SoCal Driver

The "S" models are a different beast as far as the DME and wiring than the 944 or the 951.

So even if a plug has the same number of pins it most likely has different wiring than it's siblings.

But using the entire harness from the 951 including the brains and instrument cluster should prevent 99% of any problems.

Also note that there is one speed/reference sensor for the "S" models as well as a special flywheel. The 944's and the 951's use two sensors.

I don't have the electricals for the 91 S2. Think the earlier "S" has the same wiring. I'll look if I can find the time.


What happened to the engine out of the S2?

Danno

Best to get wiring diagrams from both cars and trace each and every single wire by function. I think the S2 also uses a separate hall-sensor for driving the tach; the signal doesn't come from the DME like on the 951s.

The S2 uses a flywheel triggering system that some missing teeth on the flywheel ring to indicate positioning data, so you don't need the reference sensor. So you'll need the 951 flywheel and clutch.

Maciek

Thanks guys for all the responses, basically, I need to get my factory manuals on cd which happen to be in storage because my family is in the middle of a move so I do not have my wiring diagrams with me. I believe SoCal driver is right, that I need to take the interior wiring from the 951 and put it into the S2 along with the guage pod and everything. With a few exceptions, basically everything should work with that. The S2 engine had an engine fire, so I am replacing everything in the whole engine bay with the exception of the power steering rack with the engine bay of the 951, so the 951 flywheel and clutch will be used. Thanks again guys for all your suggestions. My dad is an electrical engineer, so hopefully we will be able to figure this one out. Thanks,

Al P.

Sorry to jump in on the post but I'm in the process of putting an early NA motor in an 87 NA car using the entire wireing harness from the 87. Any thoughts on potential problems other than the oil level indicator?

Tom Carson

use the 87 AFM & DME...temp sender prolly has only a single connection for the gauge so you lose the idiot light the earlys didn't have...and get your own thread

Tom Carson

yeah on that 8 pin flat connector the turbo has a blue wire for the boost gauge on pin 3 next to green/black on pin 2...that's the only difference there

and also on pin 7 the turbo has 2 black wires both going to 2 separate diagnostic plugs on that same flat connector...no biggie

and pin 5 may have a white/green that goes to a crankcase vent heater that is only on the S2 engine & not the turbo...another no biggie

what else?