Rebuilding fuel distributor

[82DMC12]

Put it back on the car and tested it. Same issue. Ports #1 & #3 feed fuel all the time. Switched hoses and injectors around. Same thing. Whatever lines are on ports #1 & #3 keep spraying.
Trying to think what could be causing this. Seems like the following could be causing fuel to spray out of the injectors on #1 & #3:
1. Injectors are opening at too low of pressure (already disproved this as being the problem)
2. The spring, shim arrangement on these ports is too strong thus holding the port open.
3. There is some sort of solid debris on the face of these two ports holding them open.
4. These ports are somehow damaged (face of port not flat) allowing fuel to pass by when the diaphragm is push up against them.
When I looked at the ports it did look like at least one of them had a notch in it for some reason.
Attachment 67482

I may try one more thing before taking it all apart again. I was thinking of trying the following:
Jump out the fuel pump relay, install hoses without injectors, put hoses in a container, plug in the fuel pump, push the air flow disk all the way down and hold it down for few seconds then release.
My hope, if there is any debris in there it gets washed out and then the flow will close off when the air flow disk is closed.

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It might work. I had two injectors that had sideways spray pattern, did as you did and after a few aggressive pushes of the plate, it blew whatever out and the pattern fixed itself.

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[SupercoolBill]

Are you using a new stainless diaphragm or are you re-using the original one?

New diaphragm. Although the old one looked really good.

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[SupercoolBill]

Well, I give up. We tried after more things with no luck whatsoever. Put on the new fuel distributor hoses without the injectors. Ran the fuel pump and pushed the intake disk all the way down to try to flush a bunch of fuel through the distributor. We did this a few times. Then put empty water bottles on the injector hoses. The same thing happened again. The hose for cylendars #1 and #3 constantly feeding a bunch of fuel. Other hoses feeding little or no fuel.
Took EVERYTHING APART AGAIN. Opened up the fuel distributor AGAIN. Found a tear in o ring on the center tube.
Looked more closely at the metal diaphragm this time. Noticed dimples on it from it contacting the nozzles. As one might expect there were no dimples on #1 & #3. So this verifies what we were thinking. For some reason these two ports are never closing off. My wife measured everything again. She thought she had it figured out. She swapped around some springs. We put everything back together. Put the distributor on the car and hooked EVERYTHING BACK UP AGAIN.
Guess what? The same thing happened. Lines #1 & #3 constantly fed fuel.

We are done...time to get the distributor rebuilt by a professional.

Anyone ever used Special T Auto for a WUR or fuel DISTRIBUTOR? Their prices are a lot less than anywhere else. 20211127_152413.jpg20211127_153452.jpg

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[Bitsyncmaster]

Anyone ever used Special T Auto for a WUR or fuel DISTRIBUTOR? Their prices are a lot less than anywhere else. 20211127_152413.jpg20211127_153452.jpg

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John Hervey passed away some time ago (he owned Special T). Don't know if anyone else has taken over his business.

It sounds like your FD needs a slight surface machining to even out the contact points of those little tubes. I don't know how those tubes could have worn down. Not sure if even a pro rebuilt would fix it.

[painterdave72]

I had mine rebuilt by fuel injection corp in california last year.. quality work and was right around 400 or so .....totally worth it for a part like that..

[SupercoolBill]

Last night I took the FD apart one more time.
I couldn't find anything obvious wrong with it. Used a straight edge to check the depth of the nozzles. All of them appear to be exactly flush with the surface of the cover. The only thing I noticed was that the o ring on cylendar was damaged a bit. This seems to happen everytime even if we lube it before assembly. I don't see how this o ring being damaged would make only two ports feed too much fuel. Instead I would think if anything it would cause a fuel leak. Some of the o-rings on the slit ports look a bit funny, like they went in kind of dry. But non of them are ripped, or not over the little fuel ducts.
At this point I am throwing in the towel on this job.

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Attachment 67546Attachment 67547Attachment 67548Attachment 67549

[SupercoolBill]

Update-
I figured out the issue. The distributor is working perfectly with no leaks.

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[dmcnc]

So what was it?

[82DMC12]

So what was it?

I think he wants us to guess

[SupercoolBill]

So what was it?

Well, I spent a lot of time thinking about how the distributor works, reading what others said, reading information on line. I came to the conclusion that I was looking about and worried about the wrong part of the fuel distributor. I was totally focused on the nozzles, the diaphragm, the springs, and shims. I realized that these thing just "fine tune" how much fuel goes to each injector. Two ports that constantly fed fuel wouldn't be because of anything to do with these parts. It would have to be some sort of an issue with the hollow tube and the ports in the body of the distributor. This made sense because the past several times that we took the distributor apart and put it back together we never pulled the center tube out to check it. So I pulled it out. It looked like perhaps a couple of the o rings didn't stay over the ports when the tube got pushed in during the rebuild.

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