FD Pressure Regulator Parts

[tito911s]

I know that Pelican offers a full kit to replace pressure regulator - but for those who simply want to replace the offending parts (o-rings, etc.), what parts are suggested to be replaced?

For example, on my 1981 engine, and thanks to Tony and other CIS gurus, it seems like there are 2-3 o-rings that need replacing. But, for the life of me, I cannot find anywhere that provides the specific size of the o-rings or what type to use. And do only the o-rings need replacing?

Thanks all.

[john walker's workshop]

If they're not torn, they're probably ok. Just blow out the valve and reassemble and recheck pressures.

[boyt911sc]

Eric,

PM me your address and will mail a few o-rings for your primary pressure regulator. There are two (2) different tiny o-rings you need for the PPR.

Tony

[scary driving]

I used the precision machinery kit they sell on ebay. Bought the alignment tools tool. Has every single oring the distributor uses.

[tito911s]

John, Tony, et al --

Thank you for response. Based on all my testing, I believe this will solve my problem!

Cheers.

[boyt911sc]

Eric,

Your primrary pressure regulator for FD-077 needs only one (1) o-ring not 2 as I mentioned earlier. I will send it as priority mail by tomorrow morning.



Hope this would correct your warm starting problem. Keep us posted.

Tony

[john walker's workshop]

There's one on the piston too. That one tends to trap debris and cause leak down.

[boyt911sc]

Originally Posted by john walker's workshop

There's one on the piston too. That one tends to trap debris and cause leak down.

John,

You just saved me from another blunder. I knew there were two (2) o-rings needed for the primary valve but when I pulled the PPV, I inadvertently left the piston inside the FD and was baffled to see only one (1). A senior moment.......knew there were 2.



Glad you mentioned the piston. Otherwise, I would be sending the the envelope with just one instead of two different o-rings. Well, this was not first time you have rescued me from my predicaments. Thank you.

Tony

[tito911s]

Thank you gentlemen. Pulled regulator today and, while I'm no expert, things look okay. The o-ring closer to the bolt head was a little loose . . but the other one felt tight.






Here's a review of what I have attempted to do to fix my warm-start issue. Conducted Control pressure, cold pressure, warm pressure and residual pressure.

Car: 1976 911 with 1981 SC engine. WUR: 090 FD: 0 438 100 077

Ambient temperature is 65-70F/~18C:

Control pressure jumped to 4 bar and settled at 1.5 bar.

Cold pressure settled at 2 bar.

Warm pressures as follows:

2.5 bar @ 45 seconds
3 bar @ 90 seconds
3.5 bar @ 3 min
3.6 bar at ~ 4 minutes

Residual pressures as follows:

Shut off FP and gauge fell immediately to 2.7 bar

1 minute after FP shut off @ 2.5 bar
5 minutes @ 1.9 bar
10 minutes @ 1.8 bar
30 minutes @ 1.7 bar
60 minutes @ 1.3 bar
90 minutes @ .8 bar

Checked accumulator and fuel pump check valve, with Tony's help and they checked ok.

Next, I'm going to get some techron and drive the car as much as I can this week (weather allowing here). Last thing I can think of is injectors leaking...

[tito911s]

double post - delete post.

[tito911s]

...

[tito911s]

First, thanks to Tony for o-rings for primary pressure regulator. Carb cleaned the bits and used some compressed air to blow out hole in fuel distributor.

Starts cold great (always has). Let it run for 15-20 minutes. Shut off. Restart immediately. Fires and holds idle great. Turn off and wait 5-10 minutes. Try to start, and it immediately fires/dies. Crank for 3-5 seconds and fires. Stumbles.

My warm start problem persists. The only thing I have not checked are the injectors.

Before I pull and flow/leak test, I'm thinking drive the car to 1/4 tank. Put techron (or similar, any suggestions?) drive it till close to empty. Repeat.

[Bucketlist]

Not to hijack but a suggestion, an old story, and a question.....

First the suggestion: double check for vacuum leaks. After several tests I found a smoke test to be most successful.

Story.... when I bought my SC Turbo I found the PO had removed the piston from the Pressure regulator and stretched the spring to compensate (along with a few other blunders). I ordered the new regulator and was disappointed that it did not come with a new spring. I wanted to replace the spring but couldn't find a source.

Question.....any ideas on the source of a new spring?
Its only been 8 years.....