three vs two fitting fuel accumulator saga

[mike sampsel]

Well since '84 my, '78 SC has been fitted with the two fitting accum.
Added a new one in '06 (two fitting) which cured a hot start issue then.

The PET shows the two fitting accum!

I get that it's supposed to have the three fitting but I do not have the correct hoses to and fittings to get there. "Boxter GT" [hope the ID is correct] builds these hoses but only if I provide the fittings.

Questions:

1.) Is there as easy test for the two fitting accumulator (I've seen Tony's drip test for the three fitting)?
2.) Does someone have the fittings for the bottom of the (3 fitting) fuel accum so I can get a hose built?

My problem is not a hot start one, it's a cold start after sitting for a week. Takes lot's of cranking to get fuel to the injectors. Might be one of three things?

A.) Slow leak in accumulator? (no fuel at the bottom)
B.) Check valve in the Fuel Pump (it's original as best I know)
C.) O-ring bad in the fuel pressure regulator

3.) If I get a three fitting Accum and block the bottom, is it any safer than the two fitting one? But might be easier to test for the next owner.


Issue is not a show stopper, but is annoying and I'm out of "mole-hills" right now.
Here is a picture of my t-fitting cluster flop.

[Flat6pac]

The 3 fitting is a fire prevention if the diaphragm fails in the 3 fitting the fuel is returned to the fuel tank. With the 2 fitting the fuel will drip out the bottom and potentially cause fire.
930.110.514.00

Bruce

[tirwin]

Mike,

I don’t know if this helps or not but I was just recently looking into this as I convert to EFI.

I found Fuelab makes filters with an integrated check valve.

See this link:

https://fuelab.com/product/84800-series-in-line-fuel-filter-with-check-valve/

I was wondering if this would be a cheaper alternative to the factory fuel filter & accumulator. Not as big of an issue for me as I am going to AN fittings. I wonder if Len can make a connector that from the polyamide supply line to an AN -6 or -8 on the inlet of the fuel filter and then -6 or -8 from the outlet to the FD?

First need to determine if this would replace the FA functionality. Given their cost, this may be a cheaper alternative.

Just thinking out loud.

[mike sampsel]

Originally Posted by tirwin

Mike,

I don’t know if this helps or not but I was just recently looking into this as I convert to EFI.

I found Fuelab makes filters with an integrated check valve.

See this link:

https://fuelab.com/product/84800-series-in-line-fuel-filter-with-check-valve/

I was wondering if this would be a cheaper alternative to the factory fuel filter & accumulator. Not as big of an issue for me as I am going to AN fittings. I wonder if Len can make a connector that from the polyamide supply line to an AN -6 or -8 on the inlet of the fuel filter and then -6 or -8 from the outlet to the FD?

First need to determine if this would replace the FA functionality. Given their cost, this may be a cheaper alternative.

Just thinking out loud.

Thanks Tim,

maybe you will have a return line off your three fitting FA for sale sometime then?
Once you go to EFI/ITBs.

"I'm planning to spend the maximum amount possible before I convert to EFI/ITBs ... New airbox, CDI+, three fitting accum, fuel pump for CIS ... [well maybe not]" .

[BoxsterGT]

Hi Mike, I am very willing to help with a solution.

Can you show us a photo of your Return Line assy please?

This is what I made up recently for a 78 911SC, and it has the 3rd Line connection (Left) for the bottom of the Accumulator. We cannot buy these combination fittings (Main Feed and Return) and must Re-Make the customer's original.



Apparently your Return does not have this 3rd Line fitting.

This is on the return low pressure side of the system. I could make up a jumper with a Tee to run a Line/Hose to the Accumulator bottom. Should not cost much. A few fittings and a length of Polyamide tube or E-85 Rated Hose.

Send me a email with the photo of what you have and I will see what can be done.

Len.Cummings at verizon.net

[BoxsterGT]

Mike, I looked at your photo again, and it looks like your Return HAS the 3rd fitting, so I can easily add the Poly Line to the Accumulator.

Just send this to me, its about $25 for Tube & fitting and $25 for my time.

Len

[mike sampsel]

Originally Posted by BoxsterGT

Mike, I looked at your photo again, and it looks like your Return HAS the 3rd fitting, so I can easily add the Poly Line to the Accumulator.

Just send this to me, its about $25 for Tube & fitting and $25 for my time.

Len

Thanks so much Len.

You have an amazing eye, to spot the 3rd fitting off my photo.
When I determine the issue culprit, I'll send you the fitting. Right now it's too darn hot to work on. And without the fitting I'm not sure I can run pressure tests.


I took the screw off the bottom of my accumulator and no fuel came out, so the diaphragm might be okay.

[boyt911sc]

Originally Posted by mike sampsel

Well since '84 my, '78 SC has been fitted with the two fitting accum.
(Edited)"..................

