Author Topic: 1964 230SL injector pump only feeding one cylinder  (Read 1360 times)

mistertj

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1964 230SL injector pump only feeding one cylinder
« on: December 01, 2024, 21:04:31 »
I posted what is below earlier today. Since that time I did more testing / trouble shooting. Disconnected and bagged the rest of the pump lines at the injectors. After cranking the engine many, many times, found that only injector line to cylinder #2 is producing fuel. The others are dry...totally dry. Any insight as to what is going on and possibly how best to fix, would be greatly appreciated. Have attached a few photos.


Been a year since I last posted on my 230SL cold start issue. I have made no progress since I haven't really done anything until now. Summer is long over so nice cooler working weather is here, I'm back at it. I did, however, do some things...filters, etc and have fuel pressure of around 7psi. (See photo) I also followed a couple of the previous suggestions and disconnected a few of the lines to injectors 4, 5 & 6.(See photo) Cranked the engine numerous, numerous times and no fuel coming out of the lines. No fuel to the injectors is the symptom and certainly would cause hard / no starting.
So...before I start disconnecting metal fuel lines, I wanted to ask for any input as to what might be going on and what my next steps should be before I start taking things apart. Car has been sitting for a year so there might be an air lock or whatever. Thank you in advance for any thoughts.

Kevkeller

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Re: 1964 230SL injector pump only feeding one cylinder
« Reply #1 on: December 01, 2024, 23:58:52 »
Sounds like your injection pump pistons have frozen. Not too hard to get them moving again. There’s plenty of posts on the subject.
1970 280 SL

ja17

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Re: 1964 230SL injector pump only feeding one cylinder
« Reply #2 on: December 10, 2024, 04:52:56 »
Good suggestion from "Kevkeller" !
Joe Alexander
Blacklick, Ohio
1969 Dark Olive 280SL
2002 ML55 AMG (tow vehicle)
2002 SLK32 AMG (350 hp)
1982 300TD Wagon turbo 4spd.
1963 404 Mercedes Unimog (Swedish Army)
1989 flu419 Mercedes Unimog (US Army)
1998 E430
1974 450SLC Rally
1965 220SE Finback

mistertj

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Re: 1964 230SL injector pump only feeding one cylinder
« Reply #3 on: December 10, 2024, 14:15:52 »
Kevkeller - Your comment captures what I found the situation to be. All 6 cone valves were frozen and a number of pistons along with the rack. I think the #5 piston was the one really stuck but I treated all of them the same and with carb cleaner and penetrating oil, freed them up. The cone valves were easier to free up and once cleaned operate smoothly. I fashioned a puller to put pressure on the rack while I worked on the pistons. All came together nicely. Now waiting on new valve seal washers so I can put everything back together.

Thanks for the input.

TJ