EFI issue, swap in a series 1 head?
 

My 1985 XJS v-12has been giving me some issues with brittle and broken wires. I found a local seller who is selling a 5.3l v-12 from a series 1, and as such has stromberg carbs.

Can I swap the heads from the series 1 onto my XJS and just delete the EFI altogether? Or is this too good to be true?

I think it would be a step backwards to go from EFI to Carbs. The V12 was supposed to be released with EFI but due to some legal issues with (I think) Bosch, they had to hastily throw 4 carbs on at launch so apparently it was never a great set up to begin with. It's not a big job to make your own fuel injection wiring loom (basically it's only 5 wires). You can buy the Bosch connectors off ebay and all in you're less than $100. Plus it's a satisfying job when you've done it, and you can also route the wires differently and get them up out of the floor of the engine "V" This means you do the job once and you'll probably never have to do it again.

Sure.... if you don't mind changing 12 pistons at the same time :-)

Cheers
DD

Huh, had no idea it was a different block.

I know with Hondas, some larger heads can be fit onto different blocks. Just thought it might be possible here.

The series 1 "block is seized"

As Doug said, the pistons are different, the fuel pump will need changing, and many, many little things just will NOT be right. Your TH400 will NOT fit properly, the crankshaft is different (carby V12's were BW12, and a smaller spigot diameter)

The amount of time and effort would see you rewire that WHOLE engine bay 3 times.

HONDA, thats a "pretend car" is it not, really ??????. HAHAHAHA.

Doesn't Honda make lawn mowers?

Anyway why not just take the time to fix what you have? It is going to take way more time and effort to get some carb setup to work. In the end you will have taken a step backwards.

I know it might seem easier to go to carbs because EFI is intimidating. Why not spend the time reading and figuring out how the system works. Once you know how it works you can fix it.