1968 (w)110 230 fuel pump for M180 engine? - PeachParts Mercedes-Benz Forum

chris1968230110 · #1 09-30-2008, 12:32 AM

Hi, I'm to pick up a 1968 (w)110 230 from Seattle and bring it home to Vancouver BC.

The problem is the fuel pump in the car is bad. The electric one and mechanical are both toast.

I have a new mechanical fuel pump for a 1966 200, part 1150900150.

Will this pump work?

They appear to mount differently. The bad 230 pump mounts down and my 200 pump mounts to the side.

I really don't want to drive 150 miles one way and come back home empty handed.

Is it easy to make an electrical pump work?

What do I attach it to?

Is there any benz shops in Seattle open Saturday?

Thanks guys for any help.

chris, Vancouver, BC

wbain5280 · #2 09-30-2008, 12:46 AM

What electric fuel pump?

chris1968230110 · #3 09-30-2008, 03:00 AM

Funny, I thought I configured email notification.

This car (and my current '66 200) had generic electric pumps installed after the mechanical ones crapped out (diaphrams old). The electric pumps broke down as well.

I got the mech pump 1150900150 working on my '66 very quickly and am parting that car out and want to use that pump in the 230.

However, the pump in the 230 installs downward, and in my car installs sideways...

Though I think the old one installed down in my car too but I think it had a base to install downward...

How hard would it be to install the electrics on a electric pump?

The electric pump in the 230 got its power coming from the side of one of the Zenith carbs, from the auto choke coil I think. I didn't check to see if that works....

chris1968230110 · #4 09-30-2008, 03:02 AM

Hi, I'm to pick up a 1968 (w)110 230 from Seattle and bring it home to Vancouver BC.

The problem is the fuel pump in the car is bad. The electric one and mechanical are both toast.

I have a new mechanical fuel pump for a 1966 200, part 1150900150.

Will this pump work?

They appear to mount differently. The bad 230 pump mounts down and my 200 pump mounts to the side.

I really don't want to drive 150 miles one way and come back home empty handed.

Is it easy to make an electrical pump work?

What do I attach it to electrically?

Is there any benz shops in Seattle open Saturday?

Thanks guys for any help.

chris, Vancouver, BC

wbain5280 · #5 09-30-2008, 03:41 AM

The two blocks are the same design and use the same type of fuel pump. It bolts to the side of the engine at the front because it's driven off a lobe on the oil pump. Excess fuel is routed back to the tank.

If someone added an electric pump, then take the power from the ignition switch and use a fuse to protect it. Add a relay as well so the load is minimal.

The electrical system on the car is very basic.

todds · #6 09-30-2008, 10:05 AM

A cheap electric pump for a carb application will work fine if you are just looking to get it running. For longer term and more reliablility look into carter electric pumps. They are widely available. I bought one for my 230S and it's a good quality, solid "piece of kit" as the english say...

chris1968230110 · #7 09-30-2008, 03:33 PM

Guys, thank you very much for your replies.

So I have two options then; put on a new mechanical pump, the part# I mentioned or a temporary one as a contingency to drive 150 miles home to Vancouver.

However, while mech pumps appear to be the same, the pump in the 230 installs downward, and in my car installs sideways...

Does the 230 have a base that is removed? I can post pics of both pumps if that helps.

What about the temporary electric solution? How would I protect it with a fuse? And would I have to immediately shut it off once the engine shuts off? I guess there wouldn't be a over flow problem as excess fuel would return via the fuel return line?

Thanks a lot!

cp

Mike D · #8 09-30-2008, 04:04 PM

If it's just a temporary pump to get you home then use the 12V hot feed to the ballast resistor (not the coil side). Stick a 5 amp inline fuse in the wire leading to the pump. It will only engage when the ignition is in the "run" position.

chris1968230110 · #9 09-30-2008, 05:04 PM

Mike, thank you very much.

The bad electric pump was connected to a connection on the Zenith carb (similar pictured below), where the coil I guess would be, as I circles in the pic below:

http://98.130.96.83/ze_35-40inat_opel_commodor_640.jpg

Is that the correct place to connect it to?

I posted to 6 or 7 busy Mercedes forums (fora?) and YOU GUYS ARE THE ONLY ONES TO PROVIDE MEANINGFUL HELP!! =))

Thank you!!

cp

Mike D · #10 10-01-2008, 09:22 AM

The coil would be my second option but I generally find someone has messed with the wiring and rendered it useless. Some of the coil electrics are tied to a temp sensor which trips a relay when it reaches operating temp so it kills the power.

