DOES any one have a dump of the ignition timing maps for the 26CU?
I would like to understand the advance curve timing strategy...

 

This may be an interesting read to you

VACUUM IGNITION ADVANCE / AJ6 Engineering

I would consider looking for a megasquirt thread or similar. Idk if anyone is going to have what you are looking for, but a detailed megasquirt build probably would.

 

I don't have a dump of map from 26CU or 36CU but do have a document for training on Jaguar engine management systems for AJ6, AJ16 and V12 engines that may be useful.

By the way If your question was regarding ignition advance then this is handled by Marelli MED 123E, the Lucas 26/36cu handle fuel injection .

I tried to upload engine management training document but it's too large.
Click on mega link below to download this

https://mega.nz/#!HMxC2KAS!paXz-dCdK...xmaXZLtJmY4xPk

 

downloaded and sent to iphone placed in my ibooks

 

I have been thinking about this too. I have a Megasquirt sitting on the bench I am modifying to run distributorless.

A good place to start with advance curve is with the Lucas standard dissy curve, then tweak from there. I haven't asked my engine builder for this yet, but this is where I plan to start.

 

hey I would like that info if and when you get it....

 

Paul_59- That is a fabulous manual. Thank you for that. I learned two things I didn’t know: My 92 V12 XJS won’t throw a DTC unless there’s at least a gallon of gas in the tank, and if the throttle position sensor is wide open when cranking, the injectors are not fired. Both are applicable to my non-running car. Can’t wait to test that throttle position sensor and put a little more gas in the tank (it’s very low because I replaced fuel pump and only put a little in) -John

 

There is a guy in South Africa who has put Megasquirt on a V12, but I've not seen his timing values. I've certainly never seen those numbers published anywhere officially.

 

That's very standard across almost all EFI systems as a "clear flood" mode.

 

Timing for the HE is in the ROM it lists timing at 3 points in the RPM range, this is what I was planning to use as a basis for my Megasquirt.

 

Does it say what the manifold pressure is for those values? the main table will be a 3d table.

 

Decel timing for the HE

2000rpm 12-16°
4000rpm 18-22°
6500rpm 20-24°

Vacuum advance for the HE

max advance is 12° @ 15inHg and vacuum advance starts @ 5inHg

This is directly from the ROM engine Tuning Data -5.3L page 05-1

 

Warren, Is the above data (your post no.12) the Lucas data? As I thought that it was timed at 18 degrees advance at 3000 rpm. Excuse my complete ignorance of all this sort of stuff.
Greg

 

Yes that is the Lucas data for the vacuum advance distributor. There is no data for the Marelli as it is done with smoke and mirrors.

There are a few on this forum with megasquirt V12's maybe one of these guys could chime in and give us their msq's which will show the timing they run.