MFI fuel filter overflow/diverter valve help.

[cmpski]

My understanding is these are supposed to hold about 14 pounds of pressure. About 1 bar. We ordered a new one from Stoddard. The spring only holds 2 to 3 pounds. We can't hold enough pressure to start a new MFI engine build. It looks like this one is for a carb engine. Was there a Porsche carb engine that used one of these?
Does anyone have a NOS Bosch one for MFI they would sell me? I need help, and a good NOS one of these. Our old one had a 9 stamped on it and nothing else. Any insight would help. We have tried 3 fuel pumps and they all deliver the proper 900 to 1000 cc's in 30 seconds to the engine compartment. When we pinch the line headed back on the return line next to this valve we get fuel pressure. Help.
Chris

[Jonny042]

Are you positive you have the 4 hose connections correct on the filter console? It's not exactly intuitive, easy to get wrong, and apparently some of the early service information had incorrect hose routing diagrams, to make matters worse.



This may help you understand how it should work:

Originally Posted by Jonny042

For me, there's no replacement for understanding how something works, so you can just look at it and verify that it's assembled/adjusted/connected/working correctly, so you don't have to rely on 50 year old documentation that may not be correct.

In the case of the fuel filter console, how it functions is not immediately apparent. It's actually a pretty wondrous little bit of clever engineering, but I didn't understand exactly how it worked until I had one on my MFI test stand, flowing fuel, with clear hoses.

Posts #453 & 454 of my build thread is titled "Mysteries of the fuel filter console - revealed!" which sounds pretty dramatic but I had not seen anything explaining how it works before:

Project Heavy Metal - an all steel classic, remastered

Project Heavy Metal - an all steel classic, remastered

It's worth a read. I've been meaning to post the text and pics in the MFI resources thread.

[r lane]

I have gotten them from the dealer, part # 901 110 915 00