ive seen this topic come up a few different times on this forum (the thought of converting to a standalone efi system on a Disco) and thought id collect my thoughts on the topic into one place - ill keep updating this as i get further through the process of converting my truck, although i have several other long term projects so this only gets attention when i have down time, but im determined to keep plugging away at it as ive toyed with the idea since i got the truck...


first, ill lay out a couple goals for the conversion, and some constraints, to help sort of box in some of my thinking behind what im up to, and why i made some of the decisions i did....
ill be focusing everything toward an MS3x conversion using my '97 5spd, although MS2e and other newer MS variants are functionally very similar, and likely more cost effective/simple for the first time user.
there may also be additional complication (although likely not a ton more from what ive seen in the RAVE) due to auto trans stuff on other trucks.

the overall goals:
-keep the existing harness with an adapter to the MS ecu. i havent completely decided yet whether this will be a parrallel install (with the lucas running the idle valve, emissions evap stuff, firing up the heaters for the O2 sensors, etc) or a complete MS3x control though im leaning toward complete control for simplicity's sake.
-MS3x will be controlling the check engine light (which it can set for failed sensors, etc)
-reuse all of the existing hardware - factory idle valve, both cats, all engine sensors, etc - in order to allow for simple swaps back to the lucas ecu if need be for emissions testing (although my county doesnt require it, several of the neighboring counties do and if i ever sell the truck i want it to be legal there)
-truck needs to function like-stock, as my parents sometimes borrow this thing for towing and yard work and i think the true test of a successful install is if you can hand the keys to a non-car person and they can drive it just like they normally would - this means that a/c will still work at idle, cold starts wont require some magic combination of throttle input, etc

specific performance improvements:
-remove the VSS interaction and phantom speed limiter issues that these things seem to have
-poor (in my opinion) closed loop control creeping in lower gears on the idle governor, and off idle launch quality with the 5spd.
-put the new ecu some place drier/safer out of the engine bay while making my adapter harness
-simplify the engine controls to rely on fewer sensors (sort of goes along with removing the VSS interaction), but this means running batch fire injection (like the injected V8s that they sold in other parts of the world) and eliminating the need for a cam sensor, post-cat O2s, etc
-and likely the biggest one, leaning out the engine during light load highway cruising to get better mpgs. some MS users are claiming ~20mpg highway with trail ready rigs (big tires, bumpers, winches, etc)

i realize many of these performance goals could be accomplished via a "tuner" for the stock ecu but i havent found a good solution to that, and im familiar and comfortable with MS that i thought of it as a viable solution.


ive got a pin map most of the way done of what pins ill be reusing from the stock ecu, which connector they live on, and which MS3x input/output it will line up with.

the truck will get tuned with wideband O2 sensor(s) then once tuning is complete id plan to run the map partially closed loop on the existing pre-cat narrow band sensors, with altitude correction (as this is my ski rig)

my reading through the electrical diagrams of the 97 NAS ECU controls has me thinking this will be pretty straightforward, as in the end the simplest install will essentially mimic the batch fire scheme used on the ROW v8s.
ive done numerous MS installs both parrallel and standalone on various different makes and this doesnt really look any more daunting than any of the other 90s era cars ive run across.


ill post more as i think of it, including attaching the pin map ive made as soon as ive got it finished (90% of the way there, just ran out of time last night)
thought id post here to bounce ideas off you guys and so i can have some place where everything is written down... because my memory sucks haha


...dont want to turn this first post into too much of a novel...


cheers!

 

Best of luck! I'm curious on how it turns out

 

If you figure a way to integrate the OBDII outputs.....that would be golden.

Good luck and may the force be with you.

 

theres really no practical way to do that. leaving the stock ecu online and disabling its control of the fuel/spark/idle control functions is probably the closest thing, but it will likely be setting codes and would therefore still need to be converted back to the "stock" mode (via just reconnecting a couple of connectors) to pass readiness. the conversion to the standalone would remove control of the MIL light from the GEMs while the other ecu was plugged in.
when it came time to emissions test, youd reconnect the stock lucas stuff and be back in spec for emissions (im planning on leaving the cats alone)

 

alright, ive come to a little snag and to save some effort when it comes time to install this thing, maybe you guys can lead me to the right spot...

i had a look through this, as well as the RAVE, and wasnt able to find specifics...
https://landroverforums.com/forum/di...-manual-47986/

but im after any electrical specs i can get on the MAF (not a big deal), idle stepper (also not a real big deal at this stage), the intake air temp (this one is important), and a verification of the coolant temp resistance values i was able to find in the rave.
itd also be nice to know the resistance curve of the fuel temp sensor, but also not a huge deal at this point...

i tried googling the lucas part numbers i found in the RAVE but wasnt able to find any other forum discussions on the sensor specs.


heres the working draft of the pin map and the other random info ive collected so far...
http://www.spitfireefi.com/files/LR-MS_pinusage.xls

 

https://landroverforums.com/forum/at...ionsystems-pdf

Take a peek at this for values of various sensors and models of Rover injection systems. The blokes in the UK have been squeezing Rover engines under the bonnets of all sorts of rides for years, and converting carbs to injection, and injection to carbs; lots of stuff on the internet.

Also see Morgans, much info there - http://www.gomog.com/allmorgan/gemsPLUS8.html and http://www.gomog.com/allmorgan/GEMS/GEMSbyPoole.pdf

 

That was my same conclusion.....which stopped me from looking any further. I wanted to gut the entire stock system.

 

i dont see it as a problem to have to use the stock system when youre about to pull into the testing station and immediately unplug it after. for the other 99.999% of the time youre using the truck itll be running much better, and using less fuel

kind of a non-issue for me either way as i dont have emissions tests (and perhaps someone attempting this in a state without them might just gut the whole thing and forget it) but id like to leave the option open if someone else buys this and wants to get it smogged.

im also leaning toward leaving the stock stuff in there to run the more mundane things like the evap control, the O2 sensor heaters and the a/c clutch control.
this should greatly simplifiy the conversion and leave those outputs open on the MS for more interesting things.


thanks for the links Sav, i found the overview document in that other thread you posted it in, but it also doesnt have specifics on the sensor electrics. more of a general overview.
with how often these engines are modified in europe im surprised the lucas specs arent easier to find!

that morgan document has some info on the air temp sensor - looks like its a straight line for resistance. ill add those to the spreadsheet tonight.
that morgan document is also the first time i saw any mention of the number of teeth/spaces on the crank trigger wheel, which will be very useful info. sounds like a generic 36-1 wheel, now just have to figure out which tooth the sensor is on when the engine is at TDC... would prefer to have that in a manual rather than having to count teeth when it comes time! hah

 

There is a missing tooth for the sync point.

 

yup, thats the 36-1 part, and the morgan manual seemed to suggest that was the case, but the tooth # that the sensor sits on when the engine is at TDC determines crank timing.
i doubt thatll be anywhere in the manuals though so thatll probably require counting them off when the time comes...