1972 350SL Questions - Page 3 - PeachParts Mercedes-Benz Forum

DieselPaul · #31 04-10-2011, 09:34 AM

Right, if I could determine what size I needed exactly, I would have ordered it online in some sweet viton or other baller material, but I need to try them on in person to get a good fit.

DieselPaul · #32 04-11-2011, 06:16 PM

Found an O-ring at lowes, its for a faucet so I doubt its long term petroleum resistance, but I got two so now I have one to measure to order a fuel resistant one online.

However, the car still won't run. It'll start, run for a second then just die. If you crank again you'll hear it fire every couple fractions of a second but not enough. If you wait 10 minutes or so, it'll start right up, run for a second then die.

So, I have a theory. I think my strainer may be clogged. When I had the line off to remove the pump fuel definitely came out, but it wasn't pouring quite like I thought it would. Also the metal disc thing in between the stainer and the pump had some rust in it. My theory is flow from the tank into the pump is limited so when it sits the pump fills up with fuel and it'll start and run until there isn't enough fuel coming in to make adequate pressure for it to run.

Is this possible? The pump was clogged with varnish and gum, I could totally see that metal disc or the strainer also being locked up.

What is the metal disc before the pump called? I'd like to replace it if possible and I'll clean the strainer to start, but I'll eventually replace it.

Graham · #33 04-11-2011, 07:39 PM

Quote:

Originally Posted by DieselPaul

Found an O-ring at lowes, its for a faucet so I doubt its long term petroleum resistance, but I got two so now I have one to measure to order a fuel resistant one online.

However, the car still won't run. It'll start, run for a second then just die. If you crank again you'll hear it fire every couple fractions of a second but not enough. If you wait 10 minutes or so, it'll start right up, run for a second then die.

So, I have a theory. I think my strainer may be clogged. When I had the line off to remove the pump fuel definitely came out, but it wasn't pouring quite like I thought it would. Also the metal disc thing in between the stainer and the pump had some rust in it. My theory is flow from the tank into the pump is limited so when it sits the pump fills up with fuel and it'll start and run until there isn't enough fuel coming in to make adequate pressure for it to run.

Is this possible? The pump was clogged with varnish and gum, I could totally see that metal disc or the strainer also being locked up.

What is the metal disc before the pump called? I'd like to replace it if possible and I'll clean the strainer to start, but I'll eventually replace it.

The metal device between the tank and the pumps is called, I believe, a damper cage (not sure why). It is empty - not sure just what it is really there for - maybe to stop bubbles entering pump?

If you jumper across the fuel pump relay pins 1 & 3, pump should run continuously with key on. You can then check fuel flow rate. To do this disconnect the hose after the fuel damper (the device after the fuel pressure regulator at back of engine) Run hose into a container and measure flow for 30sec - you should collect 1 Litre of gas.

If you do get this flow, your relay may be bad or more likely, there is a bad ground somewhere that causes the relay to drop out once the pump draws a load.

Does sound like you need to completely clean the tank and the strainer.

Pics below: "Damper Cage" (aka fuel damper) and pic of fuel system showing return line to tank (from "other" fuel damper) where fuel flow can be measured.

350SL4spd · #34 04-11-2011, 08:26 PM

Quote:

Originally Posted by DieselPaul

What is the metal disc before the pump called? I'd like to replace it if possible and I'll clean the strainer to start, but I'll eventually replace it.

Called Swirl Can or Fuel Damper. Phil @ Peach Parts can get you the damper but be prepared to shell out $125-150 for it depending if yours has a fuel accumulator or not. Special order from Germany only.

I'm redoing my whole fuel set-up right now on my euro 350 and it's been a nightmare. Phil has been a HUGE help, so I would encourage you to call him and chat with him about it. He can get almost anything on these old cars.

Send/post a pic of your stock set-up if you can.

DieselPaul · #35 04-16-2011, 02:05 PM

Some progress, its taken over a day to drain 4 gallons of gas out of the tank, pretty sure my strainer is toast. I need to go to Sears and buy a socket to take it out.

