Author Topic: 1967 230 sl injection pump timing  (Read 4048 times)

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1967 230 sl injection pump timing
« on: March 23, 2006, 06:33:03 »
I have a new injection pump that was installed and ever since then it has never run just right. I checked timing and cold start. I have tried adjusting the allen also at operating temperature.
So what happens is under load at about 3200-3500 rpms it breaks up coughing and popping and as soon as I back off its fine. I would like to pull the pump back out and check the timing on it or replace the pump there is some room for adjustment but it seems to be out of setting range. Do you have the timing specifications?

ja17

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Re: 1967 230 sl injection pump timing
« Reply #1 on: March 23, 2006, 23:32:29 »
Hello mrbenz,

"check all basic tune-up settings before altering complex fuel injection settings." A simple adjustment or replacement of an inexpensive tune up part will often solve the problem preventing comlex and expensive injection system repairs.

Many times the most complex, expensive and least understood system on these vehicles (the fuel injection) is the scapegoat for every engine problem which arises.

Injection pump rebuilders state that many of the injection pumps sent to them have nothing wrong with them.

The morale here is don't jump too soon.

I would check the linkage adjustment, do a fuel volume and pressure check and double check all tune up settings. Check the ignition timing with a timing light at 3,000rpm.

Replace the spark plugs one last time just in case they have become fuel fouled during the set-up process. This may be the best six dollars you ever spent. You can always save the removals for spares or the next tune-up, if this turns out not to be contributing to the problem.

Make sure that the oil level is correct in your injection pump!

Injection timing on this type of injection not very critical and usually will not cause such drastic problems as you are experiencing. However you may not rest until you have double checked it!  So if all else fails, the marks on the injection pump are lined up and the pump is installed with the engine at 20 degrees after top dead center of the compression stroke of # 1 cylinder. Be careful not to install the pump 180 degrees off! Verify compression stroke by viewing the camshaft lobes over #1 cylinder are pointing basically upward when the pointer on the engine is on 20 degrees  after TDC!

If you need more details on the above just let us know. Ask lots of questions.

Good luck!



Joe Alexander
Blacklick, Ohio
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

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Re: 1967 230 sl injection pump timing
« Reply #2 on: March 25, 2006, 08:09:46 »
Hello Joe , I have checked the timing 30 degrees at 4500 rpms vacuum disconnected, dwell 34-41, new points and condensor, dist cap rotor and pulled the plugs drained the fuel tank changed the fuel filter, Today I will pull the injectors and pressure test them and clean them out.I will let you know what I find before I change the pump or pull it out.  
                                   Thanks for your response

rwmastel

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Re: 1967 230 sl injection pump timing
« Reply #3 on: March 28, 2006, 21:33:56 »
MrBenz,

To reiterate some of Joe's comments that you did not reply to:

Don't forget to check the adjusted length of all the FI linkage.  Check for slop/play in linkage joints.

Draining the fuel tank and replacing the fuel filter (there are 3!) does not guarantee correct fuel pressure and flow rate.  Test these.

Did you check the oil level inside the injection pump?  Perhaps it was shipped from the rebuilder "dry"?

Rodd
Powell, Ohio, USA
1966 230SL, Euro, Auto, Leather, both  tops
1994 E420
« Last Edit: March 28, 2006, 21:34:18 by rwmastel »
Rodd

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