Author Topic: Modified fuel pump.  (Read 11694 times)

stickandrudderman

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Modified fuel pump.
« on: April 25, 2014, 16:03:57 »
The standard fuel pump is old, fragile and expensive.
Where a pragmatic approach is acceptable then a good solution is to fit a more modern pump and hanger from a 124. It's a neat and simple solution and parts can be bought from a breaker easily. Don't worry about the higher pressure provided by the new pump, the fuel pressure regulator takes care of it just fine.
The obstacles are thus:
The inlet pipe to the pump is 15mm whereas the outlet pipe from the tank is 10mm so a reducer is required.
Bizarrely, on the 113 Mercedes elected to use a simple hose clamp fitting at the point where the rubber supply hose from the fuel pump connects to the metal pipe that runs along the floor. Since this is a high(ish) pressure pipe and all other unions along it are compression fittings I prefer to complete the integrity by brazing a fitting on to the pipe. Naturally this means removing the pipe and evacuating all remaining fuel!
Fuel hose. There are many options for this since it’s a custom hose but essentially you need a 12mm banjo at one end and the threaded fitting that you have affixed to the original metal pipe at the other. The hose length from banjo centre to the end of the fitting that joins the original metal pipe is 43cm.
I'll add photos later.

mdsalemi

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Re: Modified fuel pump.
« Reply #1 on: April 25, 2014, 19:08:24 »
I admire the solution.

However, is the "old" OEM fuel pump really "old, fragile and expensive?" I'll give you the expensive, nothing with the Star or Bosch name is cheap. But, with reasonable care, I think these pumps can last about 30-40 years. That's nothing to complain about. It garners complaints, when its end of life appears when in your hands…

And, if you just get an old fuel pump from a 124, then do all this work on it to make it all work, what exactly, is the point? Sounds like you are adding a lot of custom stuff, and who says the 124 pump is any good if its on a junkyard car? You might (not will, but might) just be creating a lot of work, with no net gain.

I like the idea of brazing a fitting on the end of the fuel pipe. Is it possible to find a proper compression fitting, and avoid the brazing? Just a thought…

Michael Salemi
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2023 Ford Maverick Lariat Hybrid "Area 51"
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stickandrudderman

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Re: Modified fuel pump.
« Reply #2 on: April 25, 2014, 21:38:54 »
Personally, I don't use second hand parts, only new, but there are plenty of people out there who are trying to keep their car on the road on a shoestring budget.

jedwards

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Re: Modified fuel pump.
« Reply #3 on: April 27, 2014, 00:36:15 »
Why go to all that effort?
I plan to restore my original pump after it started leaking, ( I do ant to keep the original) but to keep me on the road I installed a WALBRO GCL608 FUEL PUMP for $100 that works perfectly, is plug and play, entirely to spec and is utterly silent.

stickandrudderman

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Re: Modified fuel pump.
« Reply #4 on: April 27, 2014, 11:57:06 »
Quote
Why go to all that effort?

If you mean "to post it here" I'm beginning to wonder that myself!

stickandrudderman

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Re: Modified fuel pump.
« Reply #5 on: June 13, 2014, 13:03:09 »
This is how it looks. I would then fit the plastic cover for completeness.
The advantage is that any future fuel pump failure will be readily fixed by just about any garage as these fuel pumps are so easy to come by.

garymand

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Re: Modified fuel pump.
« Reply #6 on: June 13, 2014, 21:36:15 »
Very nice install.  Are you using the braided stainless covered hose for the higher pressure output? 
Gary
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stickandrudderman

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Re: Modified fuel pump.
« Reply #7 on: June 14, 2014, 07:46:24 »
The stainless braided is a bit OTT in my opinion but i have a local company that makes them so they are just my default "go to" and they are surprisingly inexpensive.

Mike K

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Re: Modified fuel pump.
« Reply #8 on: June 17, 2014, 20:20:11 »
This sounds a lot better than the $960.00 I recently spent on a new Bosch fuel pump for my 280SL!  >:( >:(
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mdsalemi

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Re: Modified fuel pump.
« Reply #9 on: June 18, 2014, 18:06:49 »
"All that effort" referred to NOT the fitting of a $100 Walbro, but the sourcing, removal, cleanup/refurbishment etc. of a used pump from a 124 that was described, plus brazing of fitting(s)
Mike K, you may have spent $960 but you'll be OK for many years if you take care of it!
Michael Salemi
Davidson, North Carolina (Charlotte Area) USA
1969 280SL (USA-Spec)
Signal Red 568G w/Black Leather (Restored)
2023 Ford Maverick Lariat Hybrid "Area 51"
2023 Ford Escape Hybrid
2024 Ford Mustang Mach Ex PEV

stickandrudderman

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Re: Modified fuel pump.
« Reply #10 on: June 18, 2014, 21:00:10 »
The adults among us are free to make choices...............

mdsalemi

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Re: Modified fuel pump.
« Reply #11 on: June 19, 2014, 11:51:18 »
The adults among us are free to make choices...............

