MFI Timing.....??? Photo neededq
 

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

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?

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."

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.

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

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

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.

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

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

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

http://forums.pelicanparts.com/uploa...1244728148.jpg

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

http://forums.pelicanparts.com/uploa...1244728726.jpg

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

http://forums.pelicanparts.com/uploa...1244729272.jpg
© 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.

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

http://forums.pelicanparts.com/uploa...1244738192.jpg

http://forums.pelicanparts.com/uploa...1244738222.jpg

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

http://forums.pelicanparts.com/uploa...1244738344.jpg

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.

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

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


http://forums.pelicanparts.com/uploa...1306661377.jpg

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.

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).

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

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

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