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1980 Porsche 924 Restoration - Finally Coming Together!
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j03k64  



Joined: 26 Jul 2010
Posts: 114
Location: Urbana, Ohio

PostPosted: Wed Oct 05, 2016 7:36 am    Post subject: Reply with quote

There was no way to fix the damage that was done, so I was unfortunately forced to basically finish butchering it. I filed out the connector, checked the E2 to ensure it was okay, made sure it fits tightly on the post and reinforced it with heat shrink as a stand alone wire. I stuck E2 wire on the pin as far as it would go, put the E connector back in the fuse block.

Interestingly, the starter doesn't seem to be intermittent anymore, waiting to see if that returns.

Bright orange/red sparks on the first test; the plug might have been a bit too far from ground point. Second observer noticed white spark on the second or third round of the testing. E2 apparently plays a key role in spark quality?

It would make sense that if E2 was a weak connection, it would cause a yellow spark that would be quenched by fuel spray, causing the engine to flood.

Topping the battery off before attempting to start the car. I'll let you know how it goes! A bit under the weather lately. Cheers!

Fusebox mess (E-block and E2 wire in bottom right).


Finished butchering the E fuse block connector, not happy, but it seems to work.


Modified E fuse block connector and E2 wire.

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Paul  



Joined: 02 Nov 2002
Posts: 9285
Location: Southeast Wisconsin

PostPosted: Wed Oct 05, 2016 7:55 am    Post subject: Reply with quote

One more time: E2 feeds the ignition circuit which includes the coil.
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brian19600  



Joined: 28 Oct 2013
Posts: 375
Location: NJ/CT

PostPosted: Wed Oct 05, 2016 9:55 pm    Post subject: Reply with quote

When you have time, you could always get a connector from a harness in the junkyard. Using a tool, transfer your wires over, except the one. That one, use the one that is in the junkyard connector and splice.
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j03k64  



Joined: 26 Jul 2010
Posts: 114
Location: Urbana, Ohio

PostPosted: Fri Oct 07, 2016 8:43 am    Post subject: Reply with quote

Haha! I caught that Paul. Just clarifying. I hate the referral based wiring diagrams for this car. I'm use to the British fold out schematics where you can directly see how things are linked in the system. I'm 90% fluent in schematic, but that last 10% is irritating as I don't know the specific order things are connected once I hit a referral marker. EG: This bit goes to Part 5, track 11... Okay, right on, but what diagram are they referring to specifically? Any advice on understanding how to read that properly?

Went for start this afternoon with E2 fixed. It tried a bit on the first go, but floods after that; still dead. It seems to crank reliably now and the ignition is more spirited. I pulled the front cylinder plug and plug wire, hooked it directly in the coil and tested for spark; it's bright orange only.

Running low on ideas. I'm going to clean every single ignition wire connection, the entire relay box and let it dry out. Let you know soon...

Brian, they crushed most cars older than ten years old in Ohio during the past few years... starting with German cars
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j03k64  



Joined: 26 Jul 2010
Posts: 114
Location: Urbana, Ohio

PostPosted: Wed Oct 26, 2016 9:40 am    Post subject: Reply with quote

I disconnected, cleaned and dried out every single connection in the ignition circuit multiple times over the past couple weeks. It now has blue/white lightning-grade spark. I'm assuming the incident with dielectric grease , corrosion and other funk played a role in creating that mess.

As suspected, it is indeed a two part issue: spark quality and too much fuel flow.

It's flooding even with proper spark now. If the fuel pump relay is in, it pops on the first revolution, then floods immediately. Pulling the relay and cranking it causes it to act like it might start.

I pulled the fuel distribution head to ensure the main fuel pin isn't stuck or gummed up; it's not. I removed the fuel pressure regulating pin (the bit with the spring, shims, piston and rubber there on the side). It seemed to be 'stuck' or at least well fitted in the hole. It has a small spot with a bit of discoloration on the side of the pin from what appears to be wear. I can take photos if that would help?

If the fuel pressure regulator pin is stuck, I'm assuming it increases the pressure inside of the fuel distro unit, which causes flooding, whereas if it's moving about in there it helps maintain the air to fuel ratio? I'm use to having lack of fuel issues (on both cars), I've never had it send too much fuel to the cylinders before.

The only other thing I can think of would be a dead WUR?
Any thoughts on where to start?
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Paul  



Joined: 02 Nov 2002
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PostPosted: Thu Oct 27, 2016 9:07 am    Post subject: Reply with quote

Pull the injectors and do a volume and pattern test as described in the Haynes manual.

Check the cold start valve and make sure it's shutting down. It should only spray fuel while cranking and even then for only seconds.
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j03k64  



Joined: 26 Jul 2010
Posts: 114
Location: Urbana, Ohio

PostPosted: Sun Oct 30, 2016 9:08 am    Post subject: Reply with quote

Paul,

I put the fuel distributor back on the air box. I didn't tighten the pressure regulation pin as much this time; finger tight and an 1/8 to 1/16th of a turn. I took a photo of it before installing it, you can see the wear spot, but can not feel it.



