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Late Series III motor/FI into a Late Series II XJ?

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bmurphy7369

bmurphy7369

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Just an idea posed by a member in Indiana who has a beautiful 1979 XJ6, SII for sale. What would the difficulties be in using the engine and fuel injection from my '85 XJ6 to power the Series II. My first thoughts would be the wiring harness nightmares, but it may not be that difficult. The other issue would be the fuel delivery. If anyone has attempted this or has any thoughts they would be appreciated. It may be an interesting project (or a Lucas nightmare?). Thanks for any advice or opinions you may have.

Brian
 
Brian,
It was my understanding that the 1979 Series II XJ6 was fuel injected already and in fact, according to my catalogs, uses the same injectors as the 1985 XJ6 already. What would be the improvement??

Webserve
 
Web,
It's not a matter of improving the Series II, I just considered using the engine from the III due to the 1979's need for a motor. I think the difference I am seeing is probably in emmisions, EC modules/electonic 'stuff' that control air/fuel, etc. I haven't seen under the hood of a fuel-injected SII (mine is a 1975 ZS), though, so I guess I am assuming it has the old throttle-body (simplistic by today's standards)early FI systems seen in Volvos and other late 1970's European (Bosch's early design) cars. I need to do the research, a picture of the late SII engine bay would be helpful. There may be no difference at all, maybe the air cleaner housing? This idea just came up last night, need to work on it. Sorry for the confusing post... Thanks for the reply, if you have any more thoughts, please let me know.

Brian /ubbthreads/images/graemlins/cheers.gif
 
As it is my car that brought this topic up, I feel I should chime in here. My car is a late series II, with the Bosch EFI system. I don't recall offhand which system it is, but as far as I can tell, many of the parts are interchangable, with the exception of the ECU, which changed at some point.
The real issue with my car is not necessarily that the motor is bad, but previous owners have bodged the underhood wiring and fuel injection system to the point of complete confusion (at least on my part). So it would seem that a series III system could work, if it were transplanted in it's entirety.
It isn't necessarily something that I would want to tackle, but it is an interesting question. What else is interchangeable?
 
Brian, I have encountered differences in the series II vrs. series III XJ6 involving relays (such as the ECU master relay) that can become problematic. This pertains to parts availability. The series II also was produced under the British Leland disaster. I would suspect that the fuel injection ECU wiring harness is quite different. My instinct tells me to avoid a series II to a series III fuel injection conversion. If it involves replacement of the wiring harness and the ECU, forget it. The series III was a great Jaguar model. The series II was not that great. Start your project with a genuine article. Best regards.
 
Jack,
That's sorta what I was thinking. I have a question for you: How can I tell if my '85 XJ has the POSI-Track rear IRS? I have had a request for the part, but have no idea how to tell the difference. Thanks for your input, as always.

Best wishes,
Brian
 
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