I took the "bubble" box before the pump off, filled it with brake clean, shook it up and blew compressed air though it. A ton of crap came out of it. Did it a few more times until it was totally clean. I think I saw bits of rubber in it, I think the hose from the strainer to the bubble box is deteriorating internally, not a difficult fix though once I go to put it back together.

Net effect, definitely some flow restrictions between the tank and the pump.

However, I have one major problem. I cannot get into the trunk. No matter which way you turn the key it doesn't open the trunk. If you turn all the way to the left and push, you can feel something sort of brush by, but it doesn't open.

I'd like to be in the trunk, because its my car and I'd like to use it, but also the strainer is slightly offset in the hole in the bottom of the car, and I may have to move the tank to get a socket on it.

And finally my girlfriend and my $2.29 project last night. Are your shoulder belts nasty and faded from the sun? Mine are!
Before

Mixing the dye, used $2.29 Rit dye from Jo-Anns

Submerge you belts, stir them around, then go hit Kroger and buy some chicken!

Finished product

Oh, also, is my car English Red? I can't seem to find a paint code anywhere on the car and I need to order some touch up paint.

rowdie · #36 04-16-2011, 04:48 PM

Is the hose still attached to the strainer?
Paint code is on the body plate on top left of the radiator core support.
Left is body. Right is hard top.

DieselPaul · #37 04-16-2011, 06:21 PM

Yes the hose is still attached to the strainer.

rowdie · #38 04-16-2011, 06:37 PM

19mm Crows Foot and a couple of extensions. Both of the strainers I have done came out with the hose. Does not always happen but you may be lucky like I was.

DieselPaul · #39 04-16-2011, 07:44 PM

Hose came out by itself, damn. I'll have to borrow 3/4 socket set from a friend on Monday

Also the car is paint code 514 carnelian red.

rowdie · #40 04-16-2011, 07:56 PM

Well damn. The nut is either 43 or 46 MM. Can't remember. I don't know anyway to get into the trunk other than to drill out the lock.

Only one reply worked. I usually do better. Sorry.

DieselPaul · #41 04-16-2011, 11:49 PM

Sorry my previous reply was short, it was from my phone at the shop.

No big deal on the strainer, I borrowed a 3/4" drive socket set from a friend to do my 300D and a friends 300SD.

I kind of think I want to pull the tank to clean it and seal it, but I can't get into the trunk. Where is the vacuum line for the lock on the off change the vacuum portion of the lock still functions

DieselPaul · #42 04-19-2011, 09:39 AM

Called the dealer, 514 Carnelian Red touch up paint is no longer available, well darn.

I got the sockets for the tank strainer I should be free wednesday to try to pull it.

deanyel · #43 04-19-2011, 09:49 AM

You wouldn't want to buy paint at the dealer anyway. Any local auto paint store can mix it for you or go to www.paintscratch.com

DieselPaul · #44 04-21-2011, 10:22 AM

Got into the trunk! I read a how to on benz world that said turn an extra 1/8th of a turn and 'don't be shy about it' so I turned like hell and it went. Sadly neither Jimmy Hoffa nor a mountain of coke was in the trunk. Just some ugly floor mats and a lot of rust.

The trunk seal must be bad because base on the delivery sticker under the hood and the license plates in the trunk, the car was in California in 1972, and up until then end of 2002. Yet the floor of the trunk is very rusty. There is also a small hole in the passenger floor, but my suspension and jack points are all okay and no holes in the body, so I'll take it I guess.

I am going to pull the fuel tank tomorrow and clean it out with some KBS aqua kleen, I am not sure if I want to go ahead with the epoxy seal or not, I need to get a look in there and see if its rusty or just cruddy.

Anything I need to know before I try to pull the tank?

meltedpanda · #45 04-22-2011, 11:23 AM

Nice ride, a sister to mine, mine is a very early 72 SL, 541st off the line bought in Europe but and lived there but was always destined to the states. Rebadged as a 450 once here . When I retrofitted the headlight euros on the front the european wiring was evident.
I may have an extra swirll can ,and I have a lot of little dodads left from my rebuild and parts car if I can help