I noticed my cranking time was getting very long when the car sat for any length of time. A fuel rail pressure test showed that pressure is leaking away to almost nothing within a few seconds of stopping the engine. Turns out there is a leak from somewhere down at the fuel filter. I haven't had a good look yet, but I suspect it's one of the 2 fuel filter hoses with the crimped collars.

I could cut the collars off and replace the hose, using hose clamps to secure the original fittings. I've seen threads out there where people have done that. Is that safe? I'm leaning towards getting the fittings re-crimped at a hydraulics shop. I just wanted to hear your thoughts on it.

 

See this Pelican thread: http://forums.pelicanparts.com/porsc...ml#post8270982

My posting (#5 down in the thread) has photos of Fuel Injection clamps (NOT worm-gear clamps) being used. There is a link below to an excellent article on using clamps written by a 928 owner; the 928 has about 75 psi fuel pressure whereas the 944 has a low 2.5 bar = 37.5 psi fuel pressure. I replaced the rubber hose with Gates Barricade Fuel Injection hose ( http://www.gates.com/products/automo...ction-hose-mpi ) and clamped mine two or three years ago (see pictures in above link) and all the connections are still tight and dry. Plus with clamps I feel I am more likely to replace the rubber hose more often since it will be quick and easy without having to go to a hydraulic shop. If it were the power steering pump pressure hose with hundreds of p.s.i. pressure I would definitely go to a swaged fitting. Good luck with whatever you decide. Have fun.

See how-to:
http://members.rennlist.com/sharkski...-FuelLines.htm

 

as long as you use high pressure (75+ psi in a turbo fuel rail under load) fuel injection clamps and NOT worm gear clamps, it is safe. my fuel lines under my hood are attatched to both the hard lines and the fail with FI clamps, no worries.

 

Great thanks for the info. I must admit the pressure limit of the hose itself hadn't occurred to me until I read that article. It looks like the Gates Barricade stuff is available locally from O' Reilly so I think I will go this route.

Would the hoses down by the pump/filter see the same pressure as the rail? I would have thought that there would only be 2.5 bar down there, and the pressure added to the regulator from the boost would only be in the rail. Not that I won't be taking every precaution to use the right hose and clamps regardless...just curious.

 

That's crazy considering how much $$ & effort you have invested

 

Lart do you sell those pump/filter lines in the picture? I only see the engine bay hoses on your eBay store.

 

Only if you provide me cores I can do the set in Teflon which will outlast your car

 

Not crazy, I'm using E-85 rated gates barricade hose and clamps rated at 150 PSI working pressure, double clamped on both ends onto factory barbs. While it certainly isnt as beautiful as your SS lines, it is probably safer than the factory 30 year old threaded connections. Keep in mind everyone that various OEM's, Porsche included (on the fuel injected 914's for example) have furnished cars with clamps on their fuel lines. I wish this argument would die...any hydraulics engineer will tell you its totally fine. The average modded 951 will never see more than +- 5 BAR absolute pressure in the lines anyway, and even cheap FI clamps are usually rated at a working pressure of ~7 bar absolute.

That being said, if I wasnt so pragmatic I would pick up a kit from Lart, they are definitely top notch quality.

 

Very nice Lart. Pretty sweet comprehensive kit.

 

so you wont have an excuse I have two sets red/blue ready to ship anywhere in the US for $ 89.99 plus $ 4.99 = total 94.98 shipped that's $15.00 bucks off regular price, remember only two sets for rennlist members cheaper than anybody else.

contact me for paypal information

http://www.ebay.com/itm/1986-1989-Po...item3a94ff6966

 

Only if you had the early fuel lines, I would be all over a set!!

 

Me too Pops! Arnnworks has some stuff for fuel lines too...Might work on our early cars...

 

It's likely the fuel line check valve located at the filter is what failed. I have a new valve sitting on my bench waiting to be installed myself.

 

Actually I just got around to checking closely yesterday and it's definitely the rubber line. It actually seems to have a pinhole that leaks under pressure.

I wanted to do something quickly - even though it only leaks under pressure I'm not happy having it sit there like this. So I picked up some of that Gates Barricade hose and some fuel injection hose clamps today, and I'll cut the fittings off and replace both lines. But I think I'll buy a new set of either OEM or Lart's lines soon for peace of mind.

 

I had a pinhole in one of my filter lines...I cut a 2 inch piece of garden hose down the side, wrapped it around it and put a hose clamp right over where the pinhole was just as a temporary solution to keep my car from pissing fuel on the ground.

I bought all new fuel hoses for the rear of the car (pickup-on) to replace the old hoses, Paragon has them in stock and they have pretty good prices on them if you want to go stock (it lasted 30 years the first time right?)

Good luck,
Ethan