1987 930 Unplugged Connector at Triangle of Death

[SG930]

Recently peaking around rear of engine and saw this connector unplugged. Looked pretty hard but can't determine what this connector goes to. It's in the center of the photo. Thoughts? Engine is modified and has all the usual upgrades: BL WUR, Fabspeed Intercooler, RPM switch, K27, modified fuel head and recently RarlyL8 Street muffler. The muffler is awesome by the way which replaced my B&B dual out muffler.

[SG930]

[quattrorunner]

That looks kinda like the plug that goes to backside of fuel meter?

[gsxrken]

Agreed. Your fuel pumps probably run as soon as the key is on, correct?
Someone unplugged the safety switch on your air meter. Good for troubleshooting but not daily driving.

[porschyard]

Looks like the connector for the frequency valve to me, the harness is to short to be the air flow sensor connector and the connector would be a green or blue color. In your pic I see the longer harness going up to the air flow sensor but a broader pic might help.

Also with all those mods I would suggest bypassing the distributor vacuum advance thermal switch in the breather cover. You can leave the switch in place and either run a single new hose from the throttle valve to the dizzy or just connect the hoses directly together with a hose barb.

That setup is not needed or doing your engine any favors in its stock configuration which restricts ignition timing advance until the switch opens and while it is not very common they do go bad which affects the performance of the engine off boost due to reduced timing advance.

Richard

[gsxrken]

Richard may be right. Here’s a thread with some pictures that should help you figure it out
1986 930 Engine is in, but I have a few loose ends and could use an assist.

[SG930]

My fuel pumps do run with the key is switch on. I will get some better pictures. Thank you.

[SG930]

Here's another connector in another view. Cold start valve? I'll have to get some more pics. Car is running great though!

[SG930]

The air meter sensor is connected in the upper right by the fabspeed air cleaner.

[porschyard]

Originally Posted by SG930

Here's another connector in another view. Cold start valve? I'll have to get some more pics. Car is running great though!

So it appears the air flow sensor is connected and I don’t see a frequency valve, I take it it was removed when the fuel distributor was modified so I am pretty sure that connector was for the frequency valve and no longer needed.

If your pumps are running with KOEO than you have a issue with the air flow sensor contact, wiring or relays. Pumps should not run unless engine is cranking or running unless the air flow sensor connector is unplugged.
Richard

[SG930]

Thank you all! Case closed. The modification must have happened with the fuel head upgrade which I have no documentation on. I have a yellow grounded fuel relay in the engine bay that keeps the pumps on while key on. I suppose it would be safer if that was disabled.

I'm learning about the distributor now. I see 2 vacuum hoses. The most forward hose goes back to onw of the ports in the triangle at the back of the motor. The other hose located at the left rear of the distributor ties into a bunch of valves/hoses that are plugged off. Must be removed air pump stuff?

[porschyard]

Originally Posted by SG930

Thank you all! Case closed. The modification must have happened with the fuel head upgrade which I have no documentation on. I have a yellow grounded fuel relay in the engine bay that keeps the pumps on while key on. I suppose it would be safer if that was disabled.

I'm learning about the distributor now. I see 2 vacuum hoses. The most forward hose goes back to onw of the ports in the triangle at the back of the motor. The other hose located at the left rear of the distributor ties into a bunch of valves/hoses that are plugged off. Must be removed air pump stuff?

The two black vacuum hoses on the thermal switch in the breather cover should only run from the ported vacuum port on the throttle valve to the vacuum advance (rear port) on the ignition distributor and not tied in to anything else. As I mentioned you don’t need that valve in the system anymore but you do need to make sure you are getting a vacuum advance off boost at Rpm. If the distributor vacuum pod is not advancing your off boost performance will suffer (Increased Turbo Lag)

Richard

[SG930]

Here's a pic of the ignition distributor. The left port (rear) goes directly to the thermal vacuum switch. The right (front) (advance?)port goes to the all the old loose piersburg switches. I'll have to check if that one goes to the throttle body port. Probably does as the car runs very well. This is all new to me. So if I go from the advance directly to the throttle body where does the other side go to?

[porschyard]

Originally Posted by SG930

Here's a pic of the ignition distributor. The left port (rear) goes directly to the thermal vacuum switch. The right (front) (advance?)port goes to the all the old loose piersburg switches. I'll have to check if that one goes to the throttle body port. Probably does as the car runs very well. This is all new to me. So if I go from the advance directly to the throttle body where does the other side go to?

They are the same hose, the thermal switch interrupts the vacuum path until the engine temp is warm enough for it to open. You are just going to delete the thermal switch. The frt vacuum port on the pod should go to a vacuum switch which gives a little higher idle when Cold by delaying the vacuum for a short period of time before being electrically opened by the Control unit.

Richard

[SG930]

Looked last night and this is what I saw: Left side(newer hose) goes to the thermal switch and then it goes out of the thermal switch to the throttle body port. The right (older line) goes to disconnected piersberg switches and plugged lines (literally a bolt), likely the removed air injection stuff. I assume this can all be removed since its plugged anyways. I would like to by pass the thermal switch as you mentioned, but do I need to plug the open ends of the thermal switch ports since they open when at temperature (assuming they work)? Thanks for your patience.

[porschyard]

Originally Posted by SG930

Looked last night and this is what I saw: Left side(newer hose) goes to the thermal switch and then it goes out of the thermal switch to the throttle body port. The right (older line) goes to disconnected piersberg switches and plugged lines (literally a bolt), likely the removed air injection stuff. I assume this can all be removed since its plugged anyways. I would like to by pass the thermal switch as you mentioned, but do I need to plug the open ends of the thermal switch ports since they open when at temperature (assuming they work)? Thanks for your patience.

You can leave the thermal switch ports open as they are not tied in to the crankcase ventilation or you can remove the switch and install a shoulder plug with seal ring.
IIRC the plug is a 14x1.5

Richard

[mark houghton]

Originally Posted by porschyard

I would suggest bypassing the distributor vacuum advance thermal switch in the breather cover. You can leave the switch in place and either run a single new hose from the throttle valve to the dizzy or just connect the hoses directly together with a hose barb. Richard

Good description. Was just this morning tracing all the vacuum lines back to that thermal switch. If I recall, on my 1st 930 I had bypassed it. Just one more thing to fail. If I can get my hands back in there I may just bypass this one as well.
You know what they say: "while you're in there..."