DIYEFI.org Forum

This is the build comment thread for my Jaguar XJ12 project found here.

Compassion wrote:Rear diff swap (ratio differences)

What is the stock ratio, how strong/big is it, and what is the ratio that you want to use, and why? Just curious, may have an opinion that you'll be free to ignore :-)

-Fuel pressure gauge

Not necessary, you should be able to hear the fuel pump load up when it starts, and feel the flow out of the regulator once pressure is there.

-Multi-channel Logic Analyzer

Not necessary either, only for helping test code for the dev team, and even then, you can do a lot without one. Very useful though, for 5v stuff :-)

-Two Wideband O2 sensors for tuning purposes

Did you see Peter's log? Those SLC_OEM units seem to work very nicely :-)

-12 Cylinder Tach appeared for only 1973 and might be shared with the Series 3 E-Type and made of unobtainium

No need, freeems tacho out will likely solve that issue for you if the input signal is high enough resolution.

-Some concern on maximum advance available with EDIS

FreeEMS itself will likely have the same limitations, why do you want more than that? How much do you want? Why?

-Crank-driven (essentially) Distributor-mounted CAS adapter (mostly for a drop-in solution for other owners)

The community will love you :-) Josh and Nick are heros for that in Volvo land.

-Need to source coil-near-plug ignitors for project

Not if you go LS1 coils. And almost any ignitor will do fine. Matching it with the coils is a good option, but not necessarily required.

last generation on 1996 XJ12 were high-z Nippon Denso, but made of unobtainium)

They only have to be physically compatible (not even identical) and between enough and twice enough of flow and you're fine. There MUST be suitable injectors for cheap on ebay for it. Can you spec the originals? Link to witch hunter for the originals?

I'm also looking into going from the GM TH400 and doing a 5 or 6 speed manual conversion for the car

That would be so sweet :-)

When you start on a DIY circuit bang up a thread for that in DIY HW :-)

Fred.

What is the stock ratio, how strong/big is it, and what is the ratio that you want to use, and why? Just curious, may have an opinion that you'll be free to ignore

I'd need to go see if the tag is still under there. I'm expecting a 3.54 Salisbury 4HA, with that original 4.2L I6 & Borg-Warner Model 12 but it could go in either direction. It's not high on my list of things to solve right now, because the original will work fine for now, assuming the diff isn't burnt out or requiring an overhaul. Going to have to sort out calibrating the speedometer with the GM TH400, though. Any good transmission shop should be able to get me the gears I need for that.

The later V12s had a Powerlock/Limited Slip 3.31, 3.54 (again, but 'Power-loc') or a much taller 2.88 for fuel economy. The Jag XJ6/XJ12/XJS mostly had Salisbury 4HAs with some Dana's thrown in during tough times.

-Fuel pressure gauge

Not necessary, you should be able to hear the fuel pump load up when it starts, and feel the flow out of the regulator once pressure is there.

The Bosch fuel pumps have a propensity to partially fail from that era. It's become a common-knowledge/requirement for care on these cars to have have a provision for connecting them for diagnostic purposes.

Not necessary either, only for helping test code for the dev team, and even then, you can do a lot without one. Very useful though, for 5v stuff

It doesn't hurt to have a logic analyzer for 5V purposes. Plus, it's not like I won't be using it for my other projects that I have to debug on my own. Invariably, I'm sure it'll come up.

I noticed you didn't comment on the 'scope, therefore, I take it that you completely agree.

Did you see Peter's log? Those SLC_OEM units seem to work very nicely

Yeah, I read about them. Looking forward to getting a pair I think. I was considering one LC-1 and seeing how it stacked up against that ATMega-based open-source project, but I figure that'll just keep me from getting actual work done.

(Re: Tach) No need, freeems tacho out will likely solve that issue for you if the input signal is high enough resolution.

The issue is more that the stock tach doesn't hit red-line and I'm going to have to make a driver circuit for it. 6 or 12 it will end up interesting and I wouldn't be surprised if I ended up 555-timer based. I'm figuring I'm probably going to have an LCD read-out sitting on the parcel tray or stuck to the dash till I work that one out.

-Some concern on maximum advance available with EDIS

FreeEMS itself will likely have the same limitations, why do you want more than that? How much do you want? Why?

The HE motor has 11.5:1 compression and a bit of a complex advance/retard map from trying to solve emissions, economy and performance issues.

From looking at commentary with some experienced people with the HE V12, this appears to be the breakdown, as an overview. I can ask Phillip about the ignition map with his Dual-EDIS with the setup he did. It might not be as severe... or maybe it might end up being that way and I get to move on to say LS1 packs.

Extract from Jag-Lovers:
-Max mechanical advance 24 degrees @ 6200 rpm Plus 12 degrees vacuum advance starting at 17.0 kpa till 51.0 kpa.
-Maximum advance at light load condition 46 and 36 degrees

Not if you go LS1 coils. And almost any ignitor will do fine. Matching it with the coils is a good option, but not necessarily required.

They were on my list of potential options, too. Just not there yet

last generation on 1996 XJ12 were high-z Nippon Denso, but made of unobtainium)

They only have to be physically compatible (not even identical) and between enough and twice enough of flow and you're fine. There MUST be suitable injectors for cheap on ebay for it. Can you spec the originals? Link to witch hunter for the originals?

I'll look into it. Trying to ask someone with that car and working with those injectors so I can find out. Any commentary on what the ideal or acceptable duty cycle range tends to be?

