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-   -   3.2 Swap wiring Questions. It's in but won't start. (http://forums.pelicanparts.com/porsche-911-technical-forum/270251-3-2-swap-wiring-questions-its-but-wont-start.html)

DonDavis 03-07-2006 08:36 AM

3.2 Swap wiring Questions. It's in but won't start.
 
Lee and Jeff live too far from me to come over daily and bang on me to ge this finished.
Well, I have gotten the engine cranking but it won’t start. No Spark. I borrowed a known good coil from Jeff and have 12v there. I have swapped the Reference and Speed connectors, just in case. Going through the wiring, I think there may be some incorrect connections.

From the DME going forward there are 8 wires.
The ones I certain of are a black/violet (tach), red (battery) and red/green (fuel pump).
There are two 20 gauge wires cut short that I think go to the A/C and are green/yellow and black. These are not used.
A larger black wire is for the coil but I’m not sure which fuse connection is suitable. Switched and cranking 12v.??
Finally, a yellow and a black/grey that are spliced together into a yellow. When I put this one to 12v, I hear the DME Relay actuate. I’m sure this one needs to be a switched 12v but not sure where to put it or if the black should be with it.

I've cranked with the yellow on a constant 12v and with the coil on a constant or switched 12v. No joy.

Another thing is the 14 pin harness. I was able to mostly decipher the ’72 14 pin harness and ID the wires but the 14 pin plug on the ’88 engine is a sticking point for me. My neighbor just got and ’87 Carrera and I pulled his plug and the wire colors match my ‘88. I think I need to pull out the (as per Marc's page) #2 and #8 on the engine side and tape them back. Any other changes here?

My ‘72
1 yellow, AUX Starting relay E&S
2 green, Oil Temp SW
3 green/black, Oil Temp Indicator
4 green/red, Oil Press Ind.
5 green/yellow, Backup light
6 grey, Backup light
7 red/black, ??
8 grey/red, speed switch(MFI)
9 black/violet, Tach?
10 VACANT
11 blue, Alternator
12 VACANT
13 yellow/black, Governor ??
14 red, fuse box III

My ’88 Engine
1 yellow
2 red
3 green/black
4 green/red
5 green/yellow
6 grey/brown
7 VACANT
8 brown/black
9 green/white
10 VACANT
11 blue
12 VACANT
13 yellow/black
14 red

Any insight from you guys??

DW SD 03-07-2006 09:45 AM

I think black on the DME lead needs to go to switched power at the fuse box.

Also, check this link made by Jim Hamilton:
http://www.addictionmotorsports.com/WiringHarness.htm

DonDavis 03-07-2006 07:11 PM

Earlier I pulled back the black tape on the wiring harness that goes to the trunk and found the red/green (fuel pump) wire spliced into a solid green wire. I was told green was the A/C wire and since I don't have A/C, I left it unconnected. We wired the fuel pump directly to a switched supply bypassing the DME. I went by Patrick Motorsports and discussed this with Jim. Turns out I have to go through the DME as the 12v for fuel pump also enables the ignition circuit.

I think I have that squared away now but still wonder if I still need to make changes at the 14 pin harness.

Oh, I'm using fuses 7 and 8 for switched 12v going to the Yellow wire and black wire. Will that be ok?

DW SD 03-08-2006 06:53 AM

I don't know. I thought the yellow wire was tied to the starter solenoid signal?

I believe changes would be necessary at the 14 pin connector. That part is spelled out quite clearly by the link provided.

Doug

DonDavis 03-08-2006 08:02 AM

After speaking with Jim Patrick, I have put the 8 wires from the DME going forward in the following locations. However, it still won't start.

The small black and small green/yellow that are cut short are for A/C and not used.

Yellow and another small black are spliced together. It's a solid yellow forward and from pin 5 of DME and go to fuse 8 "turn signal and back up light".

Large black is from the coil and also goes to fuse 8.

Violet is for the Tach.

Red/green becomes a green and is for the fuel pump. It goes to fuse 3. Nothing else is on this fuse.

Red is from the DME relay pin 6 and it goes straight to battery.

http://forums.pelicanparts.com/uploa...1141836748.jpg

Another thing. My fuel pump runs as soon as I turn the key on. I didn't think it would till I went to startup. :confused:
The pump runs during cranking.

