Author Topic: HELP.... FI Pump install. Was I on the Compression stroke?  (Read 2886 times)

jf308

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HELP.... FI Pump install. Was I on the Compression stroke?
« on: October 05, 2014, 00:30:48 »
Followed the IP "free up" and Install Threads on the Forum, and didn't see any reference to Compression Stroke or Exhaust Stroke.  Just the reference to20 ATDC. 
Installed my FI Pump (for the second time after finding out that two pistons were stuck).... now I am concerned that although the marks on the IP were aligned, and I was at 20 ATDC, I may not have been on the COMPRESSION STROKE  (Not a mechanic, and learning from this forum and repair manual documents on my first time.  I now tripped over a reference to it being REQUIRED for correct alignment?

Having trouble determining the Compression TDC... when I re-set back to the ATDC when I installed the pump, my rotor was pointing toward the plug wire position closest to the vacuum diaphragm unit on the side of the distributor.  If I understand the wire position, this is near #6 and opposite #1.  

DOES THIS MEAN THAT I AM 180 degrees off?

I have read this link, but am not confident that I have Compression or Exhaust.  

http://www.sl113.org/forums/index.php?topic=16056.0

Thank you.   Hopefully the Second time was the charm, and not a THIRD Remove and Re-Install.

John
« Last Edit: October 05, 2014, 00:36:27 by jf308 »

ja17

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Re: HELP.... FI Pump install. Was I on the Compression stroke?
« Reply #1 on: October 05, 2014, 05:11:33 »
Hello John,

Yes sounds like you may be off 180 degrees. The camshaft lobes over a cylinder under compression will be pointing  basically upward (closed).



















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

jf308

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Re: HELP.... FI Pump install. Was I on the Compression stroke?
« Reply #2 on: October 05, 2014, 12:54:47 »
Thanks Joe....

Other than feeling for the compression within the spark plug hole (difficult to do with one person or without a pressure gauge).... is there another way to confirm that the cam lobes are up (closed valves)?  Can you look at the direction of the rotor to help with this?

or do I just need a pressure gauge to be certain?

ja17

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Re: HELP.... FI Pump install. Was I on the Compression stroke?
« Reply #3 on: October 05, 2014, 14:27:12 »
Just take the oil filler cap off the valve cover and take a look at the first two cam lobes.
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

jf308

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Re: HELP.... FI Pump install. Was I on the Compression stroke?
« Reply #4 on: October 05, 2014, 14:37:25 »
Perfect.  Now I understand.  Was wondering how to check the cam lobe position.   THANK YOU.

I was so pleased that I got the IP freed up that I didn't read the details of the forum thread or my workshop manual carefully enough.  Learning experience for me.

I just re-read the workshop manual, too -- and it does remind folks (or dopes like me) that the 20 ATDC should be on the COMPRESSION STROKE (check by removing the spark plug and feeling the compression or by checking the rotor arm of the distributor pointed towards the No. 1 HT lead contact in the distributor).

The #1 from the diagram is opposite side of the vacuum diaphragm device on the side of the distributor.

So, from all sources -- it looks like I am off 180 degrees.  

IP coming off for time number 3 today.    :-)

But I am having fun, and learning a lot about these wonderful cars.

John
« Last Edit: October 05, 2014, 14:57:26 by jf308 »