XJS build thread-- upgrades and Modern ECU

Hello All !
I am posting the beginning of a build…
to upgrade the XJS with modern conveniences like
Sequential Injection& spark, dual ETB’s, Coil on Plug, dual MAP’s, Manual 5 speed AR-5, race clutch, and more
the hope is to have a running car!?.. someday…
and after that, who knows!?


Sounds like and fun (and ambitious!) project.

What are “dual ETBs” ?


Electronic throttle bodies?

yea, i have 2 GM electronic throttle bodies mounted up currently
2011 Chevrolet Impala 4dr Sdn LS v6 3.5L LZE
VIN: 2G1WA5EKXB1226688 and VIN: 2G1WF5EK4B1132002
i will post a more complete list of the new goodies soon
along with pictures

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Coil on Plug fits just fine…need to anchor them in… Also got a Fuel Rail (and matching intake manifolds from a 6.0L, and fits nice too – Put in Deka ( BMW) fuel injectors from some early 2000’s junkyard scavenging…
injectors from 2004 325i and
i think 2000 BMW 528I --VIN: WBADM6343YGV03920
Siemens 13537546244
215cc 14.3 ohms 3bar
Siemens Part Number: A2C59511971
BMW Part Number: 1427240 / 7546244
Qstat: 162 g/min (n-heptane)
Flow rate: 237cm³/min @ 3.5 bar
Minimum injection time M52TUB20: 0.640ms
Minimum injection time M52TUB25/28: 0.624ms
V ms
0.0 3.65
6.0 3.65
8.0 1.84
10.0 1.23
12.0 0.81
14.0 0.55
16.0 0.39
25.0 0.06

bosch 0261 230 416
from rock auto new – VAG

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Also put in a fire wall between back seat and trunk…

ECU located. ready for install . It’s a RusEfi proteus unit-- will do 12 cyl sequential injection and ignition.

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ETB info

Pin Wire Color Description
A BRN Throttle Actuator Motor Control
B YEL Throttle Actuator Motor Control
C TAN Ground
D DK GRN TPS 1 Signal
E GRY 5 Volts
F PPL TPS 2 Signal

Very very cool
How do you know what parts to use from General Motors and others is beyond me.
Once cars went to this stuff , electronics etc, I stopped paying attention.
I am thinking of adding a XJS to my garage but just looking at the engine scares the hell out of me. On the other hand, I can rebuild anything without computers , sensors etc in my sleep
Slowly getting into understanding these types of cars, must be a general rule of thumb that ties all together
Good luck, keep posting

basically i ask on the RusEfi Slack Channel,
and people say " do / get Blah Blah" …
so i do that…
i don’t have a lot of original thoughts! hahahaha
i will post a more complete final list once all the bugs are worked out… some hardware may change over the next year…

Surprised so many parts are interchangeable with BMW m GM, etc
Send pictures showing the entire car too
You have the v12running?
What was wrong with it?
What year?

the Jag used “bosch standard size” fuel injectors, a bosch licensed ECU, etc… the only non-bosch thing is the crank timing setup…
not running currently, since still installing the fuel cell… although it did fire up a few seconds with starting fluid
1989 XJS, but i have a 1987 backup v12, and a 1995 backup 6.0L v12 also
whats wrong with it? someone gave it to me for free, and it has been sitting for 15 years … outside…

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here are some pictures of the 36-1 trigger wheel and pickup-- a BMW CAM (Hall ) sensor .
Cheap, and works great. i used washers to get the proper spacing for the gap. Fabricated an alum bracket to hold the sensor.

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in other news-- the AR-5 (Solstice) manual transmission / 6.0L combo is coming together… need to get some welding done …

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Removing the heads from the 1995 6.0L and 1987 5.3L
Using the usual home made steel plate with holes threaded … that people use all over the world…
sprayed it with PB blaster to loosen up the crud, and used $20 harbor freight air hammer to vibrate the studs ( put on a nut first to protect the threads .
the heads come off… with the usual hassle and pain…
hopefully have enough parts from the two engines to make one good runner…
more news later…

The 6.0L is stripped down…the crank has one con rod journal bearing eaten up by a spun bearing…
UnHappiness! The crank is screwed… will have to try and salvage a 5.3L crank and pistons… and install into the 6.0L block… which is pretty well preserved in general… shame about the spun bearing, because everything else is great…

5.3 cranks have a shorter stroke :frowning:

well, the 5.3 crank, con rods, and pistons would go into the 6.0L block… except for the rear seal… the rear seal is all different in the actual block… so instead of machine shop mods, i guess i will just used the 5.3L block with the 5.3L crank…
bummer that the 6.0L block and crank are not gonna work out…

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A good machine shop can easily stroke that 5.3 crank to a 6.0.