I have a spare DME relay and coil and have tried many different combinations including swapping the reference connector with the speed sensor connector.

It still won't fire.:(

Tyson Schmidt 03-08-2006 08:55 AM

Well, I'm glad to see you got a clicking DME, and a running fuel pump. When we spoke on the phone, it sounded like that would be the problem.

Now I would check grounds. Next, see if you can borrow someone's DME brain. (Actually it would be smarter to swap your brain into their car to see if it runs. Swapping theirs into yours is riskier, since there is the potential of frying their brain if there is a problem with your wiring)

I suppose maybe if the tach wiring were funky, it could kill the coil signal. But the 14 pin connector really shouldn't prevent it from getting spark. It would just prevent the gauges from working, alt. from charging, and the starter from cranking potentially.

DonDavis 03-08-2006 09:06 AM

I have the Violet going to the #2 pin on the tach and the (+) to #5 and (-) to #6. I would have to pull the steering wheel off again to check that but it may be worth it.:(

DW SD 03-08-2006 09:08 AM

can you check that you are getting power to the coil when the ignitiion key is on? Are you getting spark when cranking?

Tyson Schmidt 03-08-2006 09:12 AM

Quote:

Originally posted by DonDavis
I have the Violet going to the #2 pin on the tach and the (+) to #5 and (-) to #6. I would have to pull the steering wheel off again to check that but it may be worth it.:(
Nah, just pull the gauge next to it, and look with a mirror.

It does seem strange that the fuel pump runs with the key on all the time. It should turn on for half a second, then stop. Then start pumping again once the engine cranks.

Have you checked for spark and injector pulse since you got the DME relay working?

Is the 4-pin connector behind the motor plugged in?

DW SD 03-08-2006 09:18 AM

Quote:

Originally posted by Tyson Schmidt
Nah, just pull the gauge next to it, and look with a mirror.

It does seem strange that the fuel pump runs with the key on all the time. It should turn on for half a second, then stop. Then start pumping again once the engine cranks.

Have you checked for spark and injector pulse since you got the DME relay working?

Is the 4-pin connector behind the motor plugged in?

Isn't the tach signal black with a violet stripe (and not just violet)?

Next, is the fuel pump pumping fuel? AND have you done a volume test on it to test it?

Doug

Tripster 03-08-2006 10:28 AM

Don,
if you do a search on my name you should find alot of what you are looking for as I just went thru alot of wiring of my 84 Carrera. if you dont find what your looking for PM me and I will give you info I have found elsewhere not posted on this forum.
Mark

78-911SC 03-08-2006 10:36 AM

I'm not sure I can help but I'm going through the same thing. My harness had the dme relay plug cut out with a few other wires. Here is what I have.
grn/yel is for A/C going to pin29
yel is ignition switch going to pin 4
2 blk -both on mine tested out to pins 21 and 11 for tach.
The large blk goes from coil to fuse 8 and out of fuse 8 to pin 86 on the dme relay. The large grn goes from the coil to pin 1.
The red/grn goes from the dme relay pin 87b to fuse 3 and out of fuse 3 as a red to the fuel pump. The other side of the fuel pump is brn and goes to the carrier plate ground screw.
Pin 30 on the dme relay is red and goes to the battery.
Make sure like Tyson and Doug said you have spark and the 4 pin connector behind the engine is plugged in. Good luck I'll be were you are in a few weeks.

DonDavis 03-08-2006 01:07 PM

Quote:

Originally posted by Tyson Schmidt
Have you checked for spark and injector pulse since you got the DME relay working?

Is the 4-pin connector behind the motor plugged in?

Still no spark. How do I check for injector pulse? Yes, the 4 pin is plugged in and I verified correct wire locations.

Quote:

Originally posted by DW SD
Isn't the tach signal black with a violet stripe (and not just violet)?

Next, is the fuel pump pumping fuel? AND have you done a volume test on it to test it?

Doug

Yes, the Tach wire is black/violet but on my harness its spliced to a solid violet. No volume check on fuel but I know I'm moving gas. I had some leaks!! :eek: They're all fixed now.

