Fuel Damper Question

Tx951Dude · 12-11-2004, 08:53 PM

Okay, I was able to get my fuel damper off but now I'm having a very difficult time getting the new one connected. The problem is with the small fuel line going from the damper to the fuel rail. I was able to get the line off without removing the fuel rail but re-connecting it has proven to be a real challenge. There isn't much clearance between the banjo bolt fitting and the valve cover and the number one fuel injector plumbing. Is there a trick to connecting it or will I have to remove the fuel rail? If I'm going to do that I may as well replace my injectors as well.

Any help on this would be great!

Lawrence Coppari · 12-13-2004, 03:37 AM

New injectors are about 100 bucks each. How do you know there is something wrong with them? They can be ultrasonically cleaned for 1/4 the price of new ones. Had mine done recently, and I'm quite pleased with the results.

Sorry, never had the fuel damper off on my car. Removing the rail is no big deal. I take an air hose and blow off grit around fuel injector where it sticks in intake. Then I squirt some transmission fluid around the base of the injector to facilitate removal. Then pull them straight out.

Tx951Dude · 12-13-2004, 06:40 AM

I don't plan on purchasing new injectors should I replace them. I will purchase rebuilt ones from 944online for $40 each with exchange. I don't have an air compressor handy or the time to rebuild them myself, or I would. I've just heard that after 100,000 miles injectors need to be either replaced or rebuilt to maintain performance.

It seems that this entire mess could have been avoided by doing a bit of research on my part, lol. I believe that I could have had the line and damper replaced under a Porsche technical service bulletin with only the cost of the damper not being covered. My local dealer is checking into it today. If so I'll just have the car towed to the shop and have the guys who get paid to work on these babies fix it.

Tx951Dude · 12-14-2004, 12:48 PM

Dang it! Figures that the TSB was performed on my car back in 1990!!! Okay, looks like I'll be re-connecting the fuel line after all. How difficult is it to access the fuel pump on the 951? Is it required to remove the pass. side front wheel? Can it be reached from underneath the car? I would really like to replace the old lines between the pump and FPR/Damper connections. Is there a quick and easy way?

Tx951Dude · 12-16-2004, 07:29 AM

Okay, guess my post is dying

Well, I am an idiot now, it's confirmed! I suppose everyone who has read this post was wondering what the heck I was talking about with the fuel damper to fuel rail line attachment problem. Seems that I was trying to run the line UNDER the fuel rail bracket that's attached to the valve cover and not OVER it, as designed. No wonder it was binding! It took a bit of Net research and finding photos of stock 951 engines to discover the mistake on my part. Anyway, once I did manage to get the line under the bracket and attached to both fittings I ended up with a massive leak in the line. Of course as soon as I began to turn the ignition, fuel began spewing all over the top of the engine. Fortunately for me, the engine would not start and I avoided a fire and/or explosion! I ordered the braided lines from Lindsey Racing yesterday and hope to replace all of them this weekend.

nize · nize's Garage

wow, let us know how it goes.

you also might want to try posing your questions on rennlist.

Tx951Dude · 12-21-2004, 10:27 AM

Successfully replaced the damper and my car is running again! I have not however replaced the two lines leading from the damper and FPR which run down into the inner fender wall. The guy at Lindsey told me that I would need to remove the wheel and remove about ten screws that hold the inner fender to the car in order to access the fuel pump and lines. What a pain that will be! It also seems that the old lines will have to be cut before replacing with the new ones? If that is indeed the case can I not cut these lines higher up where they are accessible inside the engine bay instead?

nize · nize's Garage

maybe cutting the lines higher up defeats the purpose of replacing the lines to begin with?

Tx951Dude · 12-21-2004, 10:54 AM

I agree totally with that point. I suppose that I should have qualified my question a bit better. Why should I be cutting the lines in the first place? Shouldn't they just unscrew by the fitting instead? Just how do the lines connect to the pump? Since I am unable to see this connection with taking the fender apart I would like to at least know, lol.

nize · nize's Garage

this is an older 944, but it might be similar;

http://www.pelicanparts.com/944/944_parts/944_83-85/Pic13.jpg

do you not have the shop manual on cd? i'll see if i can dig it up if i remember later.

nize · nize's Garage

here's the shop manual diagram. i think what you can do is look up the actual part that the line attaches to, and see what the connections look like;

Karl2bdc · 12-21-2004, 10:14 PM

I am a little confused, why do you want to replace the hard metal lines that run all the way back to the fuel pump, which is mounted underneath the tank? The fuel lines everyone talks about replacing are the rubber lines that run down from the FPR and Damper to the hardlines right at the passenger fender. If you want to just replace those, you can cut off the crimps and the remove the rubber hoses and attach new ones without removing anything in the fenderwell. Seems odd to replace the hard metal lines that run under the car. There is also a short 6 inch rubber line that connects to the fuel filter back by the tank that should be replaced as well. It has screw fittings on both ends.

Tx951Dude · 01-20-2005, 12:00 PM

Thanks Karl, sorry I'm just now posting a reply to your question about fuel line replacement. Actually I am talking about the two lines running from the FPR and damper and disappear into the fender. My question is how difficult is it going to be to replace those lines. Will I be able to access them simply by removing the front wheel or will I need to remove additional parts once that has been moved out of the way. I suppose that the short line running from the tank to the fuel pump must also require replacement.

Britwrench · 01-20-2005, 01:52 PM

For repair shops it's a liability issue. Porsche installed the fuel lines on most 944 models as a crimped assembly of front to rear lines. The replacement parts come in two pieces; the front and rear with a connector. As the original parts are crimped the new ones should be as Porsche designed. Installing the hoses with clamps is fine if you are doing it to your own vehicle but for shops the possiblity of being sued for a fire or similar is too much of a risk unless the customer would sign a disclaimer notice and even then it's still a risk for the shop. New flexible lines can be crimped on as the original type sleeves and correct hoses are available. But not through Porsche.

Karl2bdc · 01-20-2005, 06:29 PM

Um, the lines that you need to replace, can be cut off the hard lines from inside the engine bay. Take a dremel, cut the crimp (I cut an L shape in the crimp, then you can bend the crimp back with a pliers and the line will come off, this avoids cutting too far into the line and encountering fuel). Attach the new lines with fittings, and you are set. You dont need to do anything inside the fenderwell.

Karl2bdc · 01-20-2005, 06:31 PM

Oops sorry, in the above picture by the passenger fender, you can see where the fuel lines end (you can just see the hose clamp on the top line in the picture), so it is all accessable from the inside. Maybe lindsey lines are different or something, i used Rennbay fuel lines.

Tx951Dude · 02-25-2005, 11:32 AM

Okay, I suppose I'll stop by our local Ruf shop and let those guys tell me the easiest way to replace the lines. Lindsey did send along a free mini tube cutter with my new lines so I should just use it to cut the lines and slide the new braided lines over the existing tubing, I'm to assume? What was the mention of cutting the lines too far and encountering fuel? Won't that happen anyway even after I've de-pressurized the system, once I cut into the lines? BTW, replacing the old damper didn’t resolve my hot start issue. The problem has occurred a few times now even when it’s cool outside!! I’m almost sure it must be a leaking injector at this point so that’ll be the next project after I replace the lines.

Karl2bdc · 02-25-2005, 04:20 PM

You can cut the crimps off the end of the fuel lines, without cutting through the rubber hose. Then the rubber hose will pull off the metal hard line that runs back to the tank. Think of it like this.... they used non removable metal crimps in place of hose clamps. To get the crimp off, you have to cut it off. Rennbay lines will use hose clamps for the new lines.