Later engine in early car - part 2

[porschetub]

Hi to all ,have traced one of the mystery wires to the sump/oil pan level /temp sensor? (not sure which )presume this goes to instruments don't know about the other 3 still ?.
Have removed auto transmission coupling ,rear seal is excellent as I suspected for a 30,000 mile motor (have new one to fit ),lots of rubber fragments to clear out as rudder centre was 80% toast.
All belts ,pulleys and seals all good on the 2.7 unlike my old 2.5 ,probably the most leak free all alloy motor I've seen.
Still trying to get 2.5 removed but lots of corroded exhaust bolts??? .
Also noticed no O2 sensor on the early cars exhaust ,will use the non-cat centre muffler and front pipe off the 2.7. then there is no need to weld in a fitting.
Have found some info on this swap but there is WAY more involved than many people say
Will keep all posted on my progress,thanks

[914efi]

It's not that bad if you have the late computer. I did an '86 8V into an '82. I did spend a lot of time understanding the wiring diagrams for both versions.

I used the wire for the early style heated aux air regulator to power the heating element for the 02 sensor, same basic function for the wire, just to a different location. I was worried the the engine would need some kind of aux air control for warmup, but the computer sorts it out fine using the stepper motor idle stabilization system. I have not hooked up AC yet, so maybe some glitches there...

If you have specific questions, I might be able to help. Study and understand the wiring diagrams.

[porschetub]

Hi all and thanks 914efi ,yes I can see how the old cold start feed would work with the oxy sensor,I will run over with my tester and do that.
I notice old (85) and later (89 2.7 ) computer loom to fuse box plugs are colour coded the same,early is 9 wire later is 11 wire,were do spare wire 2 wires go on the later plug?,thanks

[porschetub]

Hi,checked the cold start heat feed on my 85 loom and its colour for colour on later 89 loom (wire #4) which is to the oxy sensor.
I'am going to not worry about the spare wires @ this stage,hope it will start any way????
Torque tube now fitted to motor and clutch p/plate tightened up,I did it this way as I didn't have an alignment tool and it worked great,clutch slave cylinder overhauled SO much cr@p in system works better now as car has always had a heavy pedal.
If all going well hope to start engine in the next day or so.

[914efi]

Yes, the colors pretty much match up. The 'extra' wires can be insulated and not used, but I don't remember exactly which were which. I can check my notes when I am home. I think one of the extras was related to the tach?? There is a connector for the altitude switch which I left loose, I am at sea level and it only leans it out, so worst case is it is rich at high altitude.