Fuel filters 3.5L Honda

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wopachop

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Hi all you duners!! Hoping to get this motor fired up before vets. Hasn't started in over 10 years. I see a sticker that says 3PVF-AA5.

They want to go filter, fuel pump, filter. We were about to buy another Bosch F5021, but then wanted to check specs to confirm it can be used on the pressurized side of the pump.

The more i read the more mixed reviews i got about which filters work best upstream vs downstream.

Figured asked on GD and get a solid answer. We have the one bosch F5021 and can use that either upstream or downstream. 

Will (2) Bosch filters become too restrictive? What 2nd filter should we get, if any? 

Also where do most duners buy FPS fittings? 

Any advice on preparing the motor for its first cold start is appreciated too. We drained the coolant and oil. Im happy to lube the cylinder walls however you guys recommend. 

20210927_140017.jpg

 
I always run aeromotive stuff for filters. I get my push lock fittings from Kartek. They are stocked up pretty well. 

 
Jaybird95 said:
It should be the other way around.
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Naw, he's correct.  The pump can handle much larger objects without failure, and restrictions (10μ filters, for example) can cause cavitation.  You also don't want your fine filter as the first filter since it will clog quickly.

 
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oh man, here comes a debate.  I have heard it both ways.  My Honda has the smallest before the pump, big after the pump................I have always thought that was weird, but trusted my builder (at least that what was relayed to me)

 
Cookie said:
oh man, here comes a debate.  I have heard it both ways.  My Honda has the smallest before the pump, big after the pump................I have always thought that was weird, but trusted my builder (at least that what was relayed to me)
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You want the least amount of restriction to the pump as possible. 

 
Cookie said:
oh man, here comes a debate.  I have heard it both ways.  My Honda has the smallest before the pump, big after the pump................I have always thought that was weird, but trusted my builder (at least that what was relayed to me)
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So both ways, I don't run a filter after the pump. Been 4 years and no issues.

 
richard h said:
So both ways, I don't run a filter after the pump. Been 4 years and no issues.
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I was told to always run a filter after the pump in case the pump starts to fail and to stop any pump pieces from going into the motor...............

 
Cookie said:
I was told to always run a filter after the pump in case the pump starts to fail and to stop any pump pieces from going into the motor...............
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Probably not a bad idea, just never done or had any issues. Of course now that it's been spoken about------

 
richard h said:
Probably not a bad idea, just never done or had any issues. Of course now that it's been spoken about------
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If I was only going to run one filter I would run after the pump. A fuel pump is always cheaper than a motor. Pre pump filter only protects the pump. 

 
Finer filter after pump regular filter before pump.I ust one of those boschs for post post on my honda easy to find easy to get.My pre filter is a small holley that i can clean out the screen,

 
Thanks everyone. Do you guys run a check valve after the pump? We have this pump that comes with a check valve. I see that Kartek has 2 options. 

1. Adapter  that uses a fitting. Around $50. 

2. Phenix Industries  complete check valve $40. 

The pump came with a AN-6 fitting that would work just fine if there is a benefit to omitting the check valve for this type of application. 

 
I dont run a check valve on my setup, but now thinking about it probably would not be a bad idea as I have a ton of bleed off one the pump is turned off.

 
wopachop said:
Thanks everyone. Do you guys run a check valve after the pump? We have this pump that comes with a check valve. I see that Kartek has 2 options. 

1. Adapter  that uses a fitting. Around $50. 

2. Phenix Industries  complete check valve $40. 

The pump came with a AN-6 fitting that would work just fine if there is a benefit to omitting the check valve for this type of application. 
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Helpful, but not necessary unless your pump is above fuel level since it would only prevent fuel pressure from backing up past the pump when off.  Most ECUs prime the pump when turned on anyway to combat this. 

 
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