Help Identify

[Srwilliams]

Okay:

Inexperienced trying to put my engine back together. I have a 87 Carrera, 3.2 liter engine. I have got everything back together, of course with a no start (no surprise given my ineptitude). But I do not know what the below pictures reference. Pic 1 is a socket on the drivers side engine wall for a major pronged plug, but for some reason I cannot locate the plug. IS that socket critical to the engine starting (please do not laugh to loud as I am trying to really teach myself, although painstakingly.




Pic 2&3 is the same question. I do not know what the wire/plug go to and is it critical to the engine turning over

[schumicat]

first is for a relay.

second may be 02 sensor which is different than the SC (SC is one pin).

[Srwilliams]

Originally Posted by schumicat

first is for a relay.

second may be 02 sensor which is different than the SC (SC is one pin).

Schumicat:

Once you gave me the lead that Pic 1 is a relay port I was able to hone my research to find that it is supposed be an empty port to serve as a tester port for porsche. So, I am okay that it is empty.

Now if you guys can help me with Pics 1&2 I will be grateful. What does it get plugged into and will it not being plugged up keep the car from starting, as I have a no start that I am trying to trace down

[Synchro Joe]

First pic is for idle speed adjustment, there is not plug attached there. See:85 Carrera Warm Idle Surge and 02 Sensor
Second and third pics look like the Oxygen sensor connector as pointed out. There’s a number of threads on this topic this but this one has some pics:86 oxygen sensor location
In the pics notice the three stacked connectors, these are the sensors top one (white) is for cylinder head temp and lower two are speed and TDI sensors. They all must be connected. The lower two are hopefully marked and should be connected to right sensors. Some other threads on this if you search.

[Srwilliams]

Originally Posted by Synchro Joe

First pic is for idle speed adjustment, there is not plug attached there. See:85 Carrera Warm Idle Surge and 02 Sensor
Second and third pics look like the Oxygen sensor connector as pointed out. There’s a number of threads on this topic this but this one has some pics:86 oxygen sensor location
In the pics notice the three stacked connectors, these are the sensors top one (white) is for cylinder head temp and lower two are speed and TDI sensors. They all must be connected. The lower two are hopefully marked and should be connected to right sensors. Some other threads on this if you search.

Synchro:

I think I am getting it.

Looking at the picture you posted I have the white prong attached to the rail where my reference and speed sensor are located. My car is at a garage about ten miles from me now. But I know all three blocks are in the rail. But is that plug I posted am I to understand that it became detached from the white part of the oxygen sensor that is still on my rail with the rest of the sensors.

That could be a possibility because i have been moving the sensor rail around to work with the injectors. Please let me know if I am in the right direction.

I really need to know---if the oxygen sensor is not connected will that cause a no start that I am now experiencing. I know you probably already answered this but I am so frustrated trying to run down this no start

[gamin]

Synchro Joe has it right. The engine will not start if the speed and reference sensors are reversed. They are identical. Try reversing them. I believe the car will run with the O2 sensor disconnected but on the rich side. I would make sure it is connected. How long have you had the car? Did a PO replace the cat with a pipe and no O2 sensor? Not a great idea if that is the case.

[Synchro Joe]

Pelican Technical Article: 911 Carrera Engine Starting Troubleshooting

Basic non-start checklist posted above. I printed one out & carry it in the car. O2 sensor connects to your DME (see DME info in link above). I am not positive if O2 being disconnected would prevent starting, but does make for rough running. If yours has cat convertor, should have O2 sensor cable running to engine compartment.

[E Sully]

Don't worry, most of the members are more than happy to help. First start can be very nerve wracking.
As you found out the first is a test port, and with a jumper installed is used to set base idle, which on your 1987 will be 880 rpm.
The bottom 2 sensors for the speed and reference sensors can be confusing since they are so similar. Having them reversed would cause a no start, but no damage.
The other connector I can't tell exactly what wire colors are there from the picture. It could be the heater circuit for the O2 sensor, which would not cause a start problem. It is used to bring the O2 sensor up to temperature quicker on cold starts. According to the circuit diagram the wires would be yellow and brown. Your picture seems to show yellow and blue which might mean something different.
Pull a spark plug and ground it while checking for spark while cranking. Full pump only runs while cranking and when the engine sensor detects rotation. Do you smell any gas while trying to start it? If the DME relay is not working you would get a no start, do you feel it click when you turn the ignition key to start?

[Srwilliams]

Sully:

I know I am getting gas at the injectors because that is how I believe I accidentally knocked the back off of the 02 Sensor by getting the injectors straight. One was leaking because when I reinstalled it I had a busted O-ring. So, I fixed that.

I do not believe I mixed up my speed and reference sensors because I am usually quite careful about that. But tomorrow when I go out to the car I will first begin by reversing the wires to see what I get. If that does not check out, I am going to do the spark tests (fire), since I know gas is getting back to the injector rails. I mean gas was really spurtin from the loose injector. So, after I check the two sensors I will start pulling the plug wires and checking for spark as you guys suggest.

Thanks so much

[E Sully]

I just want to get clear, do the injectors actualy open and spray fuel, or just that there is fuel to the injector rail. I have read a few threads were the problem was the connector by the drivers side shock tower that controls the injectors was not properly connected. You can feel the solenoid in the injector clicking when operating properly.

[Srwilliams]

Originally Posted by E Sully

I just want to get clear, do the injectors actualy open and spray fuel, or just that there is fuel to the injector rail. I have read a few threads were the problem was the connector by the drivers side shock tower that controls the injectors was not properly connected. You can feel the solenoid in the injector clicking when operating properly.

Ed:

All I can say is that because the o-ring on the injector was damaged by me and the injector was not properly seated, when I went to turn the engine over gas sprayed out of the whole where the injector was seated, given that the gas pressure blew the injector off. So I knowI am getting gas through the rail and that happened on the drivers side injector rail