MFI Timing.....??? Photo neededq

[signature65]

Hey all Im getting ready to time my MFI and I need a close up pic of the mark on the pump pully.....mine is old and I want to make sure I get it perfect.

So if anyone has a pic of the pully with the mark visable I would love it....

thanks

[signature65]

So i tried lining my crank 400 degress after TDC for cyl 1 and matching the line up on the pump that I think is right.....but!!! The teeth on the belt and pully dont line up. In fact they are exactly on top of each other. What gives?

[tharbert]

I believe the pulley can be loosened to allow for exact adjustment. According to Lee Rice "Small adjustments can be made with the belt in place. Use a 5mm allen wrench to loosen the three pump pulley bolts and adjust it to align the marks."

[Bobboloo]

As Tharbert says you can loosen the pulley on the pump and make minor adjustments.

My understanding is that the MFI pump timing is not critical. I would think that it's best to err on the side of being early so that the gas charge will just end up waiting for a moment for the port to open. You could probably be way early and it wouldn't even matter.

[signature65]

does anyone have a pic of the timing mark on the pully?????

[HawgRyder]

If I remember correctly....Porsche tried indexing the timing out by several teeth to see if it would effect power.
If memory serves...it did nothing to reduce power until you got more than 5 or more teeth out either way.
Bob

[356RS]

Darren, I can post a picture of the timing mark tomorrow if you still need it. I'm at home now and the photos are at the shop.

[signature65]

356rs that would be awesome. My pully is worn down and beat to death.....so a pic would be great.....thanks

[73rustbucket]

The pulley is slotted to allow for a perfect adjustment. Lossen the hex bolts and turn.

[David E. Clark]

Here is a drawing that shows the timing mark on the pump:



and a picture that shows the corresponding mark on the sprocket:



Here is the page from the factory workshop manual explaining the procedure:


© Dr. Ing. h.c. F. Porsche A.G. Posted here for educational purposes only.


Post #6 in this thread explains the procedure for replacing the belt and setting the timing.

Most MFI folks have concluded that getting the timing exactly perfect is not necessary. I fall in the camp of doing it the way the factory recommended since it's not much harder and I figure that they must know more about their product than I ever will! Good luck.

[356RS]

David got you what you needed. Should be easy to figure it out now. Just in case you need a few more photos......





If you need a new pulley, I have some that are made by Jay Moore. Very high quality.

[signature65]

Thats exactly what I needed.....thanks guys.

I thought the mark was on the pully itself. Seeing its on the hub makes more sense.

MFI scares me and I have been doing all the CMA I can while it has been off the engine. Now its time to set the rest up and see if it will run.

[philippeF]

Originally Posted by 356RS

David got you what you needed. Should be easy to figure it out now. Just in case you need a few more photos......





If you need a new pulley, I have some that are made by Jay Moore. Very high quality.

Hello Mark
Any idea of the price for the pulley ?

I'm looking for a little internal spring for a MFI pump, would you help me ?
PM if you want
best regards
Philippe

[304065]

http://www.pelicanparts.com/catalog/shopcart/911E/POR_911E_FULmfi_pg1.htm#

[Eddyvdw]

Again, what an amazing site this is. Also I was looking on the mark on the toothed wheel.....
The mark is hardly visible though. Tried to scratch it a bit and I feel a little dent.
What are the symptoms of a mis aligned pump?

Ed

[bavaria911]

Looking at these pics, the belt seems to be slipping off.
What year did the sprocket on the pump gear have a cover to keep the belt from slipping off. I did see one for sale a ways back on ebay and here.
Are they worth having on a 1972-73 pump gear?
Thanks in advanced.

[Flieger]

They are usually pretty tight on there. I have never seen one with a flange to retain it, but I have never seen one need it (have a belt slip off).

[356RS]

Originally Posted by bavaria911

What year did the sprocket on the pump gear have a cover to keep the belt from slipping off.

The toothed gear on the cam is the one with a flange lip. There was never one on the pump gear.

[moshik1958]

Originally Posted by 356RS

David got you what you needed. Should be easy to figure it out now. Just in case you need a few more photos......





If you need a new pulley, I have some that are made by Jay Moore. Very high quality.

Hi
i am trying to find the mark on my mfi pump (not the yellow mark, the one on the pully))
i looked very carefully but no mark on the pully
i must check the timing, is there any way to do it without the mark on the pulley?

thx

[john walker's workshop]

The mark is on the flange that the pulley attaches to, not on the pulley itself.