I did a quick search and couldn't find the answer to this:

What are the main functional differences betwen JDM and US engines? Specifically, I am interested in buying a JDM engine/tranny/harness/ECM package, but I don't know what year vehicle it came from (and I don't want to take the importer's word for it).

I know they got away from the vacuum solenoid rail at some point (1999?), and I have seen some coolant necks that appear to be cast as a single piece rather than having a plastic upper portion, but other than that I am clueless.

Bottom line - should I make every attempt to get a 1993-1995 JDm engine, or will it be easy to make any year engine work? Should I plan on using my existing wiring harness and ECM, or are they all identical?

Thanks!

 

If you're planning to run a highly modified engine with few of the stock accessory systems it probably won't be a big deal if you get a newer engine. I don't know how the hard parts vary specifically but they should be similar.

But if you're trying to drop into an engine bay with stockish setup you'll want to have the early design for the 8-bit ECU. Later models have a 16-bit ECU and the wiring harness is different.

David

 

Thanks dgeesaman. Do you happen to know what the last year of the 8-bit ECU was for JDM engines? 1995?

 

You will need to also do minor re-wiring to make the JDM engine harness work. There are a few threads on it.

From experience they are cheap alternative but a pretty big risk because no importer will actually warranty them.

8 bit only came till 95 as a series 1 FD. The 16 bit version is more costly and not worth the hassle.

 

Thanks Polak. I plan to use a place near my house when/if I do this. They allow compression tests...I've already pulled out the Schraeder valve on my compression tester in anticipation! They seem as though they will warranty parts for local pickups (not in writing though), but every importer I have ever met is shady.