Yes, of course…
 
…and then here, at some point in the future, a new owner comes across a completely non-standard part jerry-rigged to a car, done because:

a) the PO (previous owner) had not a clue as to what they were doing, or

b) the shoestring budget thing came in.

Now, in the hands of that PO, or several POs like him, other maladies are "repaired" in a similar fashion. Flexible piping for the random, cheap exhaust system; seats from another brand of car, Japanese radios rammed into the dashboard, way out of spec tire sizes, inappropriate distributors sourced from a junkyard, incorrect trim…

and of course, then, someone comes here trying to get said car running right or looking right and all these issues come to light, and the PO is spoken of in a pejorative voice.

But, as long as an owner knows what they are doing it's all OK.
Michael Salemi
Davidson, North Carolina (Charlotte Area) USA
1969 280SL (USA-Spec)
Signal Red 568G w/Black Leather (Restored)
2023 Ford Maverick Lariat Hybrid "Area 51"
2023 Ford Escape Hybrid
2024 Ford Mustang Mach Ex PEV

gvillayandre

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Re: Modified fuel pump.
« Reply #12 on: July 13, 2014, 17:54:47 »
Hi,

I was on the same possition as you.

Aftermarket or original, and at the end originality won.

Your fitting is quite good, but you are not keeping originality.

There are overhauling kits for short and long stile pump at a price of 100 USD and believe me they works and entertain me a lot.

Now I have original pump working quiet and smooth without any leak.

Up to you!

Travis71280

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Re: Modified fuel pump.
« Reply #13 on: July 13, 2014, 19:09:04 »
I went the aftermarket route. Went with a TREPerformance inline fuel pump a while back for $80 flowing over 255lph. This was after I failed to repair the stock fuel pump and saw how much a new one.  :o Anyways maybe further down the line maybe I'll get a stock one, but this one works flawlessly and I am working on a college budget. Main thing with these pumps is you have to have a high flow pump (255lph+) to keep the injection pump cool. Just my 2 cents.

dirtrack49

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Re: Modified fuel pump.
« Reply #14 on: July 14, 2014, 03:55:33 »
Having recently cleaned up and freed my old long pump, I can only consider myself lucky.

If I had been unable to get the old pump working, I most certainly would have looked for an aftermarket alternative.

Like several parts that I have encountered bringing my 230SL back to life, I find the cost for some, if not most, incredibly over the top when it comes to price. Yes, it is nice that they are available, but somewhere, someone needs to draw the line.

A good example might be the coolant holding tank return hose to the radiator. I believe MBZ wanted over $40 US for it. I replaced it with a high quality US made hose for under $6.00. Certainly, the MBZ hose could hardly be worth the asking price? Even if it were, I could continually replace the US hose several times over before I ever reached the ridiculous price of the OEM hose.

Like many other cars I have dealt with, rather US built or foreign, I will always look for an alternative if I feel the price of the OEM part is well above what it is actually worth.

Tom L.
66 230SL

floatinghat

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Re: Modified fuel pump.
« Reply #15 on: July 17, 2014, 23:27:19 »
Nice solution and to each their own.  I tend to agree with Mike's thinking but if one wants to go through the effort.  The other place I find this type of information helpful is for a drive who might have an issue on the road.  I have my original pump that still works and bought a replacement because I got a "deal".  the only issue with the original is inlet pipe is stuck, but I haven't really tried to get it undone.

That said if done correctly on a budget these can be easy to reverse "mods".

RobSirg

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Re: Modified fuel pump.
« Reply #16 on: August 05, 2014, 01:34:44 »
Each to their own I guess. I now realise what the previous owner did to my new (project) car. I'm currently going through the expensive and tedious process of restoring it back to the original set-up. If only he kept all the parts he removed (as junk) would have $aved me a lot of trouble :(
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Shvegel

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Re: Modified fuel pump.
« Reply #17 on: August 06, 2014, 04:11:59 »
 We seem to forget that unless you have a car that was built and immediately placed in a vacuum there is always a higher horse.  Every single 113 has something that makes it non original even if it is just a battery... Except of course the Submarine of Neckar.
« Last Edit: August 06, 2014, 04:34:34 by Shvegel »

jackhughes81

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Re: Modified fuel pump.
« Reply #18 on: August 07, 2014, 19:39:38 »
I purchased and installed the Walbro GCL508 replacement for my 65 230 when my original pump failed for low pressure.  In the post, I see one of the main concerns is cooling the FI pump. At the 56gph flow, is this enough to cool the FI?  I have an annoying issue now-  The car will run at idle for a long time then suddenly stall after backfire for a minute or so.  If I drive, it does the same after a shorter time.  As it starts to stall, if I jam the accelerator to the floor, it backfires very loudly, but still stalls...  could this be an issue of overheating FI pump?  In addition, upon slow acceleration, the engine hits about 2000rpm then suddenly races to 3000 both when in park and when driving.  I am stumped.  Could this be distributor issue?  The motor sounds like its starving, and backfiring any suggestions???  thanks for any answers or help.  BTW, I just sold the car and would like to solve this prior to delivery..  jack