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Fuel check valve?


Hodgepodge
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I'm reworking/replacing my fuel lines to improve cold-starting.  

Somebody suggested adding a check-valve to the fuel line to help ensure that there is fuel at the pump when the car is started cold or has sat for long periods.   

 

3  short-as-possible questions:  Oh. 4. 

 

1.  Does an additional check valve in the fuel line make sense?   Don't the fuel filters act as check valves?  

2.  Where do I get a fuel check-valve that will work with my '05 fuel lines?  I see a BMW check valve that works with the VAPOR line, but not fuel. (11631707770).

3. When I get it, where should it go to help ensure that there is fuel in the pump when I start the car cold? 

4. Does the current set-up, with the return line to the tank, drain the fuel from the lines or just relieve pressure?  This will be a fair-weather car and I don't want to do anything that will gum-up the fuel lines when it is in winter storage.   

 

As always, your thoughts on this are appreciated.  

 

Thanks,

 

Scott

 

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31 minutes ago, Hodgepodge said:

I'm reworking/replacing my fuel lines to improve cold-starting.  

Somebody suggested adding a check-valve to the fuel line to help ensure that there is fuel at the pump when the car is started cold or has sat for long periods.   

 

3  short-as-possible questions:  Oh. 4. 

 

1.  Does an additional check valve in the fuel line make sense?   Don't the fuel filters act as check valves?  

No. 

31 minutes ago, Hodgepodge said:

2.  Where do I get a fuel check-valve that will work with my '05 fuel lines?  I see a BMW check valve that works with the VAPOR line, but not fuel. (11631707770).

3. When I get it, where should it go to help ensure that there is fuel in the pump when I start the car cold? 

4. Does the current set-up, with the return line to the tank, drain the fuel from the lines or just relieve pressure?  This will be a fair-weather car and I don't want to do anything that will gum-up the fuel lines when it is in winter storage.   

Sta-Bil, and ethanol treatment ;-)

31 minutes ago, Hodgepodge said:

 

As always, your thoughts on this are appreciated.  

 

Thanks,

 

Scott

 

 

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5 hours ago, Hodgepodge said:

1.  Does an additional check valve in the fuel line make sense?   Don't the fuel filters act as check valves?

on 76 model there was a check valve at fuel return line. No

 

6 hours ago, Hodgepodge said:

2.  Where do I get a fuel check-valve that will work with my '05 fuel lines?  I see a BMW check valve that works with the VAPOR line, but not fuel. (11631707770).

BMW fuel none return valve part No. 13311263522 (NLA from BMW, but W&N has one for 45 Euros). The one echappe shown above will work just fine

 

6 hours ago, Hodgepodge said:

3. When I get it, where should it go to help ensure that there is fuel in the pump when I start the car cold? 

Only place BMW placed them on was at fuel return line after valve 13311259194 on late model 2002 

IMG_2860.thumb.JPG.80fa9282c5202cf5f5a28ae341894acc.JPG

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I picked a 3 pack of mine from amazon.

 

Think they were 20 bucks and made of aluminum.

 

I put one aft of the tank before the pump to keep the pump primed, then another ahead of my filter-king fuel filter (which sits just ahead of my carbs) to in theory do something which I don’t remember was my original thinking at the time.... but it all did indeed help!

 

 

Sent from my iPhone using Tapatalk

 

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I should preface this by mentioning that there are numerous versions of the 2002 fuelling

system, and many ways they've been modified since.  So y'oughta tell us what ya gots, there...

 

Since Jim has not chimed in, any restriction on the intake side of a mechanical pump runs the risk of

reducing its efficiency.  Fuel filter, check valve, whatevah.

 

That said, a very low- cracking- pressure valve probably won't hurt.

 

IF the fuel pump is working correctly and you have no air leaks in your intake line,

the check valve in your fuel pump itself should do everything you need.

 

What we've been finding is that the low volatility of modern fuels means that the float bowl

evaporates dry in an absurdly short time- modern fuel systems ave no opportunity for evaporation,

really, so there is little attempt to moderate it.

 

As to the return valve, it was a late- model thingy that

was only supposed to open at times of high manifold vacuum, to relieve pressure

on the needle valve.  So shut off, with no vacuum in the manifold, it should be closed.

I've only seen a few of these, and only one that actually worked as designed...

 

t

 

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3 hours ago, TobyB said:

Since Jim has not chimed in, any restriction on the intake side of a mechanical pump runs the risk of

reducing its efficiency.  Fuel filter, check valve, whatevah.

Dirt blocking the pickup screen will do it as well.  That's what I had just a couple weeks ago.  In August on my return from Durango on a hot day, I started to get a bad miss getting away from the traffic lights.  I blamed it on overheated coils because on cool days this fall, no trouble.

A couple weeks ago I took a fall drive up squaw pass, hot day back in town, same missing.  But the pump was noisy as it seemed to be getting more noisy over summer.  It had 40K miles on it and with EFI, it pumps at a high rate all the time.

Bought a new pump, it's an inline Bosch, same as the Tii guys have been replacing theirs with.  Installed and all quiet until a short drive around the neighborhood.  The new pump sounded the same as the old one.  Pulled the pickup and it was mostly covered with fine trash.  The pump was cavitating on the gas from the restricted suction line.

Edited by jimk
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