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Stock fuel pressure regulator with new walbro 255 pump?

fuel regulator furl pump walbro 255

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#1 supernova_6969


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Posted 25 September 2015 - 09:16 PM

Hi guys!


My car (L28e, turbo-ed up, with megasquirt, see my profile for details) came with the stock fuel pump and fuel pressure regulator (FPR) attached, and with a brand new, uninstalled walbro 255 fuel pump.  The previous owner told me the original pump was starting to show fatigue at high boost/high RPM.  


I haven't seen any signs of fuel starvation under any circumstances, although I am getting crazy, all over Air/Fuel Ratio (not under high boost/RPM).  Now, my megasquirt is currently tuned like crap (litterally,  really really really badly) which probably cause a significant part of those fluctuations;  I also suspect that some injectors might be bad, or something else, so I'm not changing any AFR settings until i test out the injectors (in a few weeks, once I park the car for winter).


Long story short, I thought it might be cool to install the new fuel pump..  it looks nicer, it'll probably buzz less than the old one (mmmmmwiiiiiiiiiii.......), and it'll eliminate the possibility that the pump is contributing to my AFR woes.  


HOWEVER!  I've been told by a friend who's a mechanic that the more powerful pump will most likely kill the stock fuel pressure regulator.  I'm inclined to try it with the stock FPR, but don't want to drive to work and have the car die on the way there from the new, awesome power of insane fuel pressure (echo, echo, echo....).


I don't have a lot of money to put on the car (read no money at all) so I'm curious to see what other people think of the issue, what are your personal experiences, before I try anything out.


Thanks a million!



#2 NewZed


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Posted 25 September 2015 - 09:55 PM

The only way it could "kill" the FPR is if the flow rate was so high the pressure built up and blew the diaphragm.  I've never seen anyone report this.  If you have a pressure gauge you'll know immediately if the FPR is in danger.


Your friend pulled an Ace Ventura on you.

#3 Zetsaz


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Posted 25 September 2015 - 11:16 PM

I'm running a Racetronix fuel pump in my L28E (Also 255LPH, just like your walbro). The pump was really made for an 99-03 LS1 setting, but it's in my my F-body tank feeding my stock L28E engine and I have no issues at all. My engine's probably the best part about my car right now actually.

#4 supernova_6969


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Posted 27 September 2015 - 04:01 PM

Thanks guys.  I appreciate the input.  loloks like I might go with it the way it is...


I'd actually love to have a fuel pressure gauge, as it could help me figure out whether the current stock pump is doing it's job (although I guess I'd have to run pretty fast to watch the gauge in action while under boost)...  Like I mentioned though, money is a bit of an issue.  anyone knows where a cheap one (ideally one where the needle sits in liquid) can be found?


New Zed.  I love Ace Ventura, but I'm failing and don't get the reference..  oh!  talking through his ass.  yeah.  The guy is a good mechanic, but very nervous, very by the book.  He was probably taught that that's the way to do, it, so he's not budging.  


Any one else can share experience?  

#5 bradyzq


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Posted 28 September 2015 - 10:55 AM

You could check the spark plugs and see if they're more or less equal in colour. That would point out any cylinder-to-cylinder differences, maybe due to injectors, or not...


Next, and I seem like a broken record to myself regarding this (and I actually do have a turntable that won't go to the end of a record and lift, so it skips and repeats), make sure you have good voltage to the pump. This means good wiring on both power and ground sides, ideally straight from the battery, with the original wiring being used only to trigger a relay near the pump. This is especially important when the wiring in question is over 30 years old!!

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#6 supernova_6969


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Posted 26 September 2016 - 06:42 PM



quick update to an old thread.


the stock pump was doing ok (I used a t junction after the fuel filter, and ran a hose from that, outside the engine bay through the open hood, right in front of the driver;  i was able to monitor fp in real time..)...  but I still decided to change it, just in case. I installed the walbro 255 on my car, complete with a fresh new 12 ga wire straight from the battery (through a fuse and a relay triggered by the original wire)...  


Walbro pumps have a stupid metric thread and it's hard to find the proper fittings, so I ended up having to use 1/8 npt that I re-thread to M10 (they are almost the same, so that was VERY easy) on the "out" side, and on the "in" side I ended up making my own fitting with a lathe...  the "in" side comes from a 12mm hose which is too big for anything that is commonly available in 1/8npt...


long story short, the regulator is still alive, regulating away like a champ...  as far as i know..  :-)


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