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tii fuel pressure check and fuel pump replacement

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Onto my next trouble shooting escapade.. what tool do you guys use to check fuel pressure on a 73tii.  Was going to disconnect the line after the filter and put a guage there...


Next, in case I need a fuel pump. Anyone use one of these?




Says it has a max fuel pressure of 30psi. tii needs 28. Should be fine. Inline.


I have a spare one, but not sure if it works... Can you dry check a tii fuel pump?



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Hi Roman,


That pump will require barbs at both ends. 



You want something with nipples (8mm inlet , 6mm output), and it helps if they include the electrical hardware, as you may have an old connector that is hard to mate up to.

Image result for 16121107414

Search on BMW p/n 16121107414 and you'll find plenty.

The Bosch pump is the "real deal" https://www.mister-auto.ch/fr/pompe-a-carburant/bosch/0-580-464-070/#product-item-characteristics, but I think these other pumps are also good.  (I get EU sources because my IP address is here, but you'll likely get domestic hits.)

They mostly have 3 bar output, or 42PSI.  That Summit pump at 30PSI would work, but it's operating at the top of its output, and if they are 10% off their spec, you're under pressurized.


I have tested my spare pumps by shooting some WD-40 into them and letting them spin very briefly just to confirm they were not frozen.  You could use kerosene or turpentine if you wanted to verify the flow rate.  I think it's supposed to be just under 1 liter (85ml?) in 30 seconds.


These pumps have a smaller diameter compared to the original, so you will need a piece of 1/8" rubber to wrap around it.  I have used rubber placemats, and most recently a section of heavy sound isolation material from a sound-proofing project.


I have my pressure gauge installed between the filter next to the radiator and the input to the Kugelfischer Pump dual banjo fitting.  (The gauge is face down in this picture.)



Here are a couple of good guides from a great Tii blog:

Fuel Filter Upgrade 2002Tii.pdfFuel Pump Installation.pdfFuel Pump Restoration.pdf

Edited by Swiss 2002Tii
additional info

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A good place to check the pressure is between the KF pump banjo bolt line that leads to the cold start valve. Ideal pressure is 28 psig.





This is what the stock tii Bosch fuel pump looks like



My spare assembly looks like this (I've been running the E30 318is in tank pump since October 2010)







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Terrific cut-away drawing of the system Jim!

That's a good placement idea.  I am going to add a pressure gauge sensor; this is a good location.

And it looks like you polished the top of the tuna can?  Nice!

Edited by Swiss 2002Tii

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4 minutes ago, Swiss 2002Tii said:

Terrific cut-away drawing of the system Jim!

Credit for that enhanced graphic goes to long-time FAQ early member c.diesel  (Creighton Demerest) who hasn't posted here in a long time.

Here's the front view


Edited by jgerock

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