I just went through this with my 4 Runner. I bought an 87 4Runner that need an engine. I had an engine from an 85 4Runner with the harness & computer. I used the 85 computer with the 87 harness & the 85 engine. I couldn't get the timing right. It was 30 degrees btdc. I did alot of reseach to find out that the 85 EFI computer is different than the 86/87. The 88 is different than then years berfore. I stopped there so I don't know if they are different after that. The difference between the 85 to the 86 is the engine harness. The diagnostic plug is on the driver side on the 85. Toyota changed it in 86 to the right fender. After I got an 86 Computer I was able to prpoerly time the engine. Before that I had tried everything. The 85 will work as a test but if you live in an area that you have to smog the engine, you will have to get the right one from an 86/87. I know Napa Auto parts can get them for about $300.