I also replaced the dead HSV with my spare unit. Does it matter what pin the wires go on? I wouldn't think so as it's a solenoid, but better safe than sorry as those are now unavailable.

Fuel system condition:
-New fuel pump
-New 4oz fuel accumulator
-Newer fuel filter
-Fuel distributor cleaned in an ultrasonic tank
-New fuel injectors

I completed volume/spray pattern test five times to check for variation. Three tests, the ones without leaks or resulting, all passed (one cylinder at 100ml, all other cylinders have 85ml+). Results are are as follows:

* indicates a fuel line leak the distribution head banjo.

The air sensor disk was relatively difficult to pull up and hold with my fingers when the fuel system was pressurized during the above test. Is that level of resistance normal?

More interestingly, if the disk is in neutral position (at the bottom) I still get fuel spray at the injectors. Is that normal? The Haynes manual says "Run the pump and lift the sensor plate slightly (...), so that fuel begins to emerge from the injectors" in the volume test section. This language stood out as it suggests that the injectors should not spray until the air sensor disk is lifted, which is why I'm curious as that might be critical clue to what's going on.

I pulled the CSV. It's pretty gross. It smelled more like the seafoam I sprayed on the bolts, than fresh fuel. I suspended the tip in fuel/carb cleaner for the night.

I also tested the WUR unit. Reads a stable 18.2ohms. Slightly lower than the 20ohms noted in the Haynes manual, but it's not dead/faulty.

Will let you know on the CSV by tomorrow afternoon.

Reference Image:

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Paul  



Joined: 02 Nov 2002
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Location: Southeast Wisconsin

PostPosted: Sun Oct 30, 2016 2:42 pm    Post subject: Reply with quote

You wrote:

"More interestingly, if the disk is in neutral position (at the bottom) I still get fuel spray at the injectors. Is that normal? The Haynes manual says "Run the pump and lift the sensor plate slightly (...), so that fuel begins to emerge from the injectors" in the volume test section. This language stood out as it suggests that the injectors should not spray until the air sensor disk is lifted, which is why I'm curious as that might be critical clue to what's going on. "

Correct no fuel should spray until the plate is lifted. Since you have installed new injectors, the issue most likely is the fuel distributor.
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Polar Silver 02 996TT. "Turbo"
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j03k64  



Joined: 26 Jul 2010
Posts: 114
Location: Urbana, Ohio

PostPosted: Mon Oct 31, 2016 5:02 am    Post subject: Reply with quote

Bummer. I figured that was likely the case. The injectors definitely spray when the plate is not lifted. I know it's strongly frowned upon to disassemble the unit. I take it the general recommendation is to find another unit and pray it works?

So, in short, the CSV acts like a choke, the motor fires and generates sufficient vacuum to run the air plate/fuel distro system. Thus, if the injectors are spraying without the air plate being lifted, it causes massive flooding as air/fuel ratio is grossly incorrect.
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Rasta Monsta  



Joined: 12 Jul 2006
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PostPosted: Mon Oct 31, 2016 5:24 am    Post subject: Reply with quote

You'll get spray at "rest" if the dizzy mixture screw is adjusted too rich.
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Paul  



Joined: 02 Nov 2002
Posts: 9285
Location: Southeast Wisconsin

PostPosted: Mon Oct 31, 2016 6:55 am    Post subject: Reply with quote

Rasta Monsta wrote:
You'll get spray at "rest" if the dizzy mixture screw is adjusted too rich.


Agreed, j03k64 try adjusting it leaner to see if you can get the spraying to stop.
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j03k64  



Joined: 26 Jul 2010
Posts: 114
Location: Urbana, Ohio

PostPosted: Mon Oct 31, 2016 4:36 pm    Post subject: Reply with quote

Paul and Rasta,

I thought of that, but I wasn't sure as to its range of adjustment. I'll have go at changing it tomorrow and see if it will stop spraying at rest and let you know. Thanks for the input!
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Rasta Monsta  



Joined: 12 Jul 2006
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PostPosted: Tue Nov 01, 2016 3:44 am    Post subject: Reply with quote



Ergo, turn mixture screw anticlockwise until you stop getting fuel at injectors, then go 180º further.
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Paul  



Joined: 02 Nov 2002
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PostPosted: Tue Nov 01, 2016 4:45 am    Post subject: Reply with quote

Best to follow the above and test at the loosened fuel connection since the injectors need a minimum amount of pressure before they open.
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j03k64  



Joined: 26 Jul 2010
Posts: 114
Location: Urbana, Ohio

PostPosted: Sun Nov 06, 2016 8:00 am    Post subject: Reply with quote

I finally had a go at adjusting the mixture screw this afternoon. Thanks for the above image Rasta.

I turned it counter-clockwise until it stopped(max lean) and still have spray at the injectors. Fuel emerges slowly from the above injector line port, however, it sprays like hell from the injectors seconds later. Also, the mixture screw doesn't click when you turn it; my 79 is indexed and clicks loudly if you tamper with it.

I take it that means the fuel distro has failed?
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