Which side of the fuse panel should I make the connections? Right or left. Remember, my car is a '72 and the panel is mounted vertical. Marc's page refers to a '77 panel and its horizontal.

DonDavis 03-08-2006 01:35 PM

Here's something interesting.
Key on, my turn signals do not work at all.
Key off, they come on but no blink.
No brake lights at all.

hmmm, the thought plickens!:confused:

Shuie 03-08-2006 06:12 PM

Re: 3.2 Swap wiring Questions. It's in but won't start.
 
Quote:

Originally posted by DonDavis
I have swapped the Reference and Speed connectors, just in case.
Are you sure the spacing between the sensor and the flywheel teeth is correct? Ive seen several times in posts here where someone has moved these wires and then hooked them back up with incorrect spacing and had ignition issues. One of the technical bibles (I think its the Bentley) has a typo concerning this measurement so you cant rely on that either. I think the correct measurement is 0.8 mm.

Also, did you keep your relay panel? Or did you just hook the engine wiring harness to the main chassis harness?

heres the 3.2 from Marqesqs site

Quote:

This is the 14 Pin Female on the 3.2 engine. Pin numbers are divided odd on top and even on the bottom. The pin assignments are as follows:

1. yellow - starter Kl.50
2. red - source from alternator Kl.30 ( or B+ )
3. green/black - Oil temperature Instrument
4. green/red - Oil pressure Instrument
5. red/green - from ignition.( Kl.15 ) to backup light switch
6. gray/brown - backup light switch to lights
7. free
8. brown/black - temp switch for fresh air blower
9. green/white - Oil pressure idiot light
10. free
11. blue - alternator control light Kl.61 ( or D+ )
12. free
13. black/yellow - power source for fresh air blower
14. red - source from alternator Kl.30 or B+

and a 2.7 RS pinout from an old Roland Kuntz post. This should be almost identical to a 2.4 MFI from '72-'73

Quote:


T 14 2,7 ( 73 )

1 yellow / starter Kl.50
2 green / only used with sportomatic runs behind
the instrument for the overheat idiot light
3 green - black / Oiltemperature Instrument
4 green - red / Oiltpressure Instrument
5 green - yellow ( depends on year ) / from ign. to backuplightswitch
6 gray - black ( depends on year ) / backuplightswitch to lights
7 black/red / Coldstartenrichment temp switch
8 white/red / MFI stop selenoid
9 black - purple / to tach
10
11 blue / alternator control light Kl.61 ( or D+ )
12 brown / to Regulator D-
13 black / to Regulator DF
14 red / source from alternator 30 or B+


brown - white / Sportomatic power source
blue - yellow / Sportomatic shift lever contact
yellow - black / Fresh air blower
red - white / to MFI/CIS and fuelpumprelay


DonDavis 03-08-2006 07:21 PM

Good stuff. Sherman, I never messed w/sensors. Just the connectors over left intake. Its a good thing to chk tho.
I really think the problem is within the 14 pin conn.
Doug, the pinout doesn't specify how he made those work. Move which wires to where? Looks like his harness just jumpers. I'll look at it more.

Shuie 03-08-2006 07:45 PM

Here's how I was going to map my chassis wiring harness to the engine wiring harness on my 3.2.

http://forums.pelicanparts.com/uploa...1141879398.jpg

Most of the pins are already aligned. I was planning to change engine harness over to a 14 pin male connector, move pin 9 to slot 2, and then tie off the wires that would normally be in pins 2, 7, 8, 10, 12, 13. After that id just plug the engine harness into the unmodified chassis harness and put the relay panel in a box for safe keeping.

Where did you put the red fuel pump relay? I have a 5 pin relay socket in my engine bay from the DME harness thats confusing me. It can only be for a fuel pump relay, but I would have thought it would have been in the front of a carrera :confused:

DW SD 03-08-2006 07:51 PM

Quote:

Originally posted by DonDavis
Good stuff. Sherman, I never messed w/sensors. Just the connectors over left intake. Its a good thing to chk tho.
I really think the problem is within the 14 pin conn.
Doug, the pinout doesn't specify how he made those work. Move which wires to where? Looks like his harness just jumpers. I'll look at it more.

Don,
He made a conversion harness which adapts one set to the other. You can move the pins around to suit, too.

Doug


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