuits - one for each of the 5 Ohm resistors :-(

As of this update, I have not physically tried it as I'm waiting for the circuit to be built, however since the concept is proven by the OEM ECU, my confidence levels are pretty high.

The six injectors on each bank are switched simultaneously. This allows individual fuel maps to be generated for each bank a feature supported by MS-2 sw. However, the AFRs are now very close to each other (after cleaning the injectors) such that I'm tempted to continue with a single fuel map. (It is somewhat cumbersome tuning with dual maps. The Auto Mixture Control feature of new releases may solve this issue)

I found that the injectors were VERY dirty and having them cleaned properly has enabled me to find even leaner mixtures (up to 17:1). However, for general driveability, I only have a very small portion of the map giving 16.5 during lean cruise. A much greater portion on the map now delivers 15.5 - 16 which results most visibly in reduced fuel consumption.

MS-2 injects fuel with EVERY tach pulse during cranking. On the 12 cyl, this easily causes flooding during hot starts where injection pws are rather critical. This matter will be addressed in new releases of MS sw.

Anyone interested in any Jaguar should visit - an excellent resource.
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Last edited by Philip Lochner on Thu May 25, 2017 2:36 am, edited 59 times in total.
Kind regards
My MS projects: viewtopic.php?t=20086

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Post by Keithg » Thu Aug 31, 2006 4:53 am


I have an opus distributor for a rover 3.5L. I am curious about what VR sensor you used and how it was mounted. Could you, please, snap a picture for me and pass on the part number?


Philip Lochner
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Posts: 45
Joined: Thu Feb 16, 2006 5:18 am
Location: Centurion, South Africa

Post by Philip Lochner » Fri Sep 01, 2006 1:03 am

Keithg wrote:Philip,

I have an opus distributor for a rover 3.5L. I am curious about what VR sensor you used and how it was mounted. Could you, please, snap a picture for me and pass on the part number?

Hi Keith

We are limited to 3 attachments in this forum.

HuCO part no 184976 Believed to be for Fiat Uno 1400.

Picture available at: ... 1157040671
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jaguar v12

Post by wester » Mon Feb 19, 2007 6:39 pm

I have just purchased an ms2 , stim,relay board,w/2closed element sensors which I will install in my 1976 v12 engine , after reading the manual I couldn't use the TPS from that engine and purchased one from ebay from a 1980 year model . Will this TPS work for the ms2? :?
This is my first experience with a megasquirt .
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Philip Lochner
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Post by Philip Lochner » Mon Feb 19, 2007 11:56 pm

Hi Wester

What are "w/2 closed element sensors"?

I'ld like to understand why you could not use the original TPS with MS-2? For sure, the 1980 TPS will work as my car is a 1980.

If this is your first experience, I would advise that you implement ignition only first until you have that sorted and then implement fuel injection after that (if needed). Remember that the OEM ECU still needs to get a trigger pulse off the coil for it to trigger fuelling.

When you do go for FI, take note of the low impedance injectors on the Jag and what you have to do to MS to avoid LoZ issues.

Have those injectors cleaned before you even start on FI. That's also a good time to replace the fuel hoses with fresh ones (kind of unavoidable anyway)

Welcome to the world of MS!
Kind regards
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v12 jaguar

Post by wester » Tue Feb 20, 2007 3:39 pm

Thanks for responding Phillip I didn't know if you were still watching this post or not since it had been so long.
The two closed element sensors are the IAT & CLT ( intake air temp. & coolant temp.)
The reason that I used the TPS from the 1980 engine , it was recommeded by Matt at DIYautotune , he said that the earlier version was not a true reostat and I found this one on ebay.
The car that I have the engine in is a home built hot rod that I built in 1991 the engine came out of an XJS that they converted to a V-8 , and I didn't get the ECU with it and have been trying to get it to run useing various carb and EFI methods with no good results . It still runs very rough and backfires even at a steady speed .
Now my wife wants to dragrace it so I have a new motivation to make it run good .
By the way what is LOZ issues ?
Information is abundant wisdom is scarce

Philip Lochner
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Post by Philip Lochner » Tue Feb 20, 2007 10:43 pm

Hi Harry

I've also been toying with the idea of having a V12 is some 4wheeled, 2 seat, open engined "thing".

Your V12 is not far from a happy life with wife and all! (assuming there is no mechanical issues).

The older TPS might have been a non-linear device which would have caused issues. Can't think of any other reason.

If you don't have it you WILL have to get a wideband oxygen sensor as well, otherwise you won't have a clue as to what your air-fuel ratios are.

LoZ refers to the Low impendance injectors we have on the Jag. This requires you to modify the V3 board in such a way that you take the active flyback current straight back to the +12V side of the injectors using dedicated wires. You will therefore have two wires to switch the injectors and two more to return the flyback current. I'm sure its written up somewhere in megamanual. Will find it and post it for you.
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V12 jaguar

Post by wester » Thu Feb 22, 2007 3:00 pm

Got the injectors back from cleaning last monday , and I'm taking your advice and will start with ignition first .
At this time I have an old 1973 set of carburators on the engine so it will run , which allows me to play with it some .
Getting back to ignition I assume that all the advance mechanism will need to be locked and use the MS ecu to advance it . From what I have read the jag has a three stage advance , I guess that I can incorporate that into the software .
Thanks for your help , I'm really very new at this , so I'll probably ask a lot of foolish questions , but not to bad for a 60 year old guy learning new tricks!
Information is abundant wisdom is scarce

Philip Lochner
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Post by Philip Lochner » Fri Feb 23, 2007 4:36 am

I suggest we take the rest offline? Will send you private mail.
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How are you hadling the grounds to the three coil packs?

Post by StevenD57 » Thu Mar 15, 2007 4:02 pm

Since you have three EDIS-4 coil packs but two EDIS-6 control modules how are you handling the ground wires from the coil packs to the modules? Are you running a common ground or what? As I said I am interested in any info you could share regarding wiring diagrams.

Thanks for all of the information so far.
Jaguar E-Types, modified Merkur XR4Ti, Jensen-Healey
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