Remove MFI pump (how to)

[quickstep]

I want to remove my MFI pump (1969 E Coupe) so I can have it checked and restored/calibrated.
Can this be done easily or is it necessary to have the complete engine removed?

I checked the web and forum but there is no list of how this can be done.

Thanks.

[72targa]

Good question! Looking forward to the answer...

[edmayo]

It is done with engine in place. Degree of difficulty will depend on your experience, skill level, and tools.

[quickstep]

Will try on Wednesday with friend how has experience with engine maintenance. Will try to make some pictures and post them.

[422flat6]

Here's how I did it on my 72

First remove air cleaner assembly and stacks. This is pretty straight forward. Careful not to damage the cold start injection lines and little plastic NLA connectors.

Turn engine over to the FE mark as described in Check, Measure, Adjust
Disconnect electrical wires from overrun solenoid
Disconnect pre-heat hose
Disconnect fuel hard lines at injectors
Disconnect fuel hard lines at pump (right side first, then left side) 17mm flare crow's foot really helps here
Disconnect fuel soft lines
Disconnect oil lines
Slip drive belt off pulley, keep upward tension on it so it doesn't slip off the cam sprocket, hold it up with rubber bands or something while the pump is out
Remove four nuts that hold pump to mounting plate
Lift pump out

Reverse order to reinstall. Reinstall tips:
Look at timing marks on pump pulley before reinstallation. Optional: paint a white line on the pulley to make the mark easier to see.
Use adjustable inspection mirror on a stick and flashlight to verify timing marks are aligned.
Pump mounts are slotted, slide it on the mounting plate to adjust drive belt tension.
Reinstall left side fuel hard lines at top of pump connections first. Can't get a wrench on them with the right side connections in place.
Be careful not to over torque anything, especially the injectors in the head when reinstalling hard fuel lines at injectors. Hold injectors still with second wrench while torquing fuel hard lines. If you need to remove any injectors due to stuck fuel line connections, make sure you don't lose the copper seal ring on the injector. Preferably just take the injectors out and replace all the copper seal rings.
Use torque specs listed in the Porsche tech specs booklet.

Hope this helps.

[Rusty]

An additional note, when you set your FE mark at the case halves. Check the mark on the fuel pump with a mirror prior to removal. Both marks should be aligned.
Good luck with getting it off the engine. Send your injectors to the fuel shop with the pump. One more opinion, the throttle bodies should come off the engine as well.
Check for tightness and that the air adjusting screws have clean passages. How's the distributor advance and return. What performance issue is leading you to this decision?
And you thought you would just get a simple answer to your question.

[letsrollbabe]

For those of you who want to test/clean the injectors yourself, here is a great video from a Mercedes guy who shows how to test with a kit he has put together. It is well worth the price of approx. $180. I went through all my injectors and found quite a few that didn't do the spray pattern correctly nor at right pressure. The test kit can be used to clean injectors so that they spray correctly and at the 230 psi pressure.

https://www.youtube.com/watch?v=S0LX2kFPllk

[Hugh Lindberg]

Interesting...Were you able to get the injectors to work well enough, or did they get replaced?

Thanks, Hugh

[sithot]

Not a bad deal on the cleaning rig since the injectors are "dear" ($$$).
CIS injectors are about half price.

[letsrollbabe]

Interesting...Were you able to get the injectors to work well enough, or did they get replaced?

Thanks, Hugh

I was able to get 5 of 6 working properly after forcing a lot of mineral spirits and other cleaning fluids through the injectors. This 'tool' is one of the best investments I have made to help the 45 yr old MFI systems work properly. Cleaning the outside to make injectors look shiny is easy, but most used ones are going to need cleaning internally to get them to work properly. It is very satisfying to get them to 'chirp' at the 230 psi level and then hold pressure. I have been told by one of the MFI pump rebuilders that many of the new injectors don't work correctly...especially the ones that come in blue boxes (not yellow Bosch boxes).

I left the cleaning fluid sit over night inside troublesome injectors, and several were then checked and performed correctly. I think I found 3 out 12 that still dribbled fuel, and would not hold pressure. I will check them later after leaving them soaking in cleaning fluid to see if they come around.