Putting a 3.2 into a 73T wiring questions

dmcummins · 12-14-2008, 11:07 AM

I was originally going to put this motor into my 71, but I think it would be easier to put it into my 73 instead. The 73 doesn't have the original motor in it anyway and it already has a 915 trans. Besides I cant get it to start when its cold and I'm sick of reading all the past threads about CIS and cold start problems. I figure I can put carbs on the 2.4 and put that motor into the 71 at a later date.

Ive pulled out the harness and I'm trying to figure out what goes where. The 4 plugs on top of the motor seem obvious.

The three plugs on the side seem to go here, but what is the yellow and brown plug and where does it go?

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Here is another bundle that comes out the back. The brown wires are I assume a ground. But what are the other wires/plugs?

Here is the other end. It looks like I am missing the DME relay and the Altitude module.

dmcummins · 12-14-2008, 11:09 AM

I assume the these go to the starter and maybe the transmission for a electronic spedo?

Grady Clay · 12-14-2008, 11:13 AM

What year and engine type number for the 3.2?
I assume the '73 is actually a '73.5 CIS.

I have a DME manual and the '73.5 only wiring diagram.

Best,
Grady

dmcummins · 12-14-2008, 11:24 AM

I believe it is a 84 Euro. Serial # is 63E06074 Type 930/20.

rs911t · 12-14-2008, 02:10 PM

Unfortunately, I'm out of town so writing this from memory ...

Caution with the 3-connector "panel" on the leftside of the motor. The top one is obvious (I think it's head temperature sensor), but the other 2 can be swapped (the flywheel sensors). Ask me how I know. The engine may start, but will not run when swapped.

The 4-pin connector is for the injectors and connects to the main harness from the DME.

You need the fuel pump relay and altitude sensor. The long, black bundle goes upfront for power.

Yes, the last picture shows the starter and speedo connectors. The latter does you no good unless you have a later 915 and electric speedo in the car.

Mating the 3.2 wire harness to my '72 was pretty simple.

dmcummins · 12-15-2008, 04:31 AM

Here is another loose wire that I have no clue about. Its green with a white strip and is comming out of the bundle that goes to the starter.

dmcummins · 12-15-2008, 02:20 PM

Anyone? I'm going to be pulling the motor soon out of my 73 and I am just trying to get this sorted out.

I think two of these go to the coil, the green and black with the round connectors. But what is the orange thing and the plug behind it?

I'm also concerned about the green wire with the white stripe sticking out from the back of the motor with the starter wires.

Any help would be appreciated.

Thanks,

Mark.

Bobboloo · Bobboloo's Garage

Quote:

Originally Posted by dmcummins

Anyone? I'm going to be pulling the motor soon out of my 73 and I am just trying to get this sorted out.

I think two of these go to the coil, the green and black with the round connectors. But what is the orange thing and the plug behind it?

I'm also concerned about the green wire with the white stripe sticking out from the back of the motor with the starter wires.

Any help would be appreciated.

Thanks,

Mark.

Yes, the green and black are for the coil. The orange thing is for the O2 sensor. You can weld a bung on the exhaust header to hold an 02 sensor.

The green and white wire is for oil press light (idiot light). Since you don't have one with 73' gauges just leave it disconnected. It's redundant of the pressure gauge anyway.

Bobboloo · Bobboloo's Garage

Quote:

Originally Posted by dmcummins

I assume the these go to the starter and maybe the transmission for a electronic spedo?

Backup light (in your hand) and starter wires

Bobboloo · Bobboloo's Garage

The brown and yellow wires in the 2nd from the top picture are for the blower motor for the heater.

dmcummins · 12-15-2008, 04:28 PM

Thanks.

I though that I read that the Euro motor 930/20 did not have an 02 sensor. Would the harness have the provision for one?

