993turbo

Been doing some searching and it seems I can only find the ''pinout'' for the 79' 14pin engine harness connector.

Does anyone have the pinout for the 90' GT. Its a bit different.

Here is the pinout for the 79':

#1 solid blue. goes to the Alternators B+ terminal
#2 blue/blk. Oil pressure sender unit
#3 blue/yellow. coolant temp sender
#4 blue white. oil pressure sender unit
#5 blue/green. coolant temp sender
#6 blue/brn. engine oil switch
#7 2 red/whites'. WUR and Sup air valve
#8 unused
#9 black. AC and AC pressure switch
#10 blk/yellow dot. Starter to resistor
#11 unused
#12 unused
#13 unused
#14 2 yellows. Large yellow-starter to fuse block; small yellow- to cold start valve

Leon Speed

My own notes for my 89 S4. Colors as far as I could make them out. Didn't trace the wiring diagrams.

1 blue
2 blue or green/black
3 yellow/blue
4 thicker green/brown
5 green/brown
6 dark green
7 red/brown
8 empty
9 black
10 green
11 empty
12 empty
13 brown
14 thick yellow or light brown

BerNard94

Cheers

WallyP

This is what I have for the '90 MY.

#1 blue. E21 to Alternator Terminal B+
#2 blue/black. Oil pressure sensor Terminal WK to E12
#3 blue/yellow. coolant temp sender to E14
#4 blue/white. oil pressure sensor Terminal G to E22
#5 blue/green to coolant temp sender, brown/green to E15
#6 green/blue. engine oil level switch to E13
#7 brown/green. oil pressure sensor Terminal M to E15
#8 unused
#9 black. AC pressure switch to compressor clutch
#10 green to intake temp sensor, brown/blue to fan control unit
#11 unused
#12 unused
#13 brown. intake temp sensor to ground @ MP II
#14 yellow. C12 to starter solenoid

993turbo

Perfect! Thanks a lot! Just what I needed.

:-)

epsylon9mm

Can anyone confirm if PIN #7 ( I have a 1978 ) on the car side of the 14 PIN Connector in the engine compartment requires a switched 12v+ supply ( ie, only provide the 12v+ when the car is supposed to be running, during and after successful starting ) in order to run the fuel pumps?

longleader

This will not help you for a 90' but I found this for a MYs 82'-84'. I wish I could remember where I found it...guess i'm getting old

WallyP

"Can anyone confirm if PIN #7 ( I have a 1978 ) on the car side of the 14 PIN Connector in the engine compartment requires a switched 12v+ supply ( ie, only provide the 12v+ when the car is supposed to be running, during and after successful starting ) in order to run the fuel pumps? "

The car side of Terminal 7 has two red/white wires that feed the Warm-Up Regulator and the Supplementary Air Valve. This terminal is fed by a red/white wire from Q1 (Terminal 1 on Plug Q), which is fed by Terminal 87 on the Fuel Pump Relay.

Terminal 87 on the Fuel Pump Relay also feeds the Fuel Pumps thru Terminal T5 on a red/green wire.

So, Terminal 7 has power at the same time that the fuel pumps do, but the pumps are not fed thru this terminal.

If you are having fuel pump problems, start by checking Fuse #22 and its connections very carefully. Fuse #22 should put power on Terminal 30 in the socket of Relay XVII, the Fuel Pump Relay, when the ignition switch is on.

epsylon9mm

Thanks. This is good info. Let me provide more background.

My motor is currently pulled so I have half of the 14 PIN connector, I was referring to this as the car side ( sorry not the best terminology ). My goal is to test as much of the wiring I can while the motor is out.

I have wired the starter's 12v+ feed directly to the jump terminal in the engine compartment in light of the motor being pulled ( this provides power to the fuse panel in the foot well ).

What I am seeing/hearing when I turn the key are my fuel pumps priming the lines but then they turn off ( after about 1-2 seconds ). What I would like to do is simulate a car start and tell the fuel pumps to stay running. I thought something via the 14 PIN provided a 12v+ switch signal to trip the fuel pump relay. What actually does this?

Alan

The fuel pump relay does it by monitoring the rpm sensor - you do not want to defeat this system - it is there for a very good reason...

Best not to screw with it in case of crispiness...

If you need the fuel pump(s) to run - connect 12v to them temporarily... The only way to test the relay is to send it a pulsed signal that looks like an engine running - the best mechanism is of course a running engine...

Alan

epsylon9mm

Interesting. You learn something new everyday. I did not think that fuel pump relay would operate via PWM signal. I assumed it was a simple on/off switched signal from some source on the engine that routed through the 14 PIN. Makes sense that it would be tied to the RPMs in some way ( ie that is how you know a engine is truely running "rotating" doh ).

If I am understanding things correctly, the PWM tach signal comes from the ignition box on the inner right fender. What other components on the car itself ( not motor ) are driven by the ignition box?

My hopes of testing the fuel pump circuit on the car have been dashed...I need the ignition box to play ball.

Alan

On the early cars 78-84 the relay has the detection mechanism and connects to the ignition controller which passes through the engine rpm sensor pulses.

Cars 85+ the detection of the rpm sensor is done in the EZF/EZK spark controller ECU and controls a standard SPST fuel pump relay via the coil side as a simple on/off signal.

Later cars do not prime before cranking, earlier cars do - priming is better.

Alan

dr bob

You can test the fuel pump circuits on the car by putting a switched jumper in the fuel pump relay socket. Connect to socket pins 30 and 87, turn on the switch, and the pumps should run until you turn the switch off.

Might be worthwhile connecting the fuel supply plumbing to the return line in the engine bay, or be ready for the flow of fuel from the supply side plumbing when the pumps run. It happens quickly, and there's a huge fire risk if not managed perfectly. Maybe do your testing with the car out of the garage and away from the house, charged water hose and a BIG fire extinguisher handy. And easy access to the switch in the jumper to stop the flow of fuel.

epsylon9mm

I have the the fuel lines looped with a fuel pressure regulator in between. I have checked for leaks since the system currently just primes at this point. It has a gauge on it so I can confirm the pressure once the fuel pumps are running and how fast it drops after turning off. It is adjustable past 100 psi. What is the minimum psi the cis system needs to operate the 928?

Landseer

Here's 85/6 USA.