Fuel pressure regulator yes/no

[Greg]

Am I missing a part? I own a very early 230sl running with a new fuel pump (long one) not original. Car works fine. Even driven for a couple of hours. But there is no fuel pressure regulator fitted after injection pump. I am wondering if the previous owner removed it when fitting new pump or does early pagodas came with no pressure regulators? Thinking of re-fitting one together with an original fuel pump. Any other cars out there running with no fuel pressure regulators?

Thanks
Greg

[travellerdogs]

Apparently the early sl's didn't have that valve looking thing in the fuel line before the injection pump. If that is what you are missing it is really a diaphram housing that takes the pulses out of the fuel system created by the fuel pump. I have a 69 280 and I took mine apart thinking it was a regulator and the rubber diaphram inside was all dried up. That valve is bolted to the motor mount if I remember correctly and one half is a sort of bakelite and the other part is aluminum  and it is bolted together with 4 or 5 small fasteners. I waited for close to 6 months from the dealer for the small rubber and spring and I paid the dealer about $100  for it.  I think Joe Alexander told me that you can run without it. Wish I had of known at the time as |I would have left it as is. I think he told me the early cars didn't have them. I hope that is what you are referring to. It's been a couple years since I had that little episode.

[66andBlue]

The fuel pressure regulator was added starting with engine # 00351 #003351 (manual shift) and engine #000550 (automatic transmission).

[andyburns]

Could anyone with a photo of one of the regulators please post a photo of it in situ.  I dont think my 64 has one but am interested to see where it was located.

[Greg]

Yes, that's the one I mean. So apparently my car came out with no damper. The meaning of it (I think) is that it keeps pressure in the injection pump so that fuel does not run all back to the tank.
I am posting a  few pictures and where it is mounted. There isn't even place where it can be mounted on my engine mounts. So I guess I leave everything as it is.

[ja17]

The fuel regulator on these early engines is a fitting assembly at the IP and on the engine side of the IP. and toward the front. It has the fuel return line connected to it. It can be dis-assembled cleaned and checked.

[Charles 230SL]

I realize this is an old topic but since it specifically relates to my question, thought I'd take the liberty to revive it.

I've got an early 230SL with the original M127 engine #03227. The car had no fuel pressure regulator when I bought it and when Bud's restored the car, the fuel pressure regulator was never mentioned so I just assumed all was correct with my fuel system - that is, until i saw this message string.. 66andBlues's message (below) states that "the fuel pressure regulator was added starting with engine # 00351 (manual shift)". But ja17's message (immediately below) states "the fuel regulator on these early engines is a fitting assembly at the IP and on the engine side of the IP and toward the front. It has the fuel return line connected to it" This is exactly the way my fuel return line is configured (fitting assembly at the IP connected directly to fuel return line).

Since I have M127 engine number 03227, should I have a fuel pressure regulator?
Also, Pagoda Notes Vol 9 No 4, page 5 shows a Fuel Damper was added from engine #550.  I have no fuel damper; am I missing this fuel damper as well? I want my car to be as original as possible and it concerns me that I may have to start shopping for missing parts. thanks for any insight, charles

[Tyler S]

The fuel pressure regulator and the fuel damper are 2 different things. The pressure regulator is no more than the fitting on the return port of the injection pump. Looks just like a regular fitting.  It has a spring and valve built into it. Remove the return line from the injection pump and the pressure regulator (fitting) can be unscrewed. The car will not run without it.

The Damper is the unit with the diaphragm. It is to dampen the pulses created by the injection pump and pressure regulator. If it is missing the car will still run but may have a loud sounding "wirp" while running.

A

[ja17]

Early versions on the M127 engines were a little more than just a fitting. First difference is that it is at the front of the IP, not at the rear as in the later cars. The fitting assembly is much larger, and the fuel return line is a banjo connection of a metal line. The assembly unscrews and a spring and slide valve are inside. Without the fuel regulator, the fuel return is left wide open, causing lower fuel pressure.

