Pagoda 230 SL fuel problems

[jose230sl]

Hello, I have a 230 SL 1965, the car starts ok and run but after a couple of miles the car loose power and stops, it starts again. then I have the same problem 2 or 3 times again, looks like the fuel pressure is gone for some minutes. I need some help. the fuel pump has been rebuilt, the injection pump is working fine, so I don´t know what to do.

[JamesL]

Hello, and welcome to the group. I am sure someone will reply in a very helpful way

[jose230sl]

Thank you

[dirkbalter]

I would measure the amount of fuel returned to the tank to insure your fuel path is sound. (At the end off return line prior to going back into the tank).
If you read through the related section in our tech manual, you will have a good idea on what you want to see with respect to l/sec or so.

[Pawel66]

I am proud to admit I thought what dirkbalter wrote (he is an expert, I am an amateur).

This simple test shows overall flow efficiency of the fuel system, including return line (yes, if return line is clogged, you will have fuel starvation of the engine). Measure the flow of fuel at the end of the return line (at the tank). Put the end of return line into a canister  - something you can see and measure fuel volume. Switch on the fuel pump for a couple of minutes to worm it up, then measure the flow. You should get, say 0.8 liter in 15 seconds, better if more. If it is 0.6 liter or less - there is a serious blockage in the fuel lines.

If you diagnose the block, go step by step: first filter is the screen in the fuel tank outlet, then there is a screen in the inlet of the fuel pump (if you do not have in-line filter before the fuel pump), then there is the main fuel filter, then there is return line that may be clogged (be careful if you decide to blow it through with the air, put some cloth around the opening).

Do not blow air to the tank. Be careful and take precaustions when working with gas.

[Bonnyboy]

The symptoms sound very typical of a clogged flower pot in the fuel tank -  rust settles in there and blocks the fuel flow.  Lots of info on the site.

May be time to have the fuel tank cleaned.  You may need to remove the tank to determine if it is rusted out -  they can rust from the top down and chunks of rust will fall into the fuel and clog the flower pot. 

[jose230sl]

Thank you very much folks, I will do that this weekend and let you know, so far, I clean the tank and the lines, but I didn´t check the amount of fuel in 15 seconds. Grate
Thank you very very much

[dirkbalter]

Pawel, danke fuer die Blumen  . But I am no expert. Its all about learning by doing and it is amazing how much you learn over time.

On the above subject, I had a fuel cut off problem on my 280. It would randomly shut down and stop..... sometimes it would start again or not.
It turned out to be the connection of the fuse in the fuse holder. After cleaning the fuse holder contact, everything is good again. (You should be able to hear the pump running all the time)   

[Pawel66]

Well, to me you are.

It is about eliminating things. The fuel flow is one of the simplest tests. I had a very similar issue and it did turn out to be clogged filter after car restoration and a new tank - even then you get trash in the tank.

[Bonnyboy]

Checking the volume of fuel heading back into the tank will tell you lots.  I had a rusted tank and then found a pinched return fuel line under the car and then determined that there was not enough volume coming back into my tank.  A new fuel pump fixed that.

[jose230sl]

Hello, thank you very much, I did what you suggested and checking with 15 seconds at the return fuel line I have less than 0.8 lt, so we checked the fuel line and we found a problem there, we are going to fix the problem today and let you know.

[Pawel66]

You may want to consider fitting an in- line filter between tank and fuel pump. Fuel pump should have a screen in the fitting, but still…

Just be careful - if you have original fuel lines they are 9mm ID. Most filters are 8mm. So either do it the Kent’s way - fit short lengths of hose on filter fittings to increase their diameter, or find filter with 9mm fittings.

[rwmastel]

the fuel pump has been rebuilt, the injection pump is working fine, so I don´t know what to do.

What you do is work with facts, not assumptions. You got good advice and hopefully you found the problem.  If the flow rate is still low, let us know.  You can also search the forums or look in the Tech Manual for measuring frel pressure.

[jose230sl]

Hello, we finish yesterday, the problem was at the fuel line, now I have exact the 0.8 lt per 15 second and the car doen´t have any problem, I am very very happy to join the Pagoda Club, thank you all.

[jose230sl]

A question, the filter you are talking about, do you have something that works good?
Thanks

[dirkbalter]

A question, the filter you are talking about, do you have something that works good?
Thanks

Pawel already mentioned it:
https://mercedessource.com/store/early-fuel-injection-electric-fuel-pump-pre-filter-upgrade-kit

You can do it yourself as well. The biggest (simple) FAM fuel filter I found was 3/8" ( 9.5mm).
Once installed, you can tell right away if you have debris in your tank. More important, you don't want to get that debris into you fuel pump.

[Pawel66]

Something like this: https://poltechparts.pl/pl/p/Filtr-paliwa-Catepilar-P550974/8787?gad_source=1&gclid=CjwKCAiA9IC6BhA3EiwAsbltOG8s5voJaVthrHTHpChdf8BQY7n68b0WXNiRya7nAJaP3s6eBnBhGhoCW_kQAvD_BwE

Double check the OD of the fittings.

[dirkbalter]

or:
https://www.fram.com/fram-fuel-filter-in-line-g3

I like the clear ones so I can see and dirt or other coming from the tank. (I still have the original tank)

[Bshaunessy]

DIRKBAITER
 While I agree it’s good to have a see through gas filter, beware the plastic ones ( like the FRAM filter in the previous link).
I had one of these fail a few years ago, caused by vibration which made the plastic fitting break, which in turn caused a serious engine fire….( but luckily I was able to put out quickly with my on board fire extinguisher…..have one in every car).
  I replaced that FRAM style plastic filter with a much more robust glass and steel but still see through model, such as this K+N model:
https://a.co/d/gNfHMUX

[dirkbalter]

DIRKBAITER
 While I agree it’s good to have a see through gas filter, beware the plastic ones ( like the FRAM filter in the previous link).
I had one of these fail a few years ago, caused by vibration which made the plastic fitting break, which in turn caused a serious engine fire….( but luckily I was able to put out quickly with my on board fire extinguisher…..have one in every car).
  I replaced that FRAM style plastic filter with a much more robust glass and steel but still see through model, such as this K+N model:
https://a.co/d/gNfHMUX

Thank you and good to know. I definitely will keep an eye on it.

[jose230sl]

Thank you, I will go for the last one, have a good weekend

[jose230sl]

Hello again, I just found in my spare parts a long fuel pump the earlier, it is working fine, what is better, the long or the short fuel pump? Thank you all
 Another question, my car doesn´t have A/C it is possible to install one, if yes where can I found a good one?
Have a nice weekend

[Jonny B]

You can check at Bud's Benz website - https://www.budsbenz.com/catalog/230-250-280-sl/z-air-conditioning

They have a current a/c unit available. It fits under dash as the original ones did, but Bud's is not the same style.