Mark DiSilvestro · #11 10-01-2008, 09:26 AM

Quote:

Originally Posted by chris1968230110

Mike, thank you very much.

The bad electric pump was connected to a connection on the Zenith carb (similar pictured below), where the coil I guess would be, as I circles in the pic below:

http://98.130.96.83/ze_35-40inat_opel_commodor_640.jpg

Is that the correct place to connect it to?

I posted to 6 or 7 busy Mercedes forums (fora?) and YOU GUYS ARE THE ONLY ONES TO PROVIDE MEANINGFUL HELP!! =))

Thank you!!

cp

Your picture shows the +12 volt connection to the automatic choke heater. Normally, I wouldn't connect an electric fuelpump there, but it my be ok just to get the car home, assuming that the failed electric pump didn't blow the circuit and kill power to the choke. With the ignition on, check the choke wiring for power with a voltmeter or 12 volt test light.
Or, as someone suggested, you could try wiring a pump-fuse to the ignition-coil circuit.
Otherwise, I would prefer wiring an inline fuse to the ignition-switched strip at the back of the fusebox. Your ignition switch should be able to handle the added electrical load of the fuelpump without a relay.

As for using a relay, one downside of changing from a mechanical to an electric fuelpump is that, in case of an accident, a broken fuel line will allow the pump to pump gas as long as the ignition is left on.
Auto manufacturers used to provide some type of fail-safe relay wired to the oil-pressure switch or charging circuit to kill power to a factory-installed electric pump if the engine died with the key on. Today, cars do this through the engine's computer.

As for the OE mechanical pumps, as I recall until the early '70s, Mercedes used a fuelpump mounted to the block with a right-angle adapter. Around 1971 or '72, they changed to one mounted directly to the block without the adapter.

If your 200 engine had a later-style direct mounted pump installed, it will probably work on the 230, but check the mounting and actuating plunger on both engine blocks to be certain. If the direct-mount pump off your 200 has a thick plastic spacer, you will probably need to transfer that to the 230. And take the 200 pump mounting-bolts with you in case they're a dufferent length as well.

Happy Motoring, Mark

chris1968230110 · #12 10-01-2008, 12:34 PM

Wow Mike, thank you!

I'm printing this all out.

I'm going to try both solutions. The mechanical pump was quite easy to install so I'll try it first.

Yes, there was a spacer, and I do think there was a right angle adapter...

Is a proper gasket very important for the mech pump or can I use any gasket paper?

Thanks again,
cp

Mark DiSilvestro · #13 10-01-2008, 05:49 PM

Quote:

Originally Posted by chris1968230110

Wow Mike, thank you!

I'm printing this all out.

I'm going to try both solutions. The mechanical pump was quite easy to install so I'll try it first.

Yes, there was a spacer, and I do think there was a right angle adapter...

Is a proper gasket very important for the mech pump or can I use any gasket paper?

Thanks again,
cp

Yes you can make a gasket.
My 70 250 engine uses the pump with the right-angle adapter, while my '72 250C has the pump that bolts right onto the block. When I looked up a new pump for my 250 awhile ago, sources claimed the old-style pump that needed the adapter was no longer availble. Only the direct bolt-on type was listed, and there was no mention if the newer pump could be substituted for the one that used the adapter. It sounds like they may be interchangeable if someone got the later syle pump to work on your 200, but compare the pump-mounting setups on your 200 and 230 to be sure.
If you're gong to try the 200 mechanical pump on the 230, you'll need to install whatever spacers and gaskets were on the 200, and probably eliminate the right-angle adapter setup that's now on the 230.

Happy Motoring, Mark

Bcollia · #14 10-01-2008, 11:09 PM

There are two styles of fuel pumps. I wanted to order one when I first bought my 230S thinking it would be around $50. I did some research and called Phil at Fast Lane only to discover that my "old style" fuel pump was no longer available and I would need a fairly complex and expensive retrofit kit. I decided to test my pump and she works fine. I actually have to put an inline fuel regulator on the line. If mine ever dies I'm going to go with a decent electric replacement instead of the expensive retrofit kit. If you have the new style the cost was fairly low, like $50ish.

Good luck. When in doubt call Phil at Fast Lane.

chris1968230110 · #15 10-02-2008, 02:09 AM

Guys, thanks a lot!

I can't believe how helpful this forum is.

Bcollia, I bought a new OEM Mehle mech pump for around $50 at German Star. Ron can pretty much get anything. That pump is great and is what I want to put in the 230.

For an electric pump, which PSI range is better? How can I prevent fuel flooding or will that be a problem?

1.7 to 2.28 PSI ?

or

2.13 to 2.84 PSI?

Thanks again!

cp