Mike,

You have the connection for the fuel accumulator bottom port as shown in the above picture you posted. All you need is a fuel injection rated hose to connect the fuel accumulator drain port to the main return line. Removed the plugged fuel line in your picture and connect the new return line with the correct fitting for the FA.

Tony

[mike sampsel]

Originally Posted by boyt911sc

Mike,

You have the connection for the fuel accumulator bottom port as shown in the above picture you posted. All you need is a fuel injection rated hose to connect the fuel accumulator drain port to the main return line. Removed the plugged fuel line in your picture and connect the new return line with the correct fitting for the FA.

Tony

thanks Tony,

trying to understand the effort involved before I start this path. From Len's picture:

1.) Blue oval goes to accum
2.) Green circle from the front of the FD?
3.) Red circle goes where?
4.) The part in the green oval screws onto the fuel return line?

And Len, if I decide on this upgrade, I send you the whole thing in the picture from my car and you add the line to tha accum?
If there is an engine drop involved to get to the lines, I will likely stay with the poor two fitting piece accumulator for a while

[boyt911sc]

Originally Posted by mike sampsel

thanks Tony,

trying to understand the effort involved before I start this path. From Len's picture:

1.) Blue oval goes to accum
2.) Green circle from the front of the FD?
3.) Red circle goes where?
4.) The part in the green oval screws onto the fuel return line?

And Len, if I decide on this upgrade, I send you the whole thing in the picture from my car and you add the line to tha accum?
If there is an engine drop involved to get to the lines, I will likely stay with the poor two fitting piece accumulator for a while

Mike,

This is not the correct return fuel line for ‘78~’79 SC but it will work. Right now, your WUR return line goes to the back of the FD. Go check it and I am also an owner of a couple of ‘78 SC’s. The fitting inside green circle is for the FD return line that goes to the backside. Looking very closely at the picture, it looks like an extra nipple was added or welded on for the extra line in green oval.

If you know how to install a Cohline plastic fuel line plus the correct fitting are all you need. Or send it to Len for proper installation.

Tony

[boyt911sc]

Mike,

Found some old return fuel lines for early SC’s in my junk box and a picture of the SC motor.







Tony

[mike sampsel]

Thanks so much for the great pictures Tony. Nice of you to share your knowledge on the subject. Much appreciated. I'll look more closely at the lines.

[mike sampsel]

So it looks like “all” I need to do is disconnect line number 62 from the back of the FD. Then I could get the part out. Would have been easier with the engine out. Doh!

[BoxsterGT]

The Red circle in photo of post #11 above goes to the cold start. Don't recall the customer this was made up for, but I was told it's a 78 SC. US or Euro I don't know.

Len

[mike sampsel]

Originally Posted by BoxsterGT

Mike, I looked at your photo again, and it looks like your Return HAS the 3rd fitting, so I can easily add the Poly Line to the Accumulator.

Just send this to me, its about $25 for Tube & fitting and $25 for my time.

Len

Hi Len, Are you still making lines? If so how can I send the line and payment. You can PM me if you wish. I noticed you PM won't allow any messages.

Mike

[boyt911sc]

Originally Posted by BoxsterGT

The Red circle in photo of post #11 above goes to the cold start. Don't recall the customer this was made up for, but I was told it's a 78 SC. US or Euro I don't know.

Len

Len,

This is an old post and you might not be able to edit your post. The cold start valve is connected to the delivery fuel line and NOT to the return line. I have attached pictures of the OEM return lines.

Tony

[Alan L]

It is unlikely the FA is responsible for the original problem - hard cold start.
If you wish to proceed to 3 port FA be my guest.
But it is unlikely to fix the issue. Other places to look
Alan

[mike sampsel]

Originally Posted by Alan L

It is unlikely the FA is responsible for the original problem - hard cold start.
If you wish to proceed to 3 port FA be my guest.
But it is unlikely to fix the issue. Other places to look
Alan

Alan L; Appreciate the thought. The cold start issue only occurs after a lengthy sit, (starts after 2 - 5 days are usually fine). The hot start issue might be a different problem?

Was thinking of the three fitting for safety and originality plus the hope a new bigger accumulator might help the hot start.

Maybe I need to run pressure tests after the car gets into its hot start funk?

I’ve tested the FD for consistency and all the injectors delivered the same amount of fuel.

I guess it’s possible (long cold start) the CSV runs too long? Flooding the car while the System pressure builds, but starts after a few seconds don’t let the CSV run too long (assumes the TTS is letting the CSV run once engine is warm).

Anyway, will be getting CSV components tested soon.

Any testing ideas are appreciated. Might be best to proceed with a plan once the CSV state is determined.

[Alan L]

You indicated at Post #1 that Hot start was not a problem, but cold start was.
That takes you some place else from the FA.
If Hot start and cold start are both issues then there are many places to look.
Alan