[Charles 230SL]

joe/tyler, thanks for the clarification,
my car does in fact have the regulator at the front of the FIP under the banjo connection (see pics). It appears I'm missing both the fuel damper and the mount where it attaches to the left-side engine mount. The damper was missing when Bud's restored the car several years ago and was probably removed by a previous owner decades ago..

[Tyler S]

It may be possible the car never had one. The mount is incorporated into the motor mount arm. It appears your motor mount arm does not have this mounting provision. Its possible the motor mount arm was changed though.

[Charles 230SL]

Hmmmm.. I'm certain these are the original mounts.. perhaps the damper was attached at the front of the mount along with the fuel filter(?).
What's throwing me off is that Pagoda Notes Vol 9 No 4 (pg 5), shows a Fuel Damper being added from engine #550 (I've got engine #003227).

[66andBlue]

Charles,
what is the part number on your engine support arm?
The very early left arm - p/n 127 223 08 04 - did not have the casting to support the damper.
That appeared with p/n 127 223 12 04. For photos see: http://www.sl113.org/forums/index.php?topic=11554.0
Just make sure you don't have the SE arms!

[Charles 230SL]

Al,, I just checked and the p/n on my left arm is 127 223 0804. I think the last two characters of the p/n are "GA" but I can't distinguish them too well.
I guess that settles it, my 230SL/M127 #003227 didn't have a fuel damper. thanks for your help, Charles

[Tyler S]

Charles, Or it did have a damper and it was mounted on a seperate bracket as you suggested and shown in your pic. However, the way the lines are routed, it doesn't look like it would be mounted in the typical place. Perhaps above the fuel filter? The bracket on the page from pagoda notes looks like it has a notch between the 2 large bolt holes that would coincide with the protruding casting angle on the fuel filter housing.
If someone else has an early 230 maybe snap a picture of the setup.

[Tyler S]

My hunch was correct. See Pic.

[66andBlue]

Charles,
my 230SL came about 170 engines later than yours and it also has the early engine support arm without the additional casting. But it does have the regulator and it is mounted as shown in Tyler's photo.

[Charles 230SL]

I guess that settles it, my 230SL/M127 #003227 didn't have a fuel damper. thanks for your help, Charles

On second thought, I guess my 230SL did have a fuel damper afterall..
thanks guys,,Charles

[Charles 230SL]

I was just reading through Pagoda Notes Vol 10, Issue I (April 2016) which shows changes to the 230SL during calendar year 1964. I find it interesting that on page 5 (The MERCEDES Collector excerpt) it shows that a fuel damper was added to the fuel return line from engine -0-3351. Note that Pagoda Notes Vol 9 No 4, page 5 showed a Fuel Damper being added from engine #550. I'm not sure why the engine numbers differ but, based on the Apr 2016 issue my car didn't have the fuel damper.

My car was assembled during Apr 1964 and I have engine #3227 - which preceded the change. Per the Apr 2016 issue, the damper was added in May 1964 beginning at engine #3351.

On second thought, I guess my 230SL did have a fuel damper afterall..

So, on third thought..

[Tyler S]

Being added in 1964 for engine 3351 and above seems to make more sense. The vin numbers are usually somewhat close to the engine numbers so if it was engine #550 it would put that update back to mid 1963. (Which is not calandar year 64)

[66andBlue]

I may have created some of that confusion in my reply #3 when I wrote:
"The fuel pressure regulator was added starting with engine # 00351 (manual shift) and engine #000550 (automatic transmission)."  I should have typed #003351 (manual shift) and have now corrected my earlier post. Sorry!

One can use Engelen's timeline to estimate the VIN for the cars with these engine numbers.
Thus engine #003012 (manual shift) was installed in VIN 003345 (13 Apr 1964) and engine #003380 in VIN 3768 (05 May 1964).
However, for automatic cars the date is known: engine #550 was installed in VIN 003792 (6 May 1964).

Charles what is the VIN of your car?

[Charles 230SL]

I have VIN/chassis# 10-003548 (manual shift)

[ja17]

Charles,

I am not having any luck finding one of these early mounts. Probably one hiding around here somewhere.  You might have to fabricate one.

[Charles 230SL]

thanks Joe, I really appreciate you looking.