I'm also looking into going from the GM TH400 and doing a 5 or 6 speed manual conversion for the car

That would be so sweet

I'm looking forward to it. It'll pretty much probably involve pulling the motor out for the changes needed. Well, I probably could do the flywheel in-situ. I'll just think about that.... LATER.

I'm going to start grinding at KiCad this weekend and make a mess of things. Don't be surprised if some garbage comes out at first.

The Bosch fuel pumps have a propensity to partially fail from that era. It's become a common-knowledge/requirement for care on these cars to have have a provision for connecting them for diagnostic purposes.

OR, put a reliable pump in from the start. It's not worth pissing around with old components in that area. Put in a new Bosch pump and ensure the tank, lines and filters are clean, leak free and in good condition, and go from there :-)

I noticed you didn't comment on the 'scope, therefore, I take it that you completely agree.

They're always useful. The LAs solve certain problems that a scope just can't, but the scope tends to be more useful overall and can do a lot of stuff that the LAs just aren't even designed to do. The system itself has and will have some functionality of both devices built in, though, so neither are strictly necessary from a user perspective.

Extract from Jag-Lovers:
-Max mechanical advance 24 degrees @ 6200 rpm Plus 12 degrees vacuum advance starting at 17.0 kpa till 51.0 kpa.
-Maximum advance at light load condition 46 and 36 degrees

That's easily within both EDIS and FreeEMS limits.

Any commentary on what the ideal or acceptable duty cycle range tends to be?

The internet says "max 85%" but reality and FreeEMS say "max 100% fuel duty in your coldest conditions". Realistically you want the smallest injectors that you won't max out. Somewhere between 50% and 100% duty = perfect AFR at max torque will produce good results. You want a little headroom, so 100% is not a good place to be, and you don't want excess headroom esp if you've got a high power to displacement ratio (which you don't) as idle becomes more and more touchy and difficult to tune. If you go close to 100% then you'll go into a non-linear region which will cause AFR variations, usually from normal to richer.

Fred.

PS, I fixed all of your quote tags, and it took a while :-p

Hate to be the one to break the news, but you're going to have to run KiCad as a windows version in wine to get decent performance in the PCB editor. It's glacial as a native OSX app, sadly. The win/wine version is only ugly, it's not too bad :-)

Fred wrote:Hate to be the one to break the news, but you're going to have to run KiCad as a windows version in wine to get decent performance in the PCB editor. It's glacial as a native OSX app, sadly. The win/wine version is only ugly, it's not too bad

That's actually KiCad in Windows. Look a little closer. I'm running Windows 7 as a VM under OS X. I can swap over to native windows when I need to.

Also, I do have a build comments thread. ;p

That's actually KiCad in Windows. Look a little closer. I'm running Windows 7 as a VM under OS X. I can swap over to native windows when I need to.

Ahh, so it is! Nicely done

Also, I do have a build comments thread. ;p

What ever do you mean?

I hear you have some hardware related questions? fire away and I will answer them as best I can mate.

Compassion wrote:I talked with Andy/DeuceEFI about the the pin assignments for the above.

After everything that has happened in the last month or so, both you and Andy should bloody well know better than to do that. Your two sentence summary wasn't clear enough to comment on, and because, as far as I can tell, the conversation you had wasn't in the FreeEMS-public domain, you're, once again, out of luck. Furthermore, you were offered direct help from Dan, who knows this stuff most intimately, besides me, and didn't even have the courtesy to respond to any of his many attempts to communicate. Extremely poor form, Evie. Keep the technical conversations, be they support, FOSS-design, or random discussion, in the public areas specifically created for such purposes. To not do so is to screw those who follow you out of valuable information AND to leave yourself and your advisor(s) ignorant when they make mistakes due to zero peer review of their comments and instructions. Pick up your game.

I hope others speak up and back me on this, as it's not in the spirit of the project and just wastes everyone's time.

Also built FreeEMS firmware using the Windows Toolchain, although I got a bunch of git errors, but as far as I know it built successfully.

Unless your "make s19" goes smoothly without any errors, then you've not built a supported firmware successfully at all. Get msysgit, and build it in there.

I could not get the FreeEMS Loader to work on the Windows Toolchain, so I moved onto Megatunix for its mtxloader. I found out that its broken on Windows till the serial stuff gets cleared up. I've already mentioned the issue to Dave and he's working on that.

AFAIK there is no binary windows distribution of the loader. This needs to change, please log into the issue tracker and vote on or create an issue on the loader to get this done. Without you expressing the demand that exists to the author, nothing will happen. Again, in silence, you're screwing others. Realise this.

I was able to flash my build files onto the TA card. Success. Sort of. I kept getting garbage out, when I'd hook up with it.

Get a clean firmware build loaded first, it could be broken and corrupted internally. Thus, until you have a clean s19 to load, you're potentially wasting your time, and that of others.

It looks like the FT232R and SP232A just don't play nice!

Rubbish. They work fine. How do you think I develop firmware every day? Look to driver versions, serial settings, logging applications, dodgy hardware in between, and other issues, for your root cause. The SP232A is a simple device, it's effectively pass through to the FTDI chip.

Is the 4-pin RS232 header header generally direct to the S12X? If it is, I can take a stab are just wiring up an FT232R(L) directly to it and just side-step the DB9.

Yes, but to the wrong port, you can't use it without significant hacking, which will rule you out from using pre-built binaries from me in future.

Fred.

Compassion wrote:I'm working on the PSU, submitting that to my father and the community who know the system, application of it and field of endeavour best for review

Fixed!!! Why take the failure-prone path of greatest resistance all of the time? :-(