Testing fuel pressure

[Stefan]

I have the instructions from the shop manual on how to check the fuel system pressure and I have some questions:

From Step 2:

"Connect pressure gauge (special tool P 378a) with connecting line (special tool 9559) and connect to test connection."

That's a lot of "connect"s :P

Q1: Is this really a Porsche specific part or might I be able to borrow (or buy) such a thing from the local auto parts store?

From Step 4:

"The seal or sealing ring in the brass closure cap is not exchangeable. It must therefore be used only once."

Q2: Am I correct in assuming that this means I should buy a new cap before attempting to test the fuel pressure?

Q3: Is this part # 993.110.218.01 CAP they are referring to?

[Richard Hamilton]

The manual makes it sound a lot more complicated than it actually is. The only thing is to have the correct fitting for the valve. It's like a Schraeder-type fitting, but there was an adapter in the Snap=On kit that I borrowed from a friend. It's a fairly universal fitting, so I would expect there to ba an adapter in most kits. Rightly or wrongly I re-used the cap. It has a rubber seal in there that looked in good shape in my case, and it is there as a double-safety feature should the valve itself leak.

[pk2]

The manual makes it sound a lot more complicated than it actually is. The only thing is to have the correct fitting for the valve. It's like a Schraeder-type fitting, but there was an adapter in the Snap=On kit that I borrowed from a friend. It's a fairly universal fitting, so I would expect there to ba an adapter in most kits. Rightly or wrongly I re-used the cap. It has a rubber seal in there that looked in good shape in my case, and it is there as a double-safety feature should the valve itself leak.

I'm pretty sure it is a Schraeder valve, As to the o-ring, I'm with you, if it didn't leak before and you didn't ding it... If you did, you can allways go to a Seals Supplier and they'll probably give it to you.

PK

Edited December 4, 2007 by pk2

[Stefan]

Thanks, guys. That's what I thought. Porsche's "special tools" are not always so special.

[Stefan]

Ok, so I bought an Actron CP7818 fuel pressure tester, which has an attachment for Schrader valve fuel test ports. It turns out that the threads on the Porsche are finer than a standard Schrader valve. The attachment that came with the kit screws onto the tire valve fine but the fuel test port seems to be more like 1.25 thread size.

So now I need to find an adapter from standard Schrader to 1.25 (or so). If anyone knows of one, please tell me.

[Stefan]

The plot thickens...it's even worse:

(From http://iecoklahoma.com/adapters.aspx)

"A few of the high-end imports (Porsche, Lamborghini etc) have a proprietary port, often an M14 x 1.5"

I think that I could probably just get the Porsche special part 9559. I think that's just the adapter. Does anyone know where I can get it?

Edited December 13, 2007 by Loren
Fixed link

[Loren]

Your dealer (or Sunset Imports) can order the tool for you. See the part number below.

[Stefan]

Yikes. That part is expensive. It is about $150 and I can't be sure that it will fit my existing tester since I don't have specs for it.

[JFP in PA]

Yikes. That part is expensive. It is about $150 and I can't be sure that it will fit my existing tester since I don't have specs for it.

Everything they sell is expensive, I recently priced a PIWIS system and it cost more (just for the first year) than I paid to add a full bay and lift to my shop...................anything to keep the independents’ out of the loop.............

Edited December 13, 2007 by JFP in PA