Pagoda SL Group

W113 Pagoda SL Group => Drive train, fuel, suspension, steering & brakes => Topic started by: J. Huber on December 01, 2013, 03:49:34

Title: Fuel issues? related or coincidence
Post by: J. Huber on December 01, 2013, 03:49:34
Well, I was out and about this last week and started noticing a stronger than usual fuel odor. Then I noticed a little puddle of fuel wherever I parked. Today, I was out and looked a little closer and it is coming from right under the fuel pump canister by back axle. Drips when the fuel pump is running.

The car has been running well as usual, and I figured I'd drive home and tomorrow crawl under and see if a hose is split or clamp is loose...

However... on the drive home, at a stop light, the car stumbled and sputtered on take off. Recovered its power and ran fine but did it again after another idling stop.

Here is the question (finally?) -- are the leak and the rough take-off possibly related? Out of curiosity, I checked my dwell and its perfect. Car idles fine. Just that hiccup on acceleration. Any help on this is appreciated!
Title: Re: Fuel issues? related or coincidence
Post by: GGR on December 01, 2013, 09:48:51
Fix the leak first, and then see if the stumbling/sputtering is gone or not.
Title: Re: Fuel issues? related or coincidence
Post by: Cees Klumper on December 01, 2013, 11:49:31
I wouldn't think they are related, unless the drip is caused by some restriction in the fuel lines, and the pump pressure needs to go somewhere. But that is a stretch coming from someone who has never really tinkered with the fuel supply system.
Title: Re: Fuel issues? related or coincidence
Post by: lurtch on December 01, 2013, 17:23:40
Hi James,

A couple of things came to mind:  You should change out the hoses rather than tighten the clamps, and you should also drain the tank and replace the sump screen. I think I recall that your car is an heirloom? If the tank has never been cleaned out I would bet you could fill a tuna can with the rust scale that has accumulated in there.

Larry
Title: Re: Fuel issues? related or coincidence
Post by: mdsalemi on December 01, 2013, 18:47:57
Jim,

What you experienced can most certainly be related.  Been there and done that, a year ago.  Check my posts.

The fuel supply line that goes from the pump at the rear to the metal fuel line running under the car was the problem.  This fuel line is part metal (flare fitting on pump end), part hose (clamp onto hard fuel line) and it failed at the crimp. Air was able to get into the line through the failure point and this caused a bit of rough running, though it took someone familiar with the solid running of the car to detect the difference. I suspect if I let it go much longer the runnability would have gotten worse, but the fuel leakage was a problem.  Doesn't take much fuel to cause a mess.

I changed the fuel line this past May after it sat all winter, and of course the leak went away and runnability improved.

I'd agree with Lurtch, if your tank is original it might be at the end of its service life.
Title: Re: Fuel issues? related or coincidence
Post by: J. Huber on December 02, 2013, 20:43:24
Thanks all. I have not had time to look closely at the hoses yet, but will soon. Mike, I am thinking you are right -- some kind of air getting in.

The tank is original -- but has been dealt with in the past. Same with the fuel lines, but its been 10 years at least. Aren't there a couple screens I could look at to see about debris? Hey Lurtch, pray-tell, what is this sump screen all about...(answer must include step by step instructions.) :D
Title: Re: Fuel issues? related or coincidence
Post by: Jordan on December 05, 2013, 20:19:50
James, I just read a similar story in the latest issue of Hemmings Sport and Exotic.  Guy had a '88 Ferrari 308QC with a small fuel leak.  Appeared to be a faulty hose clamp.  He replaced the clamp.  3 weeks later the car suddenly quit while he was driving.  He pulled over and the car immediately caught fire.  Car subsequently burned to the ground.  A good reason to carry a fire extinquisher.

Of note was to make sure you use the correct clamps (i.e. not worm gear clamps) as well as the correct hose (high pressure hose vs low pressure).  Have you tackled the problem?  Did you replace any of the flexible hoses?