I guess I could weld on a bung just to be sure while the motor is out. The orange thing in the bracket is cracked. I cant seem to find it in the parts here. Also I don't see how the 02 sensor would plug into it. Or are you talking about the plug behind the orange thing.

rs911t · 12-15-2008, 05:34 PM

Quote:

I though that I read that the Euro motor 930/20 did not have an 02 sensor. Would the harness have the provision for one?

The car may have been Federalized. This was the case with mine ('86 Euro). It had a US chip and O2 sensor. Get a Euro chip from Steve Wong and leave the O2 sensor disconnected.

dion914-6 · 12-15-2008, 05:58 PM

Try this link:

http://www.pelicanparts.com/MotorCity/marcesq1/

Between this link and the Bentley manual, I put a 3.2 into a 914. Should help with your 911.

Dion

dmcummins · 12-15-2008, 06:23 PM

Quote:

Originally Posted by rs911t

The car may have been Federalized. This was the case with mine ('86 Euro). It had a US chip and O2 sensor. Get a Euro chip from Steve Wong and leave the O2 sensor disconnected.

How would I know what chip I have now?

m_davidson · 12-15-2008, 07:07 PM

The link to Marcesq1, Marc's 3.2L upgrade site, suggested by Dion above, is very useful, but I think Marc may have reversed the two connections to the fuse panel in the trunk. I show the #8 fuse in the center panel labeled the same in the 1988-9, 1977, and, in my case, 1976 wiring diagrams. This suggests the thick black wire to the coil should be connected to the #8 fuse not the #3 fuse. The DME relay #5 pin wire I assume should be wired to a switched source with a similar fuse size as in the '84-'89 cars, probably 25Amp. In my '76 car, the #3 fuse is reserved for power windows, which I don't have: it is not connected to anything on either end in my car. I could, however pick up a switched source and run it through fuse #3 for the relay wire. anybody have suggestions or another source dmcummins and I should look at? / Mel

rs911t · 12-15-2008, 07:42 PM

The chips have a serial number. Steve can tell you. I can look at mine ... but not until next week.

The wiring is different in the later cars. The front connection is different, but I can't remember which I used.

m_davidson · 12-15-2008, 07:45 PM

Referring to the third of dmcummins original pics, I assume you know by now the big round plug looking like a round relay connector, is the test point for engine checking and is inserted in a roughly 1 3/16" hole in the vertical wall of the relay board to the rear of the coil in a 1984-9 car. I believe the ground wires connect to the base of an intake riser on the engine. On my car the pickup wires for the electronic speedo exit the car through the center tunnel next to the shift-coupler and connect to a short harness on the 915 tranny. / Mel

m_davidson · 12-15-2008, 07:55 PM

You're right Greg, thanks. The #3 fuse, middle trunk panel, in the 1977-89 cars is the fuel pump relay, which is the #1 fuse in the rear panel in my '76 car. The wiring diagrams in the Bentley 911 Carrera manual are superb. It doesn't help that Porsche numbers the trunk fuses 1-21, front to rear in their manuals, but 1-3,1-10 and 1-8 in the three separate fuse panels, rear to front.

Mel ('76 & '77 911S, '71 911 T, '72 914-6 conversion)

dmcummins · 12-16-2008, 04:36 AM

Thanks again guy's, I have Marc's page bookmarked. I'm sure I'll be asking more questions along the way. I'm just trying to get as much information as I can before I start. So far I think I got a handle on where most everthing goes in the engine bay now. I'm still alittle foggy on these two things I circled though. If one is for a 02 sensor and I can either delete it or weld in a bung for it. What is the other for and do I need it?

E Sully · E Sully's Garage

I have installed an 86 3.2 in my 73.5T. The orange connector is for the O2 sensor, it is known to fall apart. Pic shows my sensor and its connector. If you are using original trans you will have to cut housing for the flywheel sensors. I suggest you use the newer fuel pump due to differences in pressure. Original is unfused, I used a spare on the fuse panel to feed new pump off the DME relay. Wiring is different for 84 and 86. What are the wiring colors on the other connectors? I can check them in